Heterogeneous system photosensitive oxidation sensitizer

A compound selected from some classes of coloring substances having good resistance to light and oxidation is found to have a high photosensitive activity when it is supported in an actively dispersed form on a carrier. The sensitizer obtained is useful for heterogeneous system photosensitive oxidation for various purposes, for example, treatment of harmful organisms or impurities contained in the air or water. The sensitizer has also good resistance to light and oxidation and can be used repeatedly for a long time.

This invention relates to photooxidation by exposure to visible light using 
a novel sensitizer for photosensitive oxidation having excellent light 
resistance, oxidation resistance, water resistance and chemical 
resistance, including various uses thereof in such applications as 
purification of polluted air or water and inhibition of activities of 
harmful organisms. 
As the method for carrying out photooxidative reaction using a sensitizer, 
there have been known a homogeneous reaction system and a heterogeneous 
rection system. In the former method, a sensitizer is employed as a 
homogenous solution with a substance to be oxidized. Hence, there ensue 
such disadvantages as difficult recovery of the sensitizer after the 
reaction by separation and environmental pollution caused by the effluent 
of the sensitizer out of the system. 
In recent years, there is reported a basic principle that the reaction can 
proceed at a high efficiency even by use of a heterogeneous system 
sensitizer. For example, John R. Williams et al disclose photosensitizers 
comprising Rose Bengal, Eosin or Methylene Blue attached to ion-exchange 
resins (Tetrahedron Letters No. 46, pp. 4603-4606, 1973, Pergamon Press). 
Blossey et al also disclose photosensitizers comprising Rose Bengal or 
Eosin attached to chloromethylated polystyrene beads (Journal of the 
American Chemical Society Vol. 95, p. 5820, 1973). Furthermore, U.S. Pat. 
No. 3,951,797 discloses heterogeneous system sensitizers comprising basic 
dyes such as Methylene Blue or Toluidine Blue attached to hydrous gels of 
metal alginate. These methods are very attractive in commercial 
applications because the sensitizers can be used under heterogeneous 
conditions. 
However, in any of the reaction system, the sensitizing substances 
conventionally used in the prior art are all insufficient in physical and 
chemical stability. That is, such conventional sensitizing substances as 
Rose Bengal, Eosin, Chlorophyllin, Haematoporphyrin, Thionine, Methylene 
Blue, Toluidine Blue or Fluorescene are entirely insufficient in such 
properties. During usage, they may suffer from such changes as light 
discoloration, oxidative deterioration or hydrolysis to thereby lose the 
sensitizing function in earlier stages. Thus, these substances had the 
vital defect as being practically inapplicable. 
The substances well known in the art having photosensitive activity, 
including Rose Bengal, Eosin, Chlorophyllin, Methylene Blue, Toluidine 
Blue, etc. are inferior in such properties as light resistance, oxidative 
resistance, chemical resistance and water resistance. It would be rather 
antinomic to desire that a substance may have properties excellent both in 
photosensitive activity and in light resistance or oxidative resistance. 
Thus, it has been believed very difficult or impossible to obtain such a 
substance. 
From such a standpoint, the present inventors have made extensive studies 
to obtain a sensitizer for heterogeneous system photosensitive oxidation 
which can stand prolonged use and re-use, having excellent light 
resistance, oxidative resistance and chemical resistance. As the result, 
it has been found that a coloring substance having a degree of 
discoloration in the range from the rating No. 4 to the rating No. 8 can 
be supported on a carrier in an actively dispersed form to provide an 
excellent sensitizer for heterogeneous system photosensitive oxidation 
exhibiting stable photosensitive activity. The present invention has been 
accomplished based on such a finding. 
The sensitizer for heterogeneous system photosensitive oxidation referred 
to in the present invention comprises a sensitizing substance fixed in an 
actively dispersed form onto a carrier, which may be used in such 
heterogeneous systems as solid-gas phase, solid-liquid phase and 
solid-solid phase, depending on the phase of the material to be oxidized 
and the object of oxidation. 
According to the present invention, there is provided a method for 
treatment of a system containing harmful substances and/or organisms by 
exposure to a visible light in the presence of oxygen using a sensitizer, 
being characterized in that said sensitizer comprises a coloring substance 
having a degree of discoloration in the range from the rating No. 4 to the 
rating No. 8, said substance being supported on a carrier in an actively 
dispersed form so as to have a .DELTA.DO value of 0.5 or more. 
The sensitizer as specified above to be used in the present invention is 
novel per se and can be used for various purposes including heterogeneous 
photooxidation reactions other than such a treatment as mentioned above. 
According to the present invention, there is also provided a device for 
treatment of a system containing harmful substances and/or organisms, 
which is constituted of: 
(a) a part comprising a sensitizer as specified above: and 
(b) a means for irradiating a visible light, said part (a) being arranged 
so as to be contactable with the system to be treated and said means (b) 
being arranged so as to be capable of effecting irradiation of the light 
over said part (a). 
As mentioned above, the degree of discoloration of a sensitizing substance 
is a very important characteristic related to the light resistance and 
oxidative resistance in the present invention. Said characteristic may be 
evaluated in terms of the light resistance test value as determined by JIS 
Standard-LO841. Using Blue Scale as the standard, coloring substances can 
be evaluated and classified into eight ratings from the rating No. 1 to 
the rating No. 8. The rating No. 1 has the most inferior light resistance 
and the rating No. 8 the most excellent. As is well known in such fields 
as dye or pigment industry, plastic industry, paint industry, etc., 
various articles are desired to have a light resistance test value of at 
least 4 in order to stand uses in outdoors, namely under conditions of 
exposure to the rays of sunlight in an oxygen atmosphere. In fact, the 
sensitizing substance to be used in the present invention is also required 
to have a value of at least 4 so as to be durable in practical 
applications. As mentioned above, when a compound having a small light 
resistance value of 1 to 3 is used as a sensitizing substance, it may 
undergo light discoloration, oxidative deterioration at the outset of 
usage, thus failing to be practically used. Accordingly, it is required in 
the present invention to use a sensitizing substance having a value of 4 
to 8, preferably 5 to 8. On the other hand, the sensitizing substances 
well known in the art are found in some of water soluble xanthene 
compounds, acrydine compounds, thiazine compounds, triphenylmethane 
compounds and phenadine compounds. All of these compounds have inferior 
light resistance and oxidation resistance. For example, typical 
sensitizing substances such as Rose Bengal, Eosin and Fluorescene belong 
to the lowest class of the rating No. 1. Even Methylene Blue, which is 
regarded as having excellent light resistance, belong to the rating No. 3. 
It should be noted that the sensitizing ability and the light resistance 
were contradictory to each other in the above group of compounds. In other 
words, a compound having good sensitivity is liable to have a very poor 
light resistance, while a compound having good light resistance has no 
sensitivity at all. Such a tendency may well be understood, since a 
sensitizing substance is a kind of an oxidation catalyst which cannot help 
being itself oxidized simultaneously with oxidation of a material to be 
oxidized and therefore better sensitizing activity means worse light 
resistance or oxidation resistance. 
The present inventors have established a very rapid and accurate method for 
evaluation of photosensitive activity. As the result of measurement of a 
great number of compounds, there can be found a sensitizing substance 
excellent in photosensitive activity and also in light resistance or 
oxidation resistance from a very wide range of compounds. That is, some 
compounds belonging to the group of compounds having excellent light 
resistance and oxidation resistance, which do not exhibit any 
photosensitive activity when allowed to be present in the system alone, 
for example, as suspended agglomerates, are found to have absorption bands 
in the region of wavelengths from 380 nm to 800 nm and exhibit a high 
degree of photosensitive activity of 0.5 or more, sometimes 5 or more, in 
terms of the dissolved oxygen consumption value .DELTA.DO, when they are 
carried in an actively dispersed form on a carrier, thereby providing a 
sensitizer for heterogeneous system photosensitive oxidation having both 
excellent photosensitive activity and excellent light resistance. 
The dissolved oxygen consumption value .DELTA.DO referred to in the present 
invention is a value indicating a measure of a photosensitive activity of 
a sensitizing substance. It can be determined by dissolving a 
predetermined material to be oxidized in water having dissolved a certain 
concentration of oxygen therein and irradiating a certain intensity of 
light on the solution in the presence of a sensitizer. The percentage of 
dissolved oxygen decreased is defined by the following formula and can 
readily be measured by use of the testing apparatus as hereinafter 
described. 
##EQU1## 
wherein DO.sub.0 is the dissolved oxygen amount before the reaction, 
DO.sub.1 the dissolved oxygen amount after the reaction and .DELTA.DO the 
dissolved oxygen consumption value. 
To describe briefly about the evaluation method, a predetermined amount of 
furfuryl alcohol as a material to be oxidized is dissolved in water and 
irradiation of light is effected over the solution in the presence of a 
sensitizer at a predetermined intensity by use of a standard white light 
source as determined by J15Z-8902 a predetermined period. If said 
sensitizer has a photosensitive activity, photosensitive oxidation 
reaction of furfuryl alcohol will proceed, whereby the oxygen initially 
dissolved in the solution will be consumed. Thus, by measurement of the 
dissolved oxygen amounts before and after the reaction, the photosensitive 
activity of said sensitizer can be evaluated quantitatively within a short 
time. 
Such a dissolved oxygen amount can be measured by a titration method such 
as Winkler method or others, or by means of a dissolved oxygen meter. 
Especially, a dissolved oxygen meter enables rapid and accurate 
measurements. 
