Method of disinfecting water with iodine species

A water treatment system and apparatus for producing bacteria- and virus-free water from a bacteria and virus-containing water supply, said apparatus comprising PA1 (a) generator means for holding solid elemental iodine and to allow solubilization of said iodine under dynamic aqueous flow; PA1 (b) means for feeding a first portion of said water supply to said generator means to produce an aqueous concentrated iodine solution; PA1 (c) means for providing a second portion of said water supply; PA1 (d) means for providing said aqueous concentrated iodine solution to said second portion of said water supply to provide a blended water supply; PA1 (e) storage means for holding said blended water supply to provide said bacteria- and virus-free water; PA1 (f) means for measuring water flow of said first and said second portions; PA1 (g) means for measuring the pH of said second portion; PA1 (h) means for adjusting the pH of said second portion; PA1 (i) means for measuring the temperature of said concentrated aqueous solution; and PA1 (j) control means for receiving flow data, pH data and temperature data from said means for measuring flow of said first and said second portions, said means for measuring pH of said second portion; said means for measuring temperature of said concentrated aqueous solution and means for adjusting pH of said second portion. The system provides an efficacious way of killing virus under the guidelines and standards set by the USEPA.

FIELD OF THE INVENTION 
This invention relates to a method of disinfecting water with iodine 
species, particularly, hypoiodous acid and dissolved molecular iodine. 
BACKGROUND TO THE INVENTION 
Iodine has been used for water disinfection on a large scale in the past. 
Iodine is used commonly also for its antibiotic (sensu stricto) effects 
against bacteria, viruses and cysts, as these three pathogens constitute 
the most common health risks in maintaining biologically safe water 
supplies. Traditionally, crystalline iodine is dissolved in water under 
static conditions by the addition of small amounts of KI, which greatly 
enhances the dissolution of the iodine. 
Of particular interest in a drinking water context, are those bacteria 
responsible for widespread occurrences and recurrences of intestinal 
infections in humans, namely, the coliform family of bacteria, e.g., E 
coli. These bacteria commonly contaminate drinking water supplies when 
waste water containing faecal material spills into a water supply, or when 
excessive anaerobic decay of vegetation in the water supply occurs. In 
general, the actual inactivation mechanism of the pathogenicity of both 
bacteria, viruses and cysts by iodine is poorly understood. 
Poliovirus 1 (Polio 1) is particularly prevalent in third world countries, 
where immunization programs are almost non-existent, and local drinking 
water supplies and sewage waters run side-by-side. 
To-date, iodine is generally provided from an iodophor source or as an 
aqueous solution by the use of KI to aid the dissolution of iodine. Most 
treatments employ pHs lower or higher than about 9. 
Dissolved iodine hydrolyzes in aqueous solutions to form hypoiodous acid, 
HOI, in amounts proportional to the pH of the solution, wherein above pH 
8.5, iodine is present almost exclusively as HOI. Both dissolved I.sub.2 
and HOI possess pathogenic properties. At pHs 5-7, iodine, as I.sub.2, 
exhibits antibacterial action and at higher pHs, e.g. 7-10, HOI is an 
efficient virucide. Chang (1) reports that above pH 8, HOI decomposes 
slowly to form iodide and iodate ions, especially in the presence of 
dissolved iodides. Neither iodides nor iodates have been found to be 
germicidal. Further, I.sup.- reacts with I.sub.2 to form the highly 
coloured I.sub.3.sup.- ion, which is also ineffectual as a germicide. 
Various tinctures of iodine may be generated upon dissolving the solid in 
organic liquids such as ethanol, acetone, diethyl ether, toluene, 
p-xylene, benzene and carbon disulphide. Additionally, many organic 
preparations of iodine may be generated by reacting appropriate organics 
with iodine, e.g., iodoform, methylene iodide. Among the most popular 
commercial iodine-organic complexes are the PVP-iodines, iodoforms and 
povidone-iodine preparations, which are used as detergents and 
antiseptics. Most of these compounds exhibit germicidal action upon 
dilution in water, whereupon the iodine is hydrated and released into the 
water, usually as molecular iodine. Many biocidal, organic iodine 
compounds are commonly referred to as iodophors. 
