Improvements in the Preparation of Precipitants for Use in the Treatment of Sewage and other Liquids Containing Solid Matters in Suspension and Solution, and Improvements in
Year: 1885

page_text: Improvements in the Preparation of Precipitants for Use in the
Treatment of Sewage and other Liquids Containing Solid
Matters in Suspension and Solution, and Improvements in
I WILLIAM BENJAMIN GEORGE BENNETT of Portswood in the County of Hants
Civil Engineer do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE PREPARATION OF PRECIPITANTS FOR USE IN THE TREATMENT OF
SEWAGE AND OTHER LIQUIDS CONTAINING SOLID MATTERS IN SUSPENSION AND
SOLUTION AND IMPROVEMENTS IN THE TREATMENT OF SUCH LIQUIDS " to be as
follows:-
:-
According to my Invention I take carbonized clay or carbonized earthy deposit
(such as peit) or carbonized shale rich in alumina and iron in a form soluble in
acid and reduce the said matter to an impalpable powder and treat the powdered
matter with cold dilute sulphuric acid or other suitable acid in sufficient quantity
to dissolve the soluble alumina aud iron thus producing sulphate of alumina and
iron or other salt of alumina and iron (according to the acid used) available in
water. The matter thus prepared (which I term acidified carbon) I use for
precipitating the matter in suspension and in solution in sewage and for the preci-
pitation of solids from other solutions.
In treating sewage with the said acidified carbon I prefer to make the sewage
alkaline by the addition of lime or other alkali and I place a quantity of the
acidified carbon in a suitable mixing machine and run it therefrom into the sewage
in the proportion of about ten grains of the acidified carbon to each gallon of
sewage. By this means rapid precipitation of the solid matters in suspension and
the oxidation of a great part of the organic matter in solution is produce with
deodorization and decolourization of the effluent which is consequently bright and
free from odour and not liable to putrefactive changes. The carbonaceous matter
being of much greater specific gravity than water the particles thereof assist con-
siderably in carrying down the organic matters in suspension together with the
flocculent precipitate produced and owing to the antiseptic property of the carbon
neither the sludge nor the effluent is liable to putrefactive changes.

page_text: My invention is applicable to the treatment of mill owner's refuse such as
the refuse liquid from paper mills woollen factories and the like and refuse
liquids liquids produced in other industries where a foul effluent or waste liquid is
required to be purified. Also in the refining and decolourizing of oils and other
liquids.
Although I have hereinbefore stated approximately the proportion in which
the acidified carbon may be advantageously used I do not limit myself to the said
proportion.
W. T. WHITEMAN,
Agent for the Applicant.
Improvements in the Preparation of Precipitants for Use in the
Treatment of Sewage and other Liquids Containing Solid
Matters in Suspension and Solution, and Improvements in
the Treatment of such Liquids.
I WILLIAM BENJAMIN GEORGE BENNETT of Portswood in the County of Hants
Civil Engineer do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN THE PREPARATION OF PRECIPITANTS FOR USE IN THE TREATMENT OF
SEWAGE AND OTHER LIQUIDS CONTAINING SOLID MATTERS IN SUSPENSION AND
SOLUTION AND IMPROVEMENTS IN THE TREATMENT OF SUCH LIQUIDS," and in what
manner the same is to be performed to be particularly described and ascertained
in and by the following statement:-
According to my invention I take either carbonized clay or carbonized earthy
deposit containing iron and alumina in a form which is soluble in acid and I dis-
integrate the matter selected preferably reducing it to an impalpable powder and
add to it after disintegration sulphuric acid of ordinary strength (commercially
known as oil of vitriol) in sufficient quantity to dissolve the soluble alumina and
iron contained in the matter to be treated and I then add water (preferably heated
to a temperature of from about one hundred and fifty degrees to two hundred and
twelve degrees Fahrenheit) in sufficient quantity to increase the volume of liquid
to the extent necessary to saturate the whole of the matter under treatment and
after the acid has dissolved the whole or nearly the whole of the soluble alumina
and iron present in the said matter I further add water (either cold or of any
temperature) in sufficient quantity to bring the mixture to such a consistence that
it will flow readily. Or before adding the acid to the carbonized matter I dilute
the acid with a quantity of water sufficient to produce the required consistence and
allow the mixture of dilute acid and carbonized matter to rest until the acid has.