The dissolved oxygen consumption value .DELTA.DO as determined by the above 
evaluation method can be a good parameter for showing the photosensitive 
activity of a sensitizer for the following reason. That is, a sensitizer 
exhibiting a high .DELTA.DO value according to the above evaluation method 
is found to exhibit an efficient photosensitive activity in other 
photosensitive oxidation reaction systems, while that with .DELTA.DO value 
of approximately zero exhibits substantially no photosensitive activity in 
other photosensitive oxidation reaction systems. 
The sensitizer of the present invention is desired to have a dissolved 
oxygen consumption value .DELTA.DO as defined above of 0.5 or more, 
preferably 2.5 or more, most preferably 5 or more. With a .DELTA.DO value 
less than 0.5, the photosensitive activity is too low, whereby a 
photo-irradiation is required to be effected for promoting desirable 
oxidation reaction for such a long time as unacceptable in commercial 
applications. 
The coloring substance to be used in the present invention should have 
absorption bands in the region of wavelengths from 380 nm to 800 nm. 
Either a compound having absorption bands only in the region of 
wavelengths less than 380 nm, i.e. ultra-violet region, or a compound 
having absorption bands only in the region of wavelengths over 800 nm, 
i.e. infra-red region, has only very low photosensitive activity. 
Moreover, if such a compound is desired to be used, no visible light is 
available as a matter of course to a great disadvantage. Of course, said 
coloring substance may have absorption bands also in the region of 
wavelengths less than 380 nm or over 800 nm, insofar as it has absorption 
bands in the region of wavelengths from 380 nm to 800 nm. The position of 
the absorption band herein mentioned may readily be determined by 
measurement of electron spectrum. However, since such an absorption band 
generally exists as a broad peak, the absorption band should more strictly 
be defined in the present invention as a band having absorption maximum in 
the region of wavelengths from 380 nm to 800 nm, or as a band having an 
absorption coefficient .epsilon. as defined by the following formula of at 
least 1 in a part of the region of wavelengths from 380 nm to 800 nm even 
when there is no maximum absorption in said region. 
EQU .epsilon.=A/(c.times.b) 
wherein A is an absorption degree, c the concentration represented by g/ml 
and b the light path length represented by cm. 
According to the present invention, there have been discovered a number of 
sensitizing substances from a wide range of compounds subjected to the 
evaluation tests as described above, which have both excellent 
photosensitive activity as well as excellent light resistance or oxidation 
resistance, although both properties are in themselves contradictory to 
each other as hereinbefore mentioned. In particular, excellent sensitizing 
substances are found in the group of compounds which are insoluble in 
water and also in the group of compound which are insoluble in both water 
and conventional organic solvents. 
Typical examples of the sensitizing substances may be classified into the 
following groups of compounds (a) to (h); 
(a) aromatic ketone compounds and derivative thereof such as anthraquinone, 
1-hydroxy-4-aminoanthraquinone, N,N'-dibenzoyl--1,4-diaminoanthraquinone, 
benzoanthrone, anthrimide, pyranthrone, violanthrone, iso-violanthrone, 
dibenzopyrenequinone, anthranthrone, acedianthrone, etc.: 
(b) aromatic heterocyclic compounds and derivatives thereof such as 
arthraquinone carbazole, anthraquinone acridone, anthraquinone thiazole, 
anthraquinone thioxanthrone, anthraquinone oxazole, anthraquinone 
oxadiazole, dihydroanthraquinadiene, flavanthrone, benzoanthrone acridine, 
pyrazole anthrone, anthrapyrimidine, etc.; 
(c) aromatic hydrocarbon compounds or derivatives thereof such as chrysene, 
coronene, perylene, etc.; 
(d) azo compounds and derivatives thereof such as 
2,4-dinitrobenzeneazo-.beta.-naphthol, 
2-nitro-4-trifluoromethylbenzeneazo-.beta.-naphthol, 
4-methyl-6-nitrobenzeneazo-62 -naphthol, 
2-nitro-4-chlorobenzeneazo-.beta.-naphthol, 
4-chlorobenzeneazo-3-(2,4-dihydroxy)quinoline, etc.; 
(e) indigo, thioindigo compounds and derivatives thereof such as indigo, 
4,4',6,6'-tetrachloroindigo, 4,4',6'-tribromoindigo, 4,4'-dibromoindigo, 
thioindigo, 5,5'-dichloro-7,7'-dimethylthioindigo, 
5,5'-diethoxythioindogo, etc.; 
(f) aromatic nitro, nitroso compounds and derivatives thereof such as 
2,4-dinitro-4-hydroxydiphenylamine, naphthol green B, 
4,4'-dichloro-2,2'-dinitro-dianilinomethane, etc.; 
(g) phthalocyanine compounds and derivatives thereof such as 
phthalocyanine, copper phthalocyanine, cobalt phthalocyanine, zinc 
phthalocyanine, nickel phthalocyanine, etc.; 
(h) condensates of aromatic hydrocarbons, aromatic amino compounds, 
aromatic nitro compounds or aromatic hydroxy compounds such as m-tolylene 
diamine, 2,4-dinitro-4'-oxydiphenylamine, o-toluidine indophenol, 
.alpha.,.alpha.'-dinitronaphthalene, anthracene, etc. with sodium 
polysulfide or sulfur, conventionally called as sulfur dyes. 
It is very important to recognize in using such a sensitizing substance 
that said sensitizing substance alone can exhibit only very low 
photosensitive activity. For example, there is no photosensitive activity 
exhibited by a suspension having powders of said sensitizing substance 
suspended in an insoluble solvent. Perhaps, this may be due to so called 
concentration quenching phenomenon, although true mechanism remains to be 
elucidated. Therefore, it is necessary to fix said sensitizer in an 
actively dispersed form onto a carrier in order for the sensitizer to 
exhibit its function. 
As described above, the sensitizer for heterogeneous system photosensitive 
oxidation according to the present invention can be prepared by fixing a 
sensitizing substance satisfying the requirements restricted by the 
present invention onto a carrier in an actively dispersed form. The term 
"actively dispersed form" to be used in the present invention is a concept 
obtained inductively from the photosensitive activity represented in terms 
of the aforesaid dissolved oxygen consumption value .DELTA.DO, which is 
required to be at least 0.5, and its precise structure has not yet been 
clarified. Perhaps, it is believed that each substance is dispersed in the 
order of active units which may be molecular or something like that. The 
sensitizing substance is not required to be present necessarily only on 
the surface of the carrier, but it may be present also in the central part 
of the carrier. 
The carrier to be used in the present invention is not particularly limited 
and may include synthetic or natural polymers or modified products thereof 
such as polystyrene, polymethyl methacrylate, polyethylene, polyamide, 
polyacrylonitrile, polyvinylidene chloride, epoxy resin, phenol resin, 
cellulose and the like; inorganic substances such as glass, silica, 
alumina, titanium oxide, zeolite, kaolin, bentonite, etc.; and metals such 
as aluminum, iron, copper, zinc, etc. The carriers may be shaped in 
various forms depending on the intended uses, for example, powders, 
pellets, beads, sheets, films, baloons, foams, fibers, cloths, and others. 
Among the carriers mentioned above, there may be selected suitable class of 
carriers depending on the specific purpose of use of the sensitizer. For 
example, when it is to be used in inhibiting activity of harmful 
organisms, the class of carriers bearing cation groups can advantageously 
be used to provide an improved effect. The cation groups mentioned in the 
present invention are inclusive of substantially dissociated cation groups 
such as 
##STR1## 
and metallic ions M.sup.n+ and also of those having positive charges 
through polarization, although not completely dissociated, such as metal 
oxides, hydroxides, silicates, phosphates, borates, complex salts, etc. 
The carriers satisfying these requirements may be exemplified by the 
following groups (a) to (e). 
(a) carrier originally provided with cation groups: 
anion exchange resin, vinyl pyridine hydrochloride polymer or copolymer, 
dimethylaminoethyl methacrylate hydrochloride polymer or copolymer, 
quaternary ammonium aminocellulose; 
(b) carriers cationized by acid treatment or alkylation treatment of the 
following carriers: 
polyamine-cured epoxy resin, polyamide, melamine resin aminated cellulose, 
vinyl pyridine polymer or copolymer, dimethylamino ethylmethacrylate 
polymer or copolymer, aminopolystyrene polymer or copolymer, etc.; 
(c) carriers modified with the following compounds having cation groups: 
.gamma.-aminopropyl trimethoxysilane hydrochloride, trimethyldodecyl 
ammoniumchloride, triethylstearyl ammoniumchloride, .beta.,.gamma.-epoxy 
propyltrimethyl ammoniumchloride; 
(d) carriers having incorporated metal cation groups by ion-exchange or 
neutralization of the following carriers: sulfonated polystyrene or 
copolymer, acrylic acid polymer or copolymer, natural polymers such as of 
alginic acid, etc. 
(e) carriers having polarized positive charges without ionic dissociation: 
magnesium oxide, titanium oxide, aluminum silicate, calcium silicate, 
barium titanate, silica, alumina, vanadium oxide, etc. 
In another application, wherein the sensitizer of the present invention is 
used for purification of water or air containing impurities, it is 
preferred to use a carrier having an apparent surface area A CO.sub.2 of 
0.1 m.sup.2 /g or more, as measured by the method as hereinafter 
described, for said sensitizer. The present inventors have investigated 
about the relation between an apparent surface area Ax calculated from the 
measured values of adsorption of various gases on the carrier such as 
nitrogen gas, argon gas, helium gas, etc. and its treatment function. As 
the result, a very good relation is found to exist only when carbonic acid 
gas is used as such a gas. It is not yet clear why a carrier having such 
properties bring about improved efficiency in photooxidation treatment. 