Traditionally, iodine-bearing resins are made by attaching I.sub.2, tri-, 
penta- and hepta-iodide ions to quaternary ammonium, styrene-divinyl 
benzene, cross-linked anion-exchange resins. Upon elution with water, the 
polyiodides and iodine are released from the resin via anion-exchange 
mechanisms. These resins are thought to operate on a demand-type basis, 
where iodine will only be released in the presence of a germicidal load in 
the water passing through the resins, by the following mechanisms; (1) 
iodine release aided by an internal exchange mechanism involving I.sub.2 
transfer through a polyiodide intermediate, (2) hydrolysis of iodine on 
the resin to produce HOI, (3) simple release of I.sub.2 by the 
resin-polyiodide combination and/or organic resin matrix. 
Berg et al (2) showed that, dissolved, elemental iodine in the presence of 
KI to enhance solubility of iodine at a pH=6 and an iodine concentration 
of about 2 ppm at 15.degree. C. killed Polio I to the 99.99% level after a 
1 minute contact time. Although this kill-level does comply with the USEPA 
(United States Environmental Protection Agency) guidelines, the 
experimental conditions do not, because the required kill must be achieved 
at 4.degree. C. Additionally, the amount of virus used was about 
4.13.times.10.sup.4 PFU/ml, which is about 2 times more than the USEPA 
testing protocol specifies. This reference shows that Polio 1 can be 
effectively killed at lower pH than traditionally expected by earlier 
research, that the rates of kill are increased with increasing 
concentration of iodine, and that iodine concentration falls with time. 
Hsu et al (3) teach that using dissolved elemental iodine in the presence 
of KI, pH=7, T=37.degree. C. and an iodine concentration of about 20 ppm, 
Polio 1 can be killed to about the 99.996% level after 10-20 minutes 
contact time. However, the reference also shows that the presence of 
iodide ion actually inhibits the rate and amount of viral inactivation. 
Although the kill ratios meet the USEPA guidelines, they only do so at 
body temperature, and not at the colder temperature required by the USEPA. 
A viral concentration of about 4.5.times.10.sup.5 PFU/ml, which is about 
20 times too strong, relative to the USEPA specifications was used. 
Cramer et al.,(4) have demonstrated that dilute tincture of iodine, at 30 
ppm. in contact with Poliovirus Type 3 for 30 minutes, at a pH of 10 and 
T=27.degree. C. kills to about the 99.99999% level. However, although 
USEPA-required kill ratios were achieved, these were not under the 
strenuous conditions dictated by the USEPA testing protocol. Further, 
unfortunately, the experiments involved about 1.times.10.sup.6 PFU/ml of 
Polio 3 which is about 300 times too much. 
Taylor and Butler (5) teach that Polio I at 30 .mu.M dissolved, elemental 
"Iodine", (specification unknown) at 5.degree. C. pH=9 and a 10 minute 
contact time kill Polio I to about the 99.8% level. However, the 
concentrations of virus or "Iodine" is not given. Further, USEPA kill 
levels were not met. 
Alvarez et al. (6) show that, at pH=10, T=25.degree. C. with a contact time 
of about 15 minutes, Polio 1 could be killed to the 90-99% level using 
about 1-2 ppm of iodine from a tincture. This reference also shows that 
iodine inactivates Polio 1 by affecting the ability of the virus to be 
absorbed by host cells. Unfortunately, these conditions did not meet the 
desired kill ratios set forth by the USEPA guidelines. 
Accordingly, there still remains a need for an efficacious process for 
killing viruses, particularly Polio I, that satisfies the USEPA 
experimental guidelines and kill standards and which process also kills 
bacterial to the degree as presently seen in the art. 