page_text: acted as required on the aforesaid soluble constituents of the carbonized matter.
In the latter case the water added to the acid may be either cold or as warm as it
can be safely used having regard to the known effect of hot water upon oil of
vitriol. When the soluble alumina and iron have been dissolved by the acid the
mixture is ready for use the alumina and iron being then in a form in which they
will readily act on the liquids to be treated when such liquids are alkaline and
I use the said mixture for precipitating the matters in suspension and solution in
sewage and for the precipitation of solids from other matters and solutions as
hereinafter described.
I term the mixture prepared as hereinbefore described "Acidified carbon."
By the terms "carbonized clay" and "carbonized earthy deposit" I refer to the
product obtained by exposing to a carbonizing heat without free access of atmo-
spheric air either any artificial mixture of carbonaceous matter and earthy matter
containing iron and alumina in a form soluble in sulphuric acid (except those
mixtures of carbonaceous matter and earthy matter which are produced in the
form of sludge by the treatment of sewage) or any naturally occurring mixture of
ligneous or woody matter or non-mineral carbonaceous matter and clay or marl or
other earthy matter containing iron and alumina in a form soluble in sulphuric
acid Some kinds of peat and other ligneous deposits are examples of such naturally
occurring mixtures. The products obtained by the process described in the speci-
fications of the following Letters Patent are examples of carbonized clay and
carbonized carthy deposit which are suitable for treatment according to my
invention viz the Letters Patent No 3541 of 1877 granted to E. Johnson and
J. Robey and the Letters Patent No 9102 of 1884 granted to J. W. Gatehouse and
the Letters Patent No 14770 of 1884 granted to G. H. Ellis.
The proportion of acid required for the treatment of any given quantity of the
matters hereinbefore referred to is. dependent partly on the proportion of alumina
and iron and other basic substances (such as lime) contained in them therefore no
definite proportion which will be generally applicable can be stated. In treating
samples of "Dead's " carbon (by which name the product obtained as described in
the specification of the aforesaid Letters Patent N° 14770 of 1884 is known which
product contains only a fractional proportion of lime) about forty pounds weight
of sulphuric acid is sufficient per ton of the said product whereas in treating some
samples of carbonized clay and carbonized earthy deposit containing much lime
eighty pounds weight and upwards of sulphuric acid is required per ton.
must be taken to avoid using an excess of acid or a greater quantity than will com-
bine with the basic constituents of the matter to be treated as the mixture after the
action of the acid has ceased is required to be neutral.
Care
The time necessary for the sufficient action of the acid on the matter under
treatment may be ascertained by observing when the compound has become
neutral. In treating some matters of the kind herein before described this result
is obtained within a period of two hours.
In treating sewage with the liquid acidified carbon prepared as herein before
described I place a quantity thereof in a suitable mixing machine such as a pug
mill or in a machine of the kind ordinarily used in preparing milk of lime for
sewage treatment and termed a "mixer" and subject the acidified carbon to
agitation and run it from the said machine into the sewage in proportions varying
from five grains upwards of acidified carbon to each gallon of sewage the pro-
portion of acidified carbon necessary in any particular case being determined by the
strength of the sewage and the amount of solid matters contained in it and by the
nature of the sewage i,e whether contaminated with liquids from fictories or
consisting almost entirely of excrementitious matter and water commonly called
domestic sewage. In the latter case a low proportion of acidified carbon may be
used and in the case of refuse liquids from factories and of sewage contaminated
with such liquids a higher proportion of the acidified carbon is ordinarily required.
If the sewage to be treated be not alkaline I make it slightly alkaline before
adding the acidified carbon.

page_text: By the use of the said acidified carbon as herein before described rapid precipi-
tation of the solid matters-in suspension and the oxidation of a great part of the
organic matter in solution is produced with deodorization and decolourization of
the effluent which is consequently bright and nearly free from odour. The
carbonaceous matter being of much greater specific gravity than water the
particles thereof assist considerably in carrying down the organic matters in
suspension together with the flocculent precipitate produced and owing to the
antiseptic property of the iron salts and the carbon neither the sludge nor the
effluent is liable to putrefactive changes.
The cheapness of my acidified carbon also renders it very valuable for the said
purposes from a commercial point of view.
My invention is applicable to the treatment of refuse liquids from dye works
and other foul liquids capable of being clarified by chemical precipitation. In
treating the said matters I proceed as herein before described with reference to
sewage.
Although I have herein before stated approximately the proportions in which
the acidified carbon may be advantageously used I do not limit myself to the said
proportions.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
The treatment of the matters herein before referred to by the terms "carbonized
clay" and "carbonized earthy deposit" with sulphuric acid substantially as and
for the purpose herein before described.