Such an increase in efficiency of photooxidation treatment may be 
estimated to be due to the effect of a material to be oxidized adsorbed in 
the vicinity of the carrier or due to the acceleration of the action of a 
sensitizing substance, i.e. photosensitive activity, by such a carrier. 
The apparent surface area A CO.sub.2 herein mentioned is determined by 
measuring the adsorption capacity of carbon dioxide on a carrier using a 
conventionally used gas-adsorption surface area measuring instrument and 
calculating the measured value according to the BET method. Such a 
measuring method is conventionally used in measurement of surface area and 
the measurement can be very easy. The apparent surface area A CO.sub.2 
measured according to the method as mentioned above can be used as a 
parameter indicating photooxidation treatment efficiency of a carrier, as 
evidenced by the especially high efficiency exhibited in all the 
photooxidation treatments by use of carriers having a high value of A 
CO.sub.2 according to the evaluation method. 
Typical examples satisfying such requirements are activated charcoal, 
porous polymer gels of crosslinked polystyrene, crosslinked 
polymethacrylate, crosslinked cellulose, crosslinked nylon or others, 
porous glass, zeolite, molecular sieve, silica gel, activated alumina, 
diatomaceous earth, aluminum silicate, calcium silicate, magnesium 
silicate, oxides or hydroxides of titanium, zirconium, iron, cobalt, 
nickel, copper, magnesium, calcium, zinc, etc., weakly basic, moderately 
basic or strongly basic anion exchange type resins, fibers or membranes 
(among them, OH.sup.- type is especially preferred). The above carrier may 
be used singly or as a combination suitably combined. Furthermore, the 
above carriers may also be dispersed in a matrix. 
The sensitizing substance can be dispersed and fixed on a carrier by any 
method whereby the sensitizing substance can be attached and fixed in an 
actively dispersed form onto the carrier. Depending on the sensitizing 
substance employed and the properties of a carrier, there may be used 
various methods as set forth below. 
(1) A method in which a sensitizing substance is dissolved in an organic 
solvent or an inorganic solvent: 
The sensitizing substance can be adsorbed on a carrier through 
impregnation, adsorption, dispersion or swelling by carrying out such 
procedures as dipping of the carrier in the solution or coating of the 
carrier with the solution. For most of the sensitizing substances as 
mentioned above, this method is applicable. Particularly, when there is 
employed (a) aromatic ketone compound, (b) aromatic heterocyclic compound, 
(c) aromatic hydrocarbon, (d) azo compound, (e) indigo or thioindigo 
compound, (g) phthalocyanine compound, or (h) sulfur dye compound, an 
inorganic solvent such as sulfuric acid, phosphoric acid, nitric acid or 
an aqueous alkali solution may advantageously be used as the solvent and 
the method can be applicable for both organic and inorganic carriers. 
(2) A method wherein a sensitizing substance is blended together with a 
carrier by melting, dissolving or kneading: 
This method is particularly effective when the carrier can be molded under 
a relatively low temperature or when the carrier is an organic substance 
readily soluble in a solvent. After blending, the blend can be shaped in 
any desired form. As one modification of this method, it is also possible 
to dissolve or molecular a sensitizing substance in monomers or 
pre-polymers, followed by completion of post-polymerization. 
(3) A chemical precipitation method in which a sensitive substance is 
formed on a carrier; 
This method is effective when the sensitizing substance is insoluble and 
influsible. The soluble precursor for said sensitizing substance is 
carried on a carrier and then the sensitizing substance is formed by such 
chemical reactions as coupling, condensation, cyclization, etc. This 
method is particularly effective when using as sensitizing substance (a) 
aromatic ketone compound, (b) aromatic heterocyclic compound, (d) azo 
compound, (e) indigo or thioindigo compound, or (g) phthalocyanine 
compound; 
(4) Physical precipitation method such as vapor deposition: 
The sensitizing substance is precipitated physically on a carrier by vapor 
deposition, ion-plating or spattering. Most of the aforesaid sensitizing 
substances are thermally very stable and hence it is particularly 
effective to use this method. As carriers for which this method can be 
used, there may be used any of the carriers as mentioned above, but this 
method is most suitable for metallic materials for which other methods can 
difficultly be applied. 
(5) A method such as vat dyeing or sulfur dyeing in which a sensitizing 
substance insoluble in conventional solvents is made temporarily soluble 
by such a chemical reaction as reduction, supported on a carrier according 
to the method (1) and then returned to the original insoluble state; 
This method is applicable for a sensitizing substance selected from (a) 
aromatic ketone compound, (b) aromatic heterocyclic compound, (e) indigo 
or thioindigo compound and (h) sulfur dye compound. 
In each of the above methods, it is preferred to effect chemical bonding 
between the sensitizing substance and the carrier in order to support the 
sensitizing substance more strongly on the carrier. 
For effecting support of the sensitizing substance on a carrier easily as 
well as firmly, the carrier may be subjected to oxidation, etching, 
treatment with a coupling agent or any other physical or chemical surface 
treatment. 
The amount of a sensitizing substance supported on a carrier may 
sufficiently be very small and it is difficult to show the amount by 
weight. To venture to say, it may sufficiently be such that at least one 
of the color stimulation values, X, Y and Z as determined by JIS Z-8722 is 
80 or less. 
The sensitizer for heterogeneous photo-sensitive oxidation according to the 
present invention can be used in any reaction system of solid-gas phase, 
solid-liquid phase of solid-solid phase optionally selected depending on 
the state of the material to be oxidized under irradiation of light in the 
presence of oxygen or air, whereby the oxidation reaction can proceed with 
good efficiency. As the light source, there may be employed artificial 
light sources including tungsten lamp, fluorescent lamp, halogen lamp, 
metal halide lamp, xenon lamp, etc. There may also be used the sunlight. 
As mentioned above, the sensitizer for heterogeneous system photosensitive 
oxidation of the present invention is obtained by having a sensitizing 
substance excellent in light resistance and oxidation resistance with a 
high photosensitive activity, which has not been known in the prior art, 
incorporated on a carrier. When it is provided for use as a means for 
synthetic chemistry, a means for oxidation treatment, a means for 
modification or a means for other oxidation reaction of various purposes, 
it can maintain its performance stably for a longtime, enabling 
commercially advantageous repeated uses for a long time.

The sensitizer for heterogeneous system photosensitive oxidation of the 
present invention can exhibit noticeable effect for controlling activities 
of organisms when used in the presence of oxygen under exposure to visible 
light. It has not been elucidated so far why the sensitizer of the present 
invention has a remarkable function to control the activities of 
organisms. Such a function, however, is believed to be due to the action 
of singlet oxygen molecule or similar active species which is a molecule 
of oxygen activated by the energy of visible light and said sensitizer. As 
the photosensitive activity of said sensitizer is greater, namely with 
increase in the dissolved oxygen consumption value .DELTA.D0, the effect 
for controlling activities of organisms is better. 
The effect for controlling activities of organisms mentioned in the present 
invention means giving such actions as killing, inhibition or 
proliferation, inhibition of growth, inhibition of germination or 
inactivation of living organisms. As the objective organisms, there may be 
mentioned a wide variety of organisms including viruses, bacteria, molds, 
yeasts, mycoplasmas, algae, plants, insects or others. Thus, the 
sensitizer of the present invention can be used in such fields of uses 
wherein bactericides, fungicides, antiseptic agents, pesticides, 
herbicides, proliferation inhibitors and growth inhibitors are presently 
available. 
When the sensitizer for heterogeneous system photosensitive oxidation of 
the present invention is used for the purpose of controlling the 
activities of organisms, there may be used a light source as mentioned 
above which may suitably be selected depending on the intended uses and 
the forms of objects to be treated. As the oxygen source, pure oxygen is 
of course available, but naturally occurring oxygen, namely oxygen in the 
air or oxygen dissolved in liquids or solids, is enough to achieve the 
object of the present invention. It is also possible as a matter of course 
to supplement oxygen, if desired, by aeration or other methods for further 
improvement of efficiency. 
The salient feature of the method for controlling the activities of 
organisms according to the present invention resides in the fact that its 
effect can be exhibited under completely heterogeneous conditions. 
Referring now to, for example, to the sterilization effect, chemical 
sterilization methods wherein various sterilizers are employed cannot 
effectively be applied, unless said sterilizers are homogeneously 
dissolved or dispersed in the system. Even if said sterilizers may be 
fixed on some carriers, namely by providing some heterogeneous system 
sterilizers, there can be exhibited no effect unless said sterilizers are 
eluted out into the system. To speak more precisely, when said sterilizers 
are completely fixed on the carriers, namely when said sterilizers are 
heterogeneous sterilizers from which no sterilizer is eluted, the 
sterlizing effect is completely lost. The effect of controlling activities 
of organisms possessed by the sensitizer for heterogeneous system 
photosensitive oxidation of the present invention is essentially different 
from the case as mentioned above. That is, the sensitizer per se does not 
possess the effect for controlling the activities of organisms, but such 
an effect is based on activated oxygen molecules formed by the action of 
visible light energy and said sensitizer. Accordingly, there is no 
decrease in its effect even if said sensitizing substance may be 
completely fixed on the carrier. 
Thus, the effect of the sensitizer can permanently be maintained so long as 
said sensitizing substance is not decolored or discolored. As described 
previously in detail, the sensitizer for heterogeneous system 
photosensitive oxidation of the present invention has the physical and 
chemical stability. It is also very important from standpoint of 
environmental pollution that there is no sensitizing substance eluted out 
of the system. On behalf of this specific feature, there will be expected 
applications of the sensitizer of the present invention in infinite scope 
of uses which is not dreamt of in the prior art. 