PUBLICATIONS 
1. Chang, S. L., J. Amer. Pharm. Ass., (1958), 47, pp. 417-423. 
2. Berg G. et al. Virology (1964), 22, pp. 469-481. 
3. Hsu et al. Journal of Epidemiology (1996), 82, 3, pp.317. 
4. Cramer W. N. et al (1976), 48, 1, pp.61-76. 
5. Taylor G. R. and Butler M., J.Hyg.Camb., (1982), 89, pp. 321-328. 
6. Alvarez M. E. and O'Brien R. T. Applied & Environmental Microbiology 
(November 1982), 44, 5, pp. 1064-1071. 
SUMMARY OF THE INVENTION 
It is an object of the present invention to provide an efficacious process 
for killing bacteria present in drinking water, which process meets the 
USEPA guidelines. 
It is a further object to provide an efficacious process for killing 
viruses present in drinking water, which process meets the USEPA 
guidelines. 
It is a yet further object to provide a water treatment system and 
apparatus which provides the aforesaid two objects of the invention. 
Accordingly, in one aspect the invention provides a method of disinfecting 
water to kill bacteria and viruses using iodine species comprising 
hypoiodous acid and iodine in aqueous solution, said method comprising 
treating said water containing said bacteria and viruses with a 
disinfecting effective amount of said iodine species at a pH selected from 
9-10 to provide bacteria and virus-free water. 
Preferably, the iodine species concentration is selected from 2-200 ppm 
and, more preferably, 10-20 ppm. Most preferably, the disinfecting 
solution consists essentially of HOI and I.sub.2. 
By the term iodine species as used in this specification is meant, 
collectively, dissolved molecular iodine and hypoiodous acid species 
present over the pH range 9-10. The ppm concentrations herein refer to the 
concentrations of these species determined as iodine species which are 
chemically free to react with pathogens, i.e. the total amount of I.sub.2 
and HOI. 
We have found that a suitable contact time ranges from about 1 to 30 
minutes at pH 9-10, and depends on the temperature and iodine species 
concentration. In the dynamic process aspect of the present invention, a 
suitable contact time is about 10 minutes at a pH of 9.5, concentration of 
10-15 ppm and temperature of between 12.degree.-18.degree. C. 
In a preferred aspect of the invention, the efficacious iodine 
species-containing water is prepared by blending a minor amount of 
relatively highly concentrated iodine species solution with a major amount 
of untreated water under the treatment conditions as hereinbefore defined. 
Most preferably, we have found that a most satisfactory method of attaining 
a suitably iodine species-concentrated aqueous solution is under dynamic 
aqueous flow conditions wherein a flow of water is passed through 
elemental iodine in the form of flakes at such a rate as to produce a 
desired concentration, preferably 100-500 ppm. Addition of this 
concentrated solution to the main water supply to be treated is at a rate 
as to produce the desired 10-20 ppm iodine species concentration. 
In a further aspect, the invention provides a water treatment system for 
producing bacteria- and virus-free water from a bacteria- and 
virus-containing water supply, said system comprising 
(a) generator means for holding solid elemental iodine and to allow 
solubilization of said iodine under dynamic aqueous flow; 
(b) means for feeding a first portion of said water supply to said 
generator means to produce an aqueous concentrated iodine solution; 
(c) means for providing a second portion of said water supply; 
(d) means for providing said aqueous concentrated iodine solution to said 
second portion of said water supply to provide a blended water supply; 
(e) storage means for holding said blended water supply to provide said 
bacteria- and virus-free water; 
(f) means for measuring water flow of said first and said second portions; 
(g) means for measuring the pH of said second portion; 
(h) means for adjusting the pH of said second portion; 
(i) means for measuring the temperature of said concentrated aqueous 
solution; and 
(j) control means for receiving flow data, pH data and temperature data 
from said means for measuring flow of said first and said second portions, 
said means for measuring pH of said second portion; said means for 
measuring temperature of said concentrated aqueous solution and means for 
adjusting pH of said second portion. 