The light energy source to be used in the present invention may 
sufficiently be a visible light, which is more advantageous in safety as 
compared with radio-active rays or ultra-violet rays. What is more 
important is that a visible light is present universally in the natural 
world. Thus, the method of the present invention has another specific 
feature that no artifical light source equipment is necessary in some 
applications. 
To describe about typical examples of the effect for controlling the 
activities of organisms mentioned in the present invention, they may be 
classified into three categories, depending on the object to be treated 
whether it is (1) gas phase, (2) liquid phase or (3) solid phase. 
When the object to be treated is a gas phase, harmful microorganisms such 
as viruses, bacteria, molds or others floating in, for example, the air 
can be treated. Thus, it is possible to effect sterilization of the air 
which has been deemed as very difficult. To achieve such an object, the 
air can be circulated through a device filled with the sensitizer for 
heterogeneous system photooxidation, which may be shaped in any form 
suitably selected from those as previously described, in the presence of a 
visible light. In some cases, when the sensitizer takes a form in the 
shape of sheets, films, fibers or cloths, it may merely be exposed in the 
air without use of any specific device to exhibit sufficient effect. 
When the object to be treated is a liquid phase, the sensitizer for 
heterogeneous system photo-sensitive oxidation shaped in various forms as 
mentioned above may be suspended, immersed or floated in the liquid to be 
treated in the presence of a visible light, whereby there can be obtained 
such effects as germicidal, fungicidal or proliferation inhibitory effect. 
Thus, there can be effected, for example, sterilization of sewage water, 
sterilization treatments in sea, rivers, lakes or ponds and reservoirs and 
also prevention of abnormal proliferation of mycoplasmas or algae. 
Accordingly, the present method can be very useful as a means for 
purification or re-use of water resources which have been at present great 
social problems and also as a means for prevention of red tide as 
occurring elsewhere in the sea, rivers, lakes or ponds. 
When the object to be treated is a solid phase, preservative effect for 
prevention of decay or generation of molds can be obtained by, for 
example, wrapping foods with a sensitizer for heterogeneous system 
photosensitive oxidation which is shaped in a film. Also, during the 
growth of plants, said sensitizer for heterogeneous system photosensitive 
oxidation can be contacted with the plants, whereby inhibition of the 
plant growth, namely prevention of germination or herbicidal effect can be 
obtained. Furthermore, said sensitizer is useful as a multi-film having 
herbicidal function. 
The method for controlling activities of organisms according to the present 
invention as described above is indeed epoch-making and applicable not 
only in the fields in which chemical substances such as sterilizers have 
been conventionally used, but also in such fields as purification of the 
sea and rivers or prevention of red tide, for which there was no 
applicable prior technique, to great social and industrial advantages. 
In practicing control of organism activities by use of the sensitizers of 
the present invention as inhibitors, said inhibitor (sensitizer) may only 
be placed in the living circle of organisms in the presence of a visible 
light and oxygen. For better understanding, reference is made to the 
simplest embodiment of the invention as shown in FIG. 4, wherein the inner 
wall of the water tank 1 is coated with the inhibitor 2 of the present 
invention. In such a water tank, there is introduced a liquid to be 
treated 3 containing living organisms and said liquid is exposed to 
irradiation of a visible light such as the sunlight from outside in the 
presence of oxygen, whereby the activities of organisms in the liquid to 
be treated 3 can be controlled. To mention one example, by application of 
a coating as shown in FIG. 4 in an outdoor pool, sterilization of the 
pooled water can effectively be conducted. FIG. 5 shows inhibitors 2 in 
the form of beads filled in a vessel 4 which can be contacted with the 
external air. Any desired number of such filler beds can be arranged in 
the air under irradiation of a visible light to thereby perform effective 
sterilization of the air. FIG. 6 shows plural number of such filler beds 
suspended and immersed in the water bath 1. In this case, the filler beds 
may be replaced by inhibitors in the shape of cloths, tapes or nets. As 
one modification of the embodiment as shown in FIG. 6, the inhibitors of 
the present invention may only be located in natural water resources such 
as sea or lakes, whereby it is possible to prevent, for example, abnormal 
generation of red tide. FIG. 7 shows one example of a device capable of 
treating continuously a liquid to be treated (light source not shown). The 
inhibitor part 4 (e.g. filler bed as shown in FIG. 5) containing 
inhibitors is arranged in the vessel having inlet and outlet portions and 
the liquid to be treated is passed through the vessel in the direction of 
the arrow to effect treatment. In this case, the light source may be 
provided internally of the vessel, or alternatively the vessel may be made 
transparent to permit irradiation of light from outside. The oxygen may 
sometimes be sufficiently that dissolved in the liquid to be treated, but 
it is also possible to add oxygen compulsorily by aeration, etc. 
As described above, the device to be used for practicing the method of the 
present invention may have a very simple constitution, comprising an 
inhibitor part containing the aforesaid inhibitors arranged so as to be 
contactable with the living circle of organisms to be treated and a means 
for irradiating a visible light arranged so as to be capable of 
irradiating said inhibitor part. 
As mentiond above, the sensitizer for heterogeneous system photosensitive 
oxidation to be used for treatment of harmful organisms may preferably be 
prepared by supporting a sensitizer substance on a carrier having cation 
groups. Such a sensitizer is found to have a specific property to adsorb a 
large amount of organisms thereon. By use of such a sensitizer as 
adsorbent, water or air containing harmful organisms can only be contacted 
with said sensitizer to remove a part or all of the harmful organisms 
through adsorption even in the absence of a visible light. Under 
irradiation of a visible light in the presence of oxygen, the adsorbed 
organisms can be inactivated even to the extent of being killed. Thus, 
according to another embodiment of the method for treatment of harmful 
organisms by use of the sensitizer for heterogeneous system photosensitive 
oxidation of the present invention, a system containing such organisms is 
subjected to adsorption of the organisms on the sensitizer in the first 
step and then, on depletion of the adsorption activity, the sensitizer 
having organisms adsorbed thereon is activated by treatment with 
irradiation of light in the presence of air or oxygen. By use of the two 
step process as mentioned above, the sensitizer activated in the second 
step treatment can be used again in the first step. Accordingly, by 
repeating alternately the two steps combined, there can be established an 
entirely novel process for treatment of harmful organisms. The first 
specific feature of this process resides in enabling treatment of harmful 
organisms in places on which no irradiation of light is possible. The 
second feature resides in surprisingly high efficiency of the treatment. 
The third feature resides in that the sunlight may be made readily 
available as the visible light source, because the first step may be 
conducted at night or when it is rainy, while the second step can be 
performed in the day time, whereby continuous treatments through day and 
night can be made possible. 
Another important field in which the sensitizer for heterogeneous 
photosensitive oxidation of the present invention can be applied is 
purification of water or air containing impurities. By use of the 
sensitizer of the present invention, highly efficient purification 
treatments are possible in purifying sewage water or industrial 
wastewater, making harmful substances harmless by oxidation, deodorizing 
substances with offensive odor or decoloration of colored substances. 
Examples of the contaminating substances, harmful substances or substances 
with offensive odor which can be removed by such treatments are organic 
compounds including olefinic compounds, diene type compounds polyene type 
compounds, aromatic compounds, heterocyclic compounds, alcohols, glycolic 
compounds, amine compounds, amide compounds, urea compounds, urethane 
compounds, phenol compounds, nitrile compounds, ketone compounds, ester 
compounds, aldehyde compounds, sulfur-containing compounds, etc., 
inorganic compounds including cyanate compounds, thiocyanate compounds, 
sulfite compounds, sulfide compound, thiosulfate compounds, etc. 
Furthermore, there are animal or vegetable wastes principally composed of 
protein compounds, carbohydrates compounds or fatty compounds of which 
structures cannot be identified, or decomposed products thereof. In 
carrying out purification of water or air containing these impurities by 
use of the sensitizer of the present invention, there may be used the same 
procedure and conditions as described previously with reference to the 
treatment of water or air containing harmful organisms. 
The present invention is further illustrated with reference to the 
following Examples and Comparative examples, in which all parts and 
percentages are by weight unless otherwise noted. 
Measurement of electron spectrum was conducted using Hitachi-124 Model 
spectrophotometer, the measurement of dissolved oxygen amount using 
Dissolved oxygen meter DO-1B Model (Toa Denpa Kogyo Co., Ltd.), and 
measurement of surface area using Surface area measuring instrument P-850 
Model (Shibata Kagaku Co., Ltd.). 
TEST METHODS 
(A) Measurement of dissolved oxygen consumption value 
(1) A sensitizing substance (5 mg) is supported on 50 mg of styrene-divinyl 
benzene copolymer (weight ratio=9:1) beads with particle diameters of 0.1 
mm to 0.5 mm, which is in turn suspended in 500 ml of distilled water to 
be provided as a sample for measurement. Supporting of the sensitizing 
substance is performed according to any one of the methods as described in 
the specification. 
(2) Light source 
Using 500 W xenon lamp as light source, the luminosity at the light 
receiving face of the measuring vessel is set at 5,000 luxes by the 
standard white light having adjusted spectrum distribution by the filter 
as determined by JIS Z-8902. 
(3) Measuring vessel 
There is used a square vessel made of pyrex of 100 mm.times.100 mm.times.50 
mm with only the light receiving face of 100 mm.times.100 mm being made 
transparent, other faces being intrasparent in dark color. 
(4) Measuring method 
In a darkroom, 5 g of furfuryl alcohol was dissolved in the amount of the 
sample as determined in (1) and the dissolved oxygen value before the 
reaction DO.sub.0 is set at 8 ppm at a temperature of 20.degree. C. Said 
sample is filled in the measuring vessel of (3), followed by sealing. 
Under stirring with a magnetic stirrer, irradiation is effected from the 
light source of (2) for 10 minutes. 
After irradiation, the dissolved oxygen value DO.sub.1 is measured and the 
dissolved oxygen consumption value is calculated by the following formula: 
##EQU2## 
wherein DO.sub.0= 8 ppm. 
(B) Light resistance evaluation of sensitizing substance 
A cotton cloth is used as carrier and evaluation is conducted according to 
JISL-0841 by the direct sunshine method, the first light exposure method. 
(C) Measurement of apparent surface area A CO.sub.2 
There is used a commercially available surface area measuring instrument 
according to the gas adsorption method, but carbon dioxide is used as the 
gas. By means of the above measuring instrument, Vm value is measured and 
the apparent surface area A CO.sub.2 is calculated from the following 
formula: 
##EQU3## 
wherein a is the cross-sectional area of carbon dioxide molecule 
(.ANG..sup.2) and Vm is volume of carbon dioxide adsorbed (ml). 
EXAMPLE 1 
Preparation of various sensitizers for heterogeneous system photosensitive 
oxidation 
(1) Each 5 mg of the compounds shown in Table 1 was dissolved in 25 g of 
xylene and mixed with 50 g of the aforesaid polystyrene beads. After 
drying under vacuum at 100.degree. C. for 10 hours, the mixture was 
suspended in 500 ml of distilled water for measurement of the dissolvved 
oxygen consumption value .DELTA.DO. The results are set forth in Table 4 
together with the test values of light resistance and the results of 
.lambda..sub.max measured. 
(2) Each 5 mg of the compounds shown in Table 2 was dissolved in 50 g of 
98% conc. sulfuric acid and mixed with 50 g of the aforesaid polystyrene 
beads. After standing at 40.degree. C. for 24 hours, each mixture was 
thrown into water, washed with an alkali and then with water, and 
suspended in 500 ml of distilled water for measurement of the dissolved 
oxygen consumption value .DELTA.DO. The results are set forth in Table 4 
together with the light resistance values and the results of 
.lambda..sub.max measured. 
(3) Each 5 mg of the compounds shown in Table 3, 0.5 g of caustic soda and 
0.5 g of hydrosulfite were dissolved in 30 ml of distilled water and the 
resultant solution was subjected previously to sulfonation treatment with 
98% conc. sulfuric acid at 40.degree. C. for 24 hours. Each solution was 
then mixed with 50 g of the aforesaid polystyrene beads. After standing at 
40.degree. C. for 24 hours, each mixture was thrown into water for washing 
and then suspended in 500 ml of distilled water for measurement of 
dissolved oxygen consumption value .DELTA.DO. The results are shown in 
Table 4 together with light resistance values and the results of 
.lambda..sub.max measured. 
TABLE 1 
______________________________________ 
Compound No. 
Name of compounds 
______________________________________ 
No. 1 1-hydroxy-4-aminoanthraquinone 
No. 2 N,N'--dibenzoyl-1,4-diaminoanthraquinone 
No. 3 2,4-dinitro-4'-hydroxy diphenylamine 
No. 4 4-nitrobenzeneazo-4'-aminobenzene 
No. 5 N--methyl-1,4-diaminoanthraquinone 
No. 6 coronene 
No. 7 2-methylbenzeneazo-.beta.-naphthylamine 
______________________________________ 
TABLE 2 
______________________________________ 
Compound No. Name of compounds 
______________________________________ 
No. 8 2,2'-diphenylanthraquinone dithiazole 
No. 9 dibenzopyrenequinone 
No. 10 dibromopyranthrone 
No. 11 5,5'-dichloro-7,7'-dimethylthioindigo 
No. 12 dibromo-iso-violanthrone 
No. 13 dihydroanthraquinazine 
No. 14 flavanthrone 
No. 15 N--benzoyl-4-aminoanthrapyrimidine 
No. 16 phthalocyanine 
No. 17 copper-phthalocyanine 
No. 18 octachloro-copper-phthalocyanine 
No. 19 2-chloro-4-nitrobenzeneazo-.beta.-naphthol 
No. 20 2,4-dinitrobenzeneazo-.beta.-naphthol 
______________________________________ 
TABLE 3 
______________________________________ 
Compound No. Name of compounds 
______________________________________ 
No. 21 dibromo-dibenzopyrenequinone 
No. 22 dibromo-anthanthrone 
No. 23 5,5'-benzamidoanthraquinone carbazole 
No. 24 indigo 
No. 25 pyranthrone 
No. 26 4-methyl-5,7-dichloro-4'-methyl-6- 
chloro-thioindigo 
No. 27 violanthrone 
______________________________________ 
TABLE 4 
______________________________________ 
Light resistance 
Compound No. 
.DELTA.DO value 
test values .lambda..sub.max(nm) 
______________________________________ 
No. 1 4.9 6 524 
No. 2 25.0 7 538 
No. 3 4.1 6 420 
No. 4 3.6 6 444 
No. 5 2.8 6 586 
No. 6 7.8 4 410 
No. 7 4.1 5 439 
No. 8 58.4 4 431 
No. 9 82.0 6 464 
No. 10 96.0 7 504 
No. 11 88.0 6 538 
No. 12 90.2 7 590 
No. 13 4.3 7 556 
No. 14 3.7 6 431 
No. 15 2.9 6 427 
No. 16 32.0 8 610 
No. 17 41.3 8 616 
No. 18 52.3 8 680 
No. 19 21.0 7 553 
No. 20 24.3 7 467 
No. 21 89.9 7 471 
No. 22 78.3 8 453 
No. 23 21.0 6 462 
No. 24 4.3 5 599 
No. 25 90.3 6 474 
No. 26 92.3 5 541 
No. 27 44.0 7 599 
______________________________________ 
EXAMPLE 2 
The compound No. 9 dibenzopyrenequinone used in Example 1, 100 mg, was 
dissolved in 100 g of 98% conc. sulfuric acid and then mixed with 100 g of 
styrene-methyl methacrylate-divinylbenzene copolymer beads (weight 
ratio=10:1:1) with average particle diameter of 0.3 mm. After standing for 
one hour at 40.degree. C., the mixture was thrown into water, followed by 
washing with an alkali and with water, to prepare a sensitizer for 
heterogeneous system photosensitive oxidation. The sensitizer was 
suspended in 1.2 liter of distilled water containing 4.0 g of furfuryl 
alcohol and the reaction was carried out under oxygen atmosphere using an 
inner-irradiation type photochemical reactor (light source: 400 W 
sun-light lamp, produced by Toshiba Electric Co., Ltd.). The quantity of 
furfuryl alcohol disappeared was measured by gas chromatography 
(Hitachi-163 Model gaschromatograph) to obtain the result shown in Table 
5. 
TABLE 5 
______________________________________ 
Time of irradiation: 
5 10 15 20 
(min.) 
Quantity disappeared: 
22 51 73 91 
(%) 
______________________________________ 
COMATIVE EXAMPLE 1 
One hundred milligrams (100 mg) of the dibenzopyrenequinone powders used in 
Example 2 were suspended in 1.2 liter of distilled water containing 40 g 
of furfuryl alcohol and the reaction was carried out in the same reactor 
as used in Example 2. After irradiation for 5 minutes, 10 minutes, 15 
minutes and 20 minutes, there was substantially no furfuryl alcohol 
disappeared. 
EXAMPLE 3 
The compound No. 22 dibromo-anthanthrone used in Exampe 1 (100 mg) was 
dissolved in 200 ml of distilled water containing 1 g of caustic soda and 
1 g of hydrosulfite. A strip of a white cotton cloth of 300 mm.times.300 
mm (kanakin No. 3) was dipped in the resultant solution at 40.degree. C. 
and left to stand for one hour. After said immersion, the cloth was taken 
out and left to stand in the air for one hour, followed by washing with 
water, to obtain a sensitizer for heterogeneous system photosensitive 
oxidation. 
The sensitizer was immersed in the reactor employed in Example 2 and the 
reaction was carried out under the same conditions. The rate of furfuryl 
alcohol disappeared was as shown in Table 6. 
TABLE 6 
______________________________________ 
Irradiation time (min.) 
5 10 15 20 
Quantity disappeared (%) 
19 47 66 81 
______________________________________ 
EXAMPLE 4 
The compound No. 2 N,N'-dibenzoyl-1,4-diaminoanthraquinone (500 mg) used in 
Example 1 was dissolved in 100 ml of acetone and mixed with 100 g of 
100-mesh silica gel powders. After standing for one hour, the mixture was 
thrown into water for washing to prepare a sensitizer for heterogeneous 
system photosensitive oxidation. 
Using the same reactor and the reaction conditions as used in Example 2, 
the reaction was carried out, whereby the rate of furfuryl alcohol 
disappeared was as shown in Table 7. 
TABLE 7 
______________________________________ 
Irradiation time (min.) 
5 10 15 20 
Quantity disappeared (%) 
7 12 18 23 
______________________________________ 
EXAMPLE 5 
In 300 ml of water were dissolved 7.2 g of .beta.-naphthol and 1.8 g of 
caustic soda and a strip of cotton cloth (300 mm.times.300 mm, Kanakin No. 
3) was immersed in the resultant solution for 10 minutes. The above cotton 
cloth was dipped for 30 minutes in a solution of 0.75 g of 
2-chloro-4-nitroaniline, 1.0 g of 35% hydrochloric acid and 0.5 g of 
sodium nitrite dissolved (at 10.degree. C.) in 100 ml of water. After 
dipping, the cloth was thoroughly washed with water to prepare a 
sensitizer for heterogenous system photosensitive oxidation containing 
2-chloro-4-nitrobenzeneazo-.beta.-naphthol carried on a carrier. 