Most preferably, excess iodine species may be readily removed from the 
treated water by means of iodine and/or iodide strippers.

DESCRIPTION OF PREFERRED EMBODIMENT 
With reference to FIG. 1, the system comprises a water feed inlet conduit 
10 which feeds inlet water to a preconditioner 12. The incoming source 
water is, typically, a municipal drinking water, hereinafter referred to 
as the "main flow" which enters the system at, typically, ambient 
temperature. However, the system of the invention is designed to accept 
water also at other temperatures of between 0.degree.-40.degree. C. 
Preconditioner 12 is an optional feature and contingent upon the quality 
and chemistry of the source water and preconditioner may include 
prefilters, as well as water softeners or phenol scrubbers. 
Main flow water exits preconditioner 12 and passes throughout the system 
through conduit 14. A pressure gauge 16 measures the pressure of the 
incoming source water, which pressure is monitored by a computerized 
controller 18, such that the pressure never exceeds the operating 
conditions, typically, 45-100 psi. If the pressure limits are exceeded, 
the system shuts down. A flow meter 20 measures the flow of the main flow 
and provides this information to controller 18. The operation of the 
system of this embodiment is controlled to provide a flow rate value 
selected from between 0-12 USGPM. 
Conduit 14 leads to a carbon pre-filter 22 to remove unwanted halogen, 
trihalo methane and organic residuals and to a particle filter 24 of, 
typically, wound cotton providing greater than 5 micron filtration to 
remove fine mineral, organic and carbon particles. Downstream of filter 24 
is a pH control station shown generally as 23 having an acid and/or base 
reservoir 26 and a static mixer 28. Reservoir 26 provides acid or base as 
the case may be under the control of controller 18 upon pH information 
provided by a pH meter 30. The preferred base for addition is sodium 
hydroxide and is mixed with the main flow by means of the static, in line 
mixer 28. 
The pH adjusted-main flow exits static mixer 28 and a portion of the main 
flow is diverted through a iodine-generator and iodine-sensor loop shown 
generally as 31 comprising a side conduit 32, pump 34, flow meter 36, two 
iodine generators 38 in series and iodine sensor 40. The iodine sensor at 
the wavelength used detects total free iodine, i.e. both I.sub.2 +HOI. 
Iodine generators 38 comprise PVC canisters which contain crystalline 
iodine and have water-entry and liquor-exit holes (not shown). The 
resultant concentrated iodine solution, herein called "liquor" is blended 
back into the main flow at a carefully monitored and controlled rate by 
controller 18. The temperature of the liquor is measured by a thermometer 
42 and reported to controller 18 as is the pH of the blended main flow in 
conduit 14 as measured by a pH meter 44. 
Blended main flow is fed through a cyst filter 46 to residence contact tank 
48. Cyst filter 46 removes particles and cysts (e.g protozoans, emoebas) 
having a diameter greater than about 1 micron. From residence tank 48, 
conduit 14 passes the treated blended main flow water to an activated 
carbon iodine stripper 50, which effectively removes any free iodine 
species e.g. molecular iodine and hypiodous acid from the blended main 
flow. Treated water from iodine stripper 50 is passed to an iodide 
ion-exchange stripper 52, containing e.g. Purolite resin. Iodine-free, 
disinfected potable water is discharged from stripper 52 for subsequent 
use. 
The following description illustrates a typical process according to the 
invention using the apparatus described hereinabove. 
Municipal water is fed through inlet conduit 10 through preconditioner 12 
at a flow rate selected from 4.5-12 USGPM, pH 5-9, temperature 10.degree. 