The sensitizer was dipped in the same reactor as used in Example 2 to carry 
out the reaction under the same conditions. The rate of furfuryl alcohol 
disappeared was as shown in Table 8. 
TABLE 8 
______________________________________ 
Irradiation time (min.): 
5 10 15 20 
Quantity disappeared (%): 
5 12 19 25 
______________________________________ 
EXAMPLE 6 
The sensitizer for heterogeneous system photosensitive oxidation used in 
Example 2 was recovered and, after washing with water, suspended in 1.2 
liter of distilled water. The suspension was charged into the same reactor 
as used in Example 2 and irradiation was continued for 24 hours under 
oxygen atmosphere. There was no change detected in appearance in the 
sensitizer recovered after the irradiation. The sensitizer recovered was 
further suspended in distilled water containing 4.0 g of furfuryl alcohol 
and the reaction was carried out using the same reactor. The rate of 
furfuryl alcohol disappeared was as shown in Table 9. 
COMATIVE EXAMPLE 2 
A solution of 100 mg of Rose Bengal (light resistance test value=1) 
dissolved in 250 ml of distilled water was mixed with 100 g of 
ion-exchange resins (IRA-400; Rohm & Haas Co.) and the mixture was left to 
stand at room temperature for 24 hours. 
After thorough washing of the mixture with water, there was prepared a 
sensitizer for heterogeneous system photosensitive oxidation. Using this 
sensitizer, the same procedure as in Example 6 was repeated whereby there 
was observed a noticeable discoloration after 24 hours of irradiation. In 
the experiment subsequently conducted, the rate of furfuryl alcohol 
disappeared was as shown in Table 9. 
COMATIVE EXAMPLE 3 
Comparative example 2 was repeated except that Rose Bengal was changed to 
Methylene Blue (light resistance test value=3) and the ion-exchange resins 
IRA-400 to IRC-200 (Rohm & Haas Co.). There was also a noticeable 
discoloration after 24 hours of irradiation and the rate of furfuryl 
alcohol disappeared in the experiment subsequently conducted was as shown 
in Table 9. 
TABLE 9 
______________________________________ 
Irradiation time (min.): 
5 10 15 20 
______________________________________ 
Quantity 
Example 6 23 53 71 93 
dis- Comparative 1.5 2.2 3.1 3.9 
appeared 
example 2 
(%) Comparative 2.1 2.9 3.7 4.0 
example 3 
______________________________________ 
EXAMPLE 7 
A solution of 100 mg of the compound No. 11, 5,5'-dichloro-7,7'-dimethyl 
thioindigo used in Example 1 dissolved in 100 g of 98% conc. sulfuric acid 
was mixed with 100 g of styrene-methyl methacrylate-divinyl benzene 
copolymer beads (weight ratio=10:1:1) with average particle diameter of 
0.3 mm. After standing at 40.degree. C. for one hour, the mixture was 
thrown into water and washed with an alkali and with water to prepare a 
sensitizer for heterogeneous system photosensitive oxidation. The 
sensitizer was suspended in 1.2 liter of water containing 50 ppm of 
p-cresol and the reaction was carried out by charging said suspension into 
the same reactor as used in Example 2. The residual amount of p-cresol 
with the reaction was as shown in Table 10. 
TABLE 10 
______________________________________ 
Irradiation time (min.): 
10 20 30 40 
Residual amount (ppm): 
31 20 11 3 
______________________________________ 
After 40 minutes, the reaction mixture was filtered to give a filtrate 
which is completely colorless and transparent, indicating no change in 
appearance of the sensitizer for heterogeneous system photosensitive 
oxidation. 
EXAMPLE 8 
One gram of 1,4-diaminoanthraquinone was dissolved in 50 g of 
dimethylformamide and 5 g of acroyl chloride was added thereto. After the 
reaction at 30.degree. C. for 5 hours, the reaction mixture was thrown 
into water and the precipitates were filtered and washed to give 
N,N'-diacroyl-1,4-diaminoanthraquinone. Five milligrams (5 mg) of this 
product were weighed and dissolved by mixing with 45 g of styrene, 5 g of 
divinylbenzene and 0.5 g of benzoyl peroxide. The resultant solution was 
subjected to suspension polymerization in 0.5% aqueous polyvinyl alcohol 
solution at 70.degree. C. for 24 hours to give a copolymer in the form of 
beads with diameters from 0.1 mm to 0.5 mm at a yield of 100%. This 
sensitizer was found to have a .DELTA.DO value of 19.0, a light resistance 
test value of 6 and .lambda..sub.max of 529 nm. 
EXAMPLE 9 
In a glass tube were sealed 25 g of anthracene and 12.5 g of sulfur powders 
and the reaction was carried out at 300.degree. C. for 5 hours to give an 
olive-colored product. The product (5 mg) was dissolved in 30 ml of 
distilled water containing 0.5 g of caustic soda, 0.2 g of sodium sulfide 
and 0.3 g of hydrosulfite. The resultant solution was mixed with 50 g of 
styrene-divinylbenzene copolymer beads (weight ratio=9:1) with diameters 
of 0.1 mm to 0.5 mm which had been subjected to sulfonation treatment at 
40.degree. C. for 24 hours, and the mixture was left to stand in the air 
at 40.degree. C. for 24 hours. After washing with water, there was 
obtained a sensitizer for heterogeneous system photosensitive oxidation. 
The sensitizer is found to have a .DELTA.DO value of 58.3, a light 
resistance test value of 6 and .lambda..sub.max of 611 nm. 
EXAMPLE 10 
The compound No. 17 copper-phthalocyanine (100 mg) was supported by vapor 
deposition on an aluminum foil of 200 mm.times.200 mm.times.0.020 mm to 
prepare a sensitizer for heterogeneous system photosensitive oxidation 
colored in blue on its surface. This sensitizer was immersed in the same 
reactor as used in Example 2 to carry out the reaction under the same 
conditions. The rate of furfuryl alcohol disappeared was as shown in Table 
11. 
TABLE 11 
______________________________________ 
Irradiation time (min.): 
5 10 15 20 
Quantity disappeared (%): 
11 18 27 36 
______________________________________ 
EXAMPLE 11 
The sensitizer for heterogeneous system photosensitive oxidation containing 
the compound No. 9 dibenzopyrenequinone prepared in Example 2 (10 g) was 
suspended in one liter of water containing 3.5.times.10.sup.5 cells/ml of 
a Gram-negative microorganism (Escherichia coli IFO-3301) and the standard 
white light of 3,500 luxes was irradiated over the water surface for 3 
hours. The residual living microorganism during said irradiation were 
measured by the agar plate cultivation method to give the results as shown 
in FIG. 1(a), which shows a remarkable sterilizing effect. 
COMATIVE EXAMPLE 4 
Example 11 was repeated except that the compound No. 9 dibenzopyrenequinone 
(100 mg) was omitted. The results were also shown in FIG. 1(a). 
EXAMPLE 12 
A mixture comprising 50 g of styrene, 50 g of divinylbenzene, 100 g of 
4-vinyl pyridine and 1 g of azobisisobutyronitrile was suspended in 800 ml 
of an aqueous 0.5% polyvinyl alcohol solution and polymerized at 
65.degree. C. for 10 hours to give a polymer in the form of beads with 
average diameter of 0.25 mm. The polymer beads were treated with a 6N 
sulfuric acid at room temperature for 6 hours. Then, into 100 g of 98% 
sulfuric acid containing 100 mg of the compound No. 10 dibromopyranthrone 
used in Example 1 dissolved therein, the aforesaid polymer beads were 
added. The mixture was left to stand at 40.degree. C. for 24 hours, 
followed by washing with water, to prepare a sensitizer for heterogeneous 
system photosensitive oxidation having cation groups. 
The above sensitizer for heterogeneous system photosensitive oxidation (10 
g) was suspended in one liter of water containing 2.2.times.10.sup.5 /ml 
of a Gram-negative microorganism (Escherichia coli IFO-3301) and the 
standard white light of 3,500 luxes was irradiated over the water surface 
for 3 hours. The residual living microorganisms during said irradiation 
were measured similarly as in Example 11 to give the results as shown in 
FIG. 1(1). 
COMATIVE EXAMPLE 5 
Example 12 was repeated except that there was used no compound No. 23 
dibromopyranthrone. The results are also shown in FIG. 1(b). 
EXAMPLE 13 
A strip of a commercially available 6-Nylon cloth (N-1003) of 300 
mm.times.300 mm was immersed in an aqueous 25% sulfuric acid solution at 
25.degree. C. for 15 minutes, then washed with water and dried. 
The compound No. 12 dibromo-iso-violanthrone used in Example 1 (150 mg) was 
dissolved in 200 ml of distilled water containing 1 g of caustic soda and 
1 g of hydrosulfite. In the resultant solution was dipped the above 
6-nylon cloth subjected to sulfuric acid treatment at 40.degree. C. for 
one hour. The cloth was taken out after said dipping and left to stand in 
the air for one hour, followed by washing with water, to obtain a 
sensitizer for heterogeneous system photosensitive oxidation having cation 
groups. The sensitizer was suspended in one liter of water containing 
9.7.times.10.sup.7 /ml of a Gram-negative microorganism (Escherichia coli 
IFO-3301) and the standard white light of 3,500 luxes was irradiated over 
the water surface. The changes in number of residual living organisms were 
measured similarly as in Example 11 to obtain the results shown in Table 
12. 
EXAMPLE 14 
Example 13 was repeated except that 10 g of commercially available 
ion-exchange resins (Amberlite IRA-938: anion exchange resins, produced by 
Rohm & Haas Co.) was used as carrier in place of the 6-nylon cloth 
subjected to the sulfuric acid treatment. The results are also shown in 
Table 12. 
EXAMPLE 15 
Example 13 was repeated except that 10 g of of aluminum silicate (400-mesh) 
was used as carrier in place of the 6-nylon cloth subjected to the 
sulfuric acid treatment. The results are also shown in Table 12. 
COMATIVE EXAMPLE 6 
A mixture comprising 50 g of styrene, 50 g of divinylbenzene, 100 g of 
p-chloromethyl stryene and 1 g of azobisisobutyronitrile was subjected to 
suspension polymerization in 800 ml of an aqueous 0.5% polyvinyl alcohol 
solution at 70.degree. C. for 24 hours to obtain polymer beads with 
average diameter of 0.15 mm. The polymer beads (100 g) and 10 g of Rose 
Bengal were mixed with 500 ml of dimethylformamide and the reaction was 
conducted under heating at 60.degree. C. for 48 hours. After the reaction, 
filtration and washing with water were repeated to give a sensitizer for 
heterogeneous system photosensitive oxidation. Using `0 g of this 
sensitizer, evaluation of its performance was conducted under the same 
conditions as in Example 13 to obtain the results as shown in Table 12. 
COMATIVE EXAMPLE 7 
One mg of a commercially available sterilizer mono-sodium 
dichloroisocyanurate was dissolved in one liter of water containing 
9.7.times.10.sup.4 /ml of a Gram-negative microorganism (Escherichia coli 
IFO-3301) (concentration of the sterilizer=1 ppm). The changes in number 
of the living microorganism were measured by the same method as in Example 
11 to give the results as shown in Table 12. 
TABLE 12 
______________________________________ 
0 minute 30 minutes 
60 minutes 
______________________________________ 
Example 13 
9.7 .times. 10.sup.4 /ml 
0/ml 0/ml 
Example 14 
9.7 .times. 10.sup.4 /ml 
2/ml 0/ml 
Example 1.5 
9.7 .times. 10.sup.4 /ml 
5/ml 0/ml 
Comparative 
9.7 .times. 10.sup.4 /ml 
5 .times. 10.sup.2 /ml 
125/ml 
example 6 
Comparative 
9.7 .times. 10.sup.4 /ml 
3 .times. 10.sup.2 /ml 
271/ml 
example 7 
______________________________________ 
EXAMPLE 16 
The sensitizer for heterogeneous system photosensitive oxidation employed 
in Example 12 (10 g) was suspended in one liter of a culture broth for 
algae (ASP-2) containing bluish algae and diatom and the suspension was 
left to stand in the outdoors under aeration with an air adjusted to 
contain 1% of carbon dioxide. After one month, there was observed no 
proliferation of algae at all. 
COMATIVE EXAMPLE 8 
Example 16 was repeated except that no dibromopyranthrone (100 mg) was 
used. After one week, there was observed noticeable proliferation of 
algae. 
EXAMPLE 17 
The sensitizer for heterogeneous system photosensitive oxidation as 
prepared in Example 8 (10 g) was suspended in one liter of water 
containing 2.2.times.10.sup.5 /ml of a mold (Trichoderma viride IFO-4847) 
and the standard white light of 3,500 luxes was irradiated over the water 
surface for 3 hours. The residual living microorganism cells were measured 
similarly as in Example 11 to obtain the results as shown in FIG. 2. 
COMATIVE EXAMPLE 9 
Example 17 was repeated except that the sensitizer contained no 
N,N'-diacroyl-1,4-diaminoanthraquinone to obtain the results as shown in 
FIG. 2. 
EXAMPLE 18 
The sensitizer for heterogeneous system photosensitive oxidation as 
prepared in Example 3 was dipped in one liter of water containing 
1.9.times.10.sup.5 /ml of yeast (Candida albicans IFO-0583) and irradiated 
with light similarly as in Example 11. The number of residual living 
microorganisms was measured in the same manner as in Example 11 to obtain 
the results as shown in FIG. 3. 
COMATIVE EXAMPLE 10 
Example 18 was repeated except that there was used no dibromo-anthanthrone 
to obtain the results as shown in FIG. 3. 
EXAMPLE 19 
The compound No. 2 N,N'-dibenzoyl-1,4-diaminoanthraquinone (1.5 g) used in 
Example 1 was dissolved in 100 g of a commercially available acrylic clear 
lacquer. The solution was coated on a commercially available ply-wood (300 
mm.times.300 mm.times.3 mm) to obtain a coated film colored in reddish 
violet. One platinum loop of a mold (Trichoderma viride IFO-4847) was 
dispersed in 100 ml of a culture broth for mold. The resultant dispersion 
was applied by a micropipette on four spots on the above coated film at 
intervals of 100 mm. This sample was left to stand for 7 days in a 
thermostatical humidistat maintained at a temperature of 30.degree. C. and 
a humidity of 85% under a luminosity on the sample surface set at 350 
luxes. The periodical changes are as shown in Table 13. 
COMATIVE EXAMPLE 11 
Example 19 was repeated except that N,N'-dibenzoyl-1,4-diaminoanthraquinone 
was omitted to give the results as shown in Table 13. 
TABLE 13 
______________________________________ 
2 days 3 days 5 days 7 days 
______________________________________ 
Example 19 
no change no change no change 
no change 
Comparative 
black spot 
black vigorous 
vigorous 
example 11 
partly spots prolife- 
prolife- 
formed formed ration ration 
______________________________________ 
EXAMPLE 20 
In 100 g of 98% of conc. sulfuric acid was dissolved 250 mg of the compound 
No. 11, 5,5'-dichloro-7,7'-dimethyl thioindigo as used in Example 1. The 
resultant solution was mixed with 100 g of a styrenemethyl 
methacrylate-divinylbenzene copolymer beads (weight ratio=10:1:1) with 
average particle diameter of 0.1 mm, and the mixture was left to stand at 
40.degree. C. for one hour. Then, the mixture was thrown into water, 
followed by washing with an alkali and with water, to obtain a sensitizer 
for heterogeneous system photosensitive oxidation. 
A ground with an area of 2 m.times.2 m was divided into two areas of 2 
m.times.1 m. Over one of the divided areas, there was sprayed the total 
amount of the above sensitizer for heterogeneous system photosensitive 
oxidation. After two months, there was abundant growth of weeds in the 
non-sprayed area, while there was no growth of weeds in the sprayed area 
at all. 
EXAMPLE 21 
The same sensitizer for heterogenous system photosensitive oxidation as 
used in Example 20 was suspended in an amount of 50 g in one liter of a 
pooled water containing mosquito larvae (Culex tritaeniorhynchus) and the 
suspension was left to stand in a room set at a luminosity on the water 
surface of 750 luxes. The percentages of the survived larvae and of the 
hatched larvae, respectively, are as shown in Table 14. 
COMATIVE EXAMPLE 12 
Example 21 was repeated except that 250 mg of 5,5'-dichloro-7,7'-dimethyl 
thioindigo was not used, whereby the results shown in Table 14 were 
obtained. 
TABLE 14 
______________________________________ 
Percentage of survival (%) 
Percentage 
1 day 3 days 7 days hatched (%) 
______________________________________ 
Example 21 
28 4 0 0 
Comparative 
95 93 93 88 
example 12 
______________________________________ 
EXAMPLE 22 
In 200 ml of distilled water containing 1 g of caustic soda and 1 g of 
hydrosulfite, 250 mg of the compound No. 25 pyranthrone was dissolved. In 
the resultant solution was immersed a commercially available cellophane 
film of 300 mm.times.300 mm (no treatment; thickness=15.mu.) at 40.degree. 
C. for one hour. The cellophane film was taken out after said immersion 
and left to stand in the air for one hour, followed by washing with water, 
to obtain a sensitizer for heterogeneous system photosensitive oxidation. 
Using this film, meat was wrapped therein. The wrapped meat was left to 
stand under the conditions of 30.degree. C. and a luminosity of 350 luxes 
for one week to obtain the results as shown in Table 15. 
COMATIVE EXAMPLE 13 
Example 22 was repeated except that 250 mg of pyranthrone was not used to 
obtain the results as shown in Table 15. 
TABLE 15 
______________________________________ 
After one day 
After 7 days 
______________________________________ 
Example 22 no change no change 
Comparative example 13 
putrid smell 
excessive 
formed putrid smell 
______________________________________ 
EXAMPLE 23 
A commercially available polystyrene film (thickness=50.mu.) was dipped in 
a mixture for crosslinking comprising para-formaldehyde, acetic acid and 
sulfuric acid (5 parts:25 parts:70 parts) and crosslinking reaction was 
effected at 75.degree. C. for 3 hours to crosslink the polystyrene to make 
it insoluble. Then, the crosslinked film was dipped in a solution 
comprising chloromethyl ether and stannic chloride (85:15) to carry out 
the reaction at 40.degree. C. for one hour and 20 minutes. After the 
reaction, the product was washed with 10% hydrochloric acid, distilled 
water and acetone. The thus chloromethylated film was aminated at 
40.degree. C. for one hour and 20 minutes by dipping in a 30% aqueous 
trimethylamine solution. Subsequently, 0.5 part of the compound No. 2 
N,N'-dibenzoyl-1,4-diaminoanthraquinone was dissolved in 50 parts of 
acetone. The above treated film was dipped in the resultant solution and 
left to stand at 40.degree. C. for 10 hours, followed by drying on the 
air, to obtain a sensitizer carried on a carrier having cation groups. 