C. and pressure of 85 psi. as measured by pressure gauge 16 under the 
influence of computer controller 18. Main flow water enters and leaves 
carbon filter 22 wherein the pH of the main flow is increased by 1-2 pH 
upon passing therethrough. The amount of acid or alkali, generally sodium 
hydroxide, delivered to the main flow as 10 molar sodium hydroxide is such 
that the iodinated blend water as measured by pH meter 44 has a pH of 
9.5.+-.0.2 pH. The amount of main flow diverted through loop 32 is 
controlled by controller 18 and where upon controller 18 instructs pump 34 
to deliver an appropriate flow to iodine generators 38 as to generate 
sufficient aqueous iodine species for the production of a final 
concentration of 10 ppm. free iodine in blended main flow line 14. A 
typical flow through loop 32 is 0.08-1.46 USGPM (166 ml./min.-2806 
ml./min.) to provide a resultant concentrated iodine value of 100-500 ppm. 
by passage of the side stream through generators 38 each containing 1.75 
kg. pure, crystalline iodine in flake form. Flow rate, temperature and 
pre-determined solubility curves enable the correct iodine concentration 
to be generated as determined by sensor 40. Iodine sensor 40 is, 
preferably, an in-line, spectrophotometric flow-through cell with a 
dedicated detector tuned to 460 nm for the detection of coloured iodine 
species, chiefly hypoiodous acid. The main function of sensor 40 is to 
inform controller 18 when the iodine concentration of the liquor drops 
below about 130 ppm. Digital thermoprobe monitor 42 measures the 
temperature of the liquor as it emerges from sensor 40. The temperature 
value is fed to controller 18 where it is applied to an equation governing 
the liquor/pump rate, such that the concentration of the liquor and, 
hence, the blended flow is suitable. It is most preferred that sensor 40 
is located within loop 32 as shown in view of the likelihood that the 
system may sit idle for hours or days, whereupon iodine crystals and the 
liquor in immediate contact therewith may equilibrate to ambient 
temperature--which may be different from that of the incoming source 
water. If temperature sensor 42 is placed in conduit 14 upstream of loop 
32, an incorrect amount of iodine liquor could be fed into main line 14 
upon blending. In the present embodiment, location of the temperature 
probe accounts for any gradual cooling or warming of the liquor within the 
iodine-generator loop, such that corresponding changes in liquor 
concentration as the temperature of the system re-equilibrates the 
temperature of the incoming source water. pH meter 44 reports to 
controller 18 to instruct pH control station 23 to add the appropriate 
amount of sodium hydroxide, such that the pH of the blended flow after 
iodination is 9.5. 
The iodinated, blended flow is controlled to provide a free iodine 
concentration selected between 10-20 ppm. The process of the invention, as 
hereinabove described, operates under a residence time for the iodinated 
water of 10 minutes to ensure mortality of any viruses and bacteria within 
the main flow, caused mainly by the presence of HOI at pH 9.5. Passage of 
the blended iodinated main flow through iodine stripper 50 raises the pH 
of the main flow by about 1-2 pH units. The activated carbon converts some 
of the available free molecular iodine to iodides. Passage of the 
resultant solution through iodide stripper 52 causes the pH of the 
discharge water to drop by 3-4 units. Trace amounts of molecular iodine 
(2-4 ppm) may also be removed by the ion exchange resin. The acceptable 
value for total iodine concentrations, at this stage, is 40 ppb or less. A 
resultant pH of 5-7 for the discharged water is most acceptable. 
Controller 18 is a sophisticated pre-programmed computer capable of 
monitoring and controlling the desired aspects of the process within the 
system by communicating with pH, temperature, pressure, flow and I.sub.2 
sensors placed at strategic locations, as hereinbefore described. 
In the embodiment described herein, the controller is accessible via a user 
operated keypad, such that system parameters may be changed to fine-tune 
the system when installation occurs, or in the event of a system error, to 
effect shutdown. Certain operator-defined system parameters may be altered 
from original input values to compensate for variation in physical and 
chemical conditions encountered in the field, e.g., pressure, flow rates. 