Five sheets of the above film sensitizer (1 m.times.2 m) were immersed 
vertically into a water storage tank of 15 m.times.10 m with the depth of 
2.5 m. They were left to be immersed in the tank during the night and 
taken out from the tank for exposure to the sunlight in the day time under 
the sunshine. This procedure was repeated continuously for 20 days. 
Sampling of the stored water was performed once per day for measurement of 
miscellaneous microorganism cells by the agar culture method. The results 
are shown in Table 16. 
COMATIVE EXAMPLE 14 
Example 23 was repeated, but there was employed a film prepared according 
to the same method as in Example 23 except for using no N,N'-dibenzoyl 
diaminoanthraquinone. The results are also shown in Table 16. 
TABLE 16 
______________________________________ 
Microorganism cells in the water tested 
(cells/ml) 
1st day 3rd day 5th day 7th day 
10th day 
______________________________________ 
Example 5 1 0 2 0 
23 
Compara- 
5 .times. 10.sup.2 
3 .times. 10.sup.2 
4 .times. 10.sup.2 
7 .times. 10.sup.2 
8 .times. 10.sup.2 
tive ex- 
ample 14 
______________________________________ 
EXAMPLE 24 
In 200 parts of distilled water containing 1 part of caustic soda and 1 
part of hydrosulfite was dissolved 0.1 part of the compound No. 23 
dibromodibenzopyrenequinone as used in Example 1. A white cotton cloth 
(Kanakin No. 3) was dipped in the resultant solution and left to stand at 
40.degree. C. for one hour. After dipping, the cloth was taken out and 
left to stand in the air for one hour. Then, the cloth was washed with 
water and dried on air. The thus treated cloth was further immersed in an 
aqueous 10% .beta.-.gamma. epoxypropyl trimethylammonium chloride solution 
at 35.degree. C. for one hour. Then, the cloth was taken out and dried on 
air at 35.degree. C. to 40.degree. C., followed by heat treatment at 
110.degree. C., to give a sensitizer carried on a carrier having cation 
groups. 
In a pool with dimensions of 25 m.times.12 m.times.15 m equipped with a 
circulator, there were provided two series of filter tanks equipped with 
change-over cocks. In each of the filter tanks, 15 sheets of the above 
cloth-like sensitizers (50 cm.times.50 cm) superposed on each other were 
assembled as filter material. 
Using one series of the filter tanks, circulation of water was conducted at 
the flow rate of 150 m.sup.3 /hour, followed by change-over to the other 
series by means of the change-over cock to continued the operation. In the 
meantime, used filter materials were exposed to the sunlight in the day 
time and thereafter filled again in the filter tank. The above procedure 
was repeated, thus using two series of the filter tanks alternately each 
for 24 hours, to continue the running for 14 days. In every 3 hours, 
sampling of water was performed for 8 times per day for testing E. coli 
microorganisms. During said running, there was added no chemical such as a 
sterilizer into the pool at all. 
Using 10 ml of water to be tested, the number of living E. coli 
microorganisms was measured by the agar culture method. Table 17 shows the 
results, indicating the number of the tests among 8 per day wherein there 
was detected at least one/10 ml of E. coli. 
COMATIVE EXAMPLE 15 
Using cloths prepared by the same method as in Example 24 except for using 
no compound No. 23 dibromo-dibenzopyrenequinone, evaluation was conducted 
under totally the same conditions as in Example 4 to obtain the results as 
shown in Table 17. 
TABLE 17 
______________________________________ 
1st day 
3rd day 5th day 10th day 
14th day 
______________________________________ 
Example 24 
0 0 0 0 0 
Comparative 
1 8 8 8 8 
example 15 
______________________________________ 
EXAMPLE 25 
According to the same procedure as described in Example 24 except for 
changing the compound No. 23 dibromo-dibenzopyrenequinone to the compound 
No. 11 dibenzopyrenequinone and the cotton cloth to 6-nylon cloth, there 
was prepared a cloth-like sensitizer. 
Five sheets of the above cloth-like sensitizer (50 cm.times.50 cm) were 
superposed on each other and provided for use as the filter for an 
air-conditioner for an aseptic laboratory with dimensions of 4 m.times.7 
m.times.3 m capable of maintaining thermostatical and humidistatical 
conditions under circulation of the air. Running was continued for 24 
hours under the flow rate of 40 m.sup.3 /hour. After 24 hours, a new set 
of five sheets of the filter was filled to replace the used filters. While 
continuing the running, the used filters were subjected to treatment under 
20,000 luxes by means of a metal halide lamp for 2 hours. This procedure 
was repeated by using alternately the two set of filters to perform 
continuous running for 14 days. One time in a day during said running, the 
number of miscellaneous microorganisms contained in the aseptic room was 
measured by collecting microorganisms using an air-sampler on a membrane, 
followed by cultivation. The results are shown in Table 18. 
COMATIVE EXAMPLE 16 
Example 25 was repeated except for effecting no irradiation of light to 
obtain the results as shown in Table 18. 
TABLE 18 
______________________________________ 
Miscellaneous microorganisms in the 
aseptic room (cells/100 liter) 
1st day 
4th day 7th day 10th day 
14th day 
______________________________________ 
Example 25 
0 0 0 0 0 
Comparative 
10 20 20 30 30 
example 16 
______________________________________ 
EXAMPLE 26 
In 15 liter of water containing 150 ppm of cyanides, there was dispersed 
160 g of the sensitizer as prepared in Example 2. The dispersion was left 
to stand in the outdoors under aeration for 7 hours. During this period, 
the luminosity of the sunlight on the water surface in the above reactor 
varied in the range from 86,000 luxes at the maximum to 9,000 luxes at the 
minimum. 
After the above oxidation treatment, the concentration of cyanides was 
determined according to the method of JIS K 0102 to be 7.5 ppm. 
EXAMPLE 27 
In 3.6 liters of the filthy water for test having the water quality test 
values as shown in Table 19 was suspended 150 g of the sensitizer for 
heterogeneous system photosensitive oxidation as prepared in Example 2. 
The suspension was placed in the same reactor as used in Example 2 and the 
treatment was effected under oxygen atmosphere for 2 hours. After the 
treatment, followed by filtration of the reaction mixture, the filtrate 
was subjected to the water quality test according to the method as defined 
by JIS K0102. The results are shown in Table 19. 
EXAMPLE 28 
Example 27 was repeated, but the sensitizer for heterogeneous system 
photosensitive oxidation as prepared in Example 4 was used to obtain the 
results as shown in Table 19. 
COMATIVE EXAMPLE 17 
In water containing one part of Methylene Blue (light resistance test 
value=3), there was added 150 g of a commercially available ion-exchange 
resin (Amberlite IRC-84; Rohm & Haas Co.) and the mixture was left to 
stand at room temperature for 24 hours. After filtration and washing with 
water, there was prepared a sensitizer for heterogeneous system 
photosensitive oxidation. 
By use of this sensitizer, the same procedure as in Example 27 was repeated 
to give the results as shown in Table 19. 
COMATIVE EXAMPLE 18 
Example 4 was repeated except for omitting 
N,N'-dibenzoyl-1,4-diaminoanthraquinone. The resultant powders were used 
to repeat the same procedure as described in Example 27. The results are 
also shown in Table 19. 
EXAMPLE 29 
In 200 g of water in which 0.5 g of the compound No. 25 pyranthrone, 1 g of 
caustic soda and 1 g of hydrosulfite were dissolved, there was added 150 g 
of a styrene-divinylbenzene microporous gel (Amberlite XAD-4, trade mark, 
produced by Rohm & Haas, having an apparent surface area A CO.sub.2 780 
m.sup.2 /g) and the mixture was left to stand at 40.degree. C. for one 
hour. Then, the product was filtered and washed under running water for 
one hour to prepare a sensitizer for heterogenous system photosensitive 
oxidation. 
Example 27 was repeated by using this sensitizer to obtain the results as 
shown in Table 19. 
TABLE 19 
__________________________________________________________________________ 
Comparative 
Comparative 
Before 
Example 
Example 
Example 
example 
example 
treatment 
27 28 29 17 18 
__________________________________________________________________________ 
Appearance 
slightly 
trans- 
trans- 
trans- 
colored 
pale 
turbid, 
parent, 
parent, 
parent, 
in blue 
yellow 
pale color- 
color- 
color- 
yellow 
less less less 
Odor slight 
odor- 
odor- 
odor- 
odor- slight 
odor less less less less odor 
of of 
chemical chemical 
pH 6.8 6.9 7.2 6.9 5.9 6.8 
COD 420 11 31 5 225 399 
(ppm) 
Mass of 
27 less less less 19 29 
floating than than than 
matter 10 10 10 
(ppm) 
n-hexane 
16 less less less 9 14 
extract than than than 
(ppm) 2.0 2.0 2.0 
Content of 
5 ND ND ND 2 5 
phenols 
(ppm) 
Content of 
3 ND ND ND ND 3 
cyanides 
(ppm) 
__________________________________________________________________________ 
(Note) 
ND: not detected 
EXAMPLE 30 
The cloth-like sensitizer (30 cm.times.50 cm) for heterogeneous system 
photosensitive oxidation as prepared in Example 3 was filled in the same 
photochemical reactor as used in Example 2. While circulating the air 
containing 5 ppm of methyl mercaptan, irradiation of the light was 
effected for 3 hours. The methyl mercaptan content in the air after the 
treatment was measured to be less than 0.1 ppm and there was no odor 
detected in the air.