Other parameters may be changed by the user to reflect the specific needs 
of the duty, e.g., iodine concentration and pH of output water. By sensing 
the temperature and pH of the incoming source water, the controller is 
able to adjust the pH of the water to about 10.0, such that the 
dissolution of the iodine then becomes temperature dependent only, and the 
concentration of iodine in main line 14 is about 10 ppm. Controller 18 is 
pre-programmed with temperature vs solubility curves for iodine, such that 
the appropriate amount of liquor at the correct iodine concentration is 
delivered into the main flow. The dissolution of iodine effects a pH drop 
of about 0.5 pH units while the pH of water in the main line will be 
adjusted to about 9.5. 
EXAMPLES 
Example 1 
An evaluation of the virucidal activity on Poliovirus Type I of the process 
of the invention, which process provides a 10 ppm iodinated test water, pH 
9.5 at 4.degree. C. at a 10 minute exposure, was conducted under the 
following protocol. 
100 ml. each of (i) distilled water at pH=7.25, (ii) municipal Dartmouth 
(Nova Scotia, Canada) water adjusted to pH=9.5; and (iii) Test Water were 
dispensed in glass bottles and chilled to refrigeration temperature. Stock 
Poliovirus Type 1 (P1), the test virus, in a 10 .mu.l aliquot containing 
approximately 2.6.times.106 plaque-forming units (PFU) was added to each 
sample to yield a titer of 2.6.times.10.sup.4 PFU/ml in each test sample. 
Each sample was incubated 10 minutes in a refrigerator, with occasional 
mixing, subsequently 2 ml. of 0.1% sodium thiosulfate solution was added 
to each sample to stop further action of iodine and residual virus 
infectivity in each of the solutions was determined by plaque assay on 
6-well BGMK (Buffalo Green Monkey Kidney cells) monolayer cultures. 
Example 2 
A similar evaluation to that of Example 1 was conducted on test water (2) 
treated according to the invention at a pH of 10.10, at 10 ppm I.sub.2 at 
12.degree.-14.degree. C. for 10 minutes. 
100 ml. each of (i) distilled water at pH 7.25, (ii) Dartmouth water 
adjusted to pH=9.5 and (iii) test water (2) were dispensed in glass 
bottles and left to stand at about 12.degree.-.degree. C. Stock Poliovirus 
Type 1 (P1), the test virus, in a 10 .mu.l aliquot containing 
approximately 2.6.times.10.sup.6 plaque-forming units (PFU) was added to 
each sample to yield a titer of 2.6.times.10.sup.4 PFU/ml in all three 
test samples, respectively. After 1 minutes of incubation at 
12.degree.-14.degree. C. with occasional mixing, 2 ml. of 0.1% sodium 
thiosulfate solution was added to each sample to stop further action of 
iodine and residual virus infectivity in each of the solutions was 
determined by plaque assay on 6-well BGMK monolayer cultures. 
TABLE 1 
__________________________________________________________________________ 
Table 1 presents bactericidal and virucidal results from selected 
Literature. 
Contact 
time 
Iodine Iodine 
Reference 
Pathogen 
pH T .degree.C. 
(min.) 
source conct. (ppm) 
% Kill 
__________________________________________________________________________ 
Bacteria 
faecal 7-8.5 20.degree. 
30 ? 1-8 10 
coliform 
E. coli 6, 7.5 
5, 20, 35.degree. 
30 ? 1-10 100 
Virus 
2. Polio 1 6 15.degree. 
20 elemental I.sub.2 + KI 
.2-2 99.99 
3. S. abortivoequina 
7 37.degree. 
10-20 
elemental I.sub.2 + KI 
.1-20 
E. coli 
H. influenzae 
f2 bacteriophage 
Polio 1 99.996 
4. Polio III 
4, 6, 7, 10 
27.degree. 
30 tincture of iodine 
30 99.99999 
5. Polio 1 5, 7, 9 
5.degree. 
10 elemental I.sub.2 
8 99.9 
f2 bacteriophage 
6. Polio 1 5, 8, 6, 7, 10 
25.degree. 
15 tincture of iodine 
.8-2.5 
90-99.9 
__________________________________________________________________________ 
Table 2 presents the efficacy of iodination according to the process of the 
present invention under the stated conditions against K.pneumonia 
bacterium. The results show that iodinated water at the relatively high pH 
of 9.5 is as satisfactory as the expected iodination at lower pH 6. The 
results show that the USEPA guidelines are met, in terms of requisite kill 
levels at 4.degree. C. against the virulent K.pneumonia bacterium. 
TABLE 2 
__________________________________________________________________________ 
Bacteria 
Infusion 
Recovered 
% Kill (rel. to 
Sample 
(I.sub.2) 
pH T t Species 
(pfu/ml) 
(pfu/ml) 
control) 
__________________________________________________________________________ 
Iodinated 
2 ppm 
5.90 
4.degree. C. 
10 min. 
K pneumonia 
2.74 .times. 10.sup.6 
&lt;10 99.9996 
water 
Iodinated 
4 ppm 
5.99 
4.degree. C. 
10 min. 
K. pneumonia 
2.74 .times. 10.sup.6 
&lt;10 99.9996 
water 
Iodinated 
8 ppm. 
6.07 
4.degree. C. 
10 min. 
K. pneumonia 
2.74 .times. 10.sup.6 
&lt;10 99.9996 
water 
Distilled 
0 ppm 
9.48 
4.degree. C. 
10 min. 
K. pneumonia 
3.60 .times. 10.sup.7 
too numerous 
confluent 
water to count 
overgrowth 
Iodinated 
10 ppm 
9.49 
4.degree. C. 
5 min. 
K. pneumonia 
2.60 .times. 10.sup.7 
2.1 .times. 10.sup.1 
99.999942 
water 10 min. 0 
Iodinated 
water 
10 ppm 
9.49 
4.degree. C. 
5 min. 
K. pneumonia 
3.60 .times. 10.sup.7 
9.5 .times. 10.sup.1 
99.981 
10 min. 0 
__________________________________________________________________________ 
TABLE 3 
__________________________________________________________________________ 
Table 3 presents the efficacy of iodination according to the process of 
the present 
invention under the stated conditions against Poliovirus I. The results 
show the efficacy 
of the iodination process according to the invention against Polio 1. The 
process of the 
invention closely follows the USEPA test protocols and exceeds requisite 
kill ratios. 
Viruses 
Infusion 
Recovered 
% Kill (rel. to 
Sample 
(I.sub.2) 
pH T t Species 
(pfu/ml) 
(pfu/ml) 
control) 
__________________________________________________________________________ 
Test Water 1 
10 ppm 
9.5 
4.degree. C. 
10 min. 
Poliovirus 1 
2.6 .times. 10.sup.4 
2 99.992 
Dartmouth 
0 ppm 
9.5 
4.degree. C. 
10 min. 
Poliovirus 1 
2.6 .times. 10.sup.4 
2.53 .times. 10.sup.4 
2.700 
water 
Distilled 
0 ppm 
7.25 
4.degree. C. 
10 min. 
Poliovirus 1 
2.6 .times. 10.sup.4 
2.42 .times. 10.sup.4 
6.930 
water 
Test Water 2 
10 ppm 
10.00 
12.degree. C. 
10 min. 
Poliovirus 1 
2.6 .times. 10.sup.4 
0 100.000 
Dartmouth 
0 ppm 
9.5 
12.degree. C. 
10 min. 
Poliovirus 1 
2.6 .times. 10.sup.4 
2.53 .times. 10.sup.4 
2.700 
water 
__________________________________________________________________________ 
Although this disclosure has described and illustrated certain preferred 
embodiments of the invention, it is to be understood that the invention is 
not restricted to those particular embodiments. Rather, the invention 
includes all embodiments which are functional or mechanical equivalence of 
the specific embodiments and features that have been described and 
illustrated.