Year: 1886

page_text: Date of Application, 11th Dec., 1886
Complete Left, 6th Sept., 1887.
Complete Accepted, 14th Oct., 1887
I THOMAS BRIGHT WILSON of Hope View, Derby Road, Fallowfield, Manchester in
the County of Lancaster, Civil Engineer do hereby declare the nature of this Invention
to be as follows:-
My said invention relates to the treatment and purification of sewage and impure
liquids by precipitation and consists in novel combination of chemical re-agents to
form the solution admitted to the precipitating tanks, so as to remove or render
innocuous the offensive matter contained in the precipitate, and also to give increased
value to the deposit when such is intended to be used as a fertilizer. To the sewage
entering or contained in the settling tanks I add a solution of Sulphate of alumina
obtained by the action of Sulphuric acid on clays or aluminous shale or I may use a
solution of the sulphate of alumina produced in the manufacture of alum, or I may
use the manufactured alum. To this admixture of sewage and aluminous sulphate
I add a solution of Chloride calcium, a waste product of many manufactures, but
which may be directly produced by the action of hydrochloric acid on limestone. The
organic matter in the sewage is precipitated by the sulphate of lime and alumina
contained in the solutions and falls to the bottom of the tanks. The chlorine liberated
from the calcium combines with the free ammonia in the sewage to form chloride of
ammonia. Any excess of chloride of calcium has an antiseptic effect on the organic
matter present in the sewage. When the precipitation has been properly effected the
supernatant purified liquid is drawn off by a float pipe or other suitable means and the

page_text: precipitated deposit is removed, dried and pressed in the usual manner. When it is
intended to dispose of the precipitate as a fertilizer, I use a chloride of magnesium in
place of the chloride of calcium or for convenience and to effect a more speedy pre-
cipitation I may use a mixture of the two salts. The magnesia of the chloride by reason
of its great affinity for the phosphoric acid and ammonia contained in the sewage
combines to form a double salt with these agents and is precipitated with the sulphate
of lime and the alumina. To still further purify the water drawn off from the settling
tanks I prefer to pass it through a filter bed composed of the ferruginous compound
known as magnetic carbide of iron.
Dated this 10th day of December 1886
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.

page_text: COMPLETE SPECIFICATION.
Improvements in the Treatment and Purification of Sewage and
other Impure Liquids and in the Obtaining of Fertilizers
therefrom.
י
I THOMAS BRIGHT WILSON of Hope View Derby Road Fallowfield Manchester in
the County of Lancaster Civil Engineer do hereby declare the nature of this Invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My said Invention relates to the treatment and purification of sewage and impure
liquids by precipitation and consists in a novel combination of chemical re-agents to
form the solution admitted to the precipitating tanks so as to remove or render
innocuous the offensive matter contained in the precipitate and also to give increased
value to the deposit when such is intended to be used as a fertilizer. To the sewage
entering or contained in the settling tanks I add a solution of Sulphate of alumina
obtained by the action of sulphuric acid on clays or aluminous shale or I may use a
solution of the sulphate of alumina produced in the manufacture of alum or I may use
the manufactured alum. To this admixture of sewage and aluminous sulphate I add a
solution of Chloride calcium, a waste product of many manufactures but which may
be directly produced by the action of hydrochloric acid on limestone. The organic
matter in the sewage is precipitated by the sulphate of lime and alumina contained in
the solutions and falls to the bottom of the tanks. The chlorine liberated from the
calcium combines with the free ammonia in the sewage to form chloride of ammonium.
Any excess of chloride of calcium has an antiseptic effect on the organic matter present
in the sewage. When the precipitation has been properly effected the supernatant
purified liquid is drawn off by a float pipe or other suitable means and the precipitated
deposit is removed, dried and pressed in the usual manner. The proportions in which
the aforesaid precipitating agents are added to the sewage will depend upon the
amount of impurity contained in the sewage and on the required degree of purification.
In a typical case of very impure sewage containing say four parts per million of free
ammonia and say thirteen hundred grains of combustible organic matter per gallon a
good precipitation would be gained by adding equal parts of Sulphate of aluminia
and chloride of calcium say in the proportion of sixteen grains of each to each_gallon
of sewage. When it is intended to dispose of the precipitate as a fertilizer I use a
chloride of Magnesium in place of the chloride of calcium and in about the same
proportions or for convenience and to effect a more speedy precipitation I may use a
mixture of the two salts. The magnesia of the chloride by reason of its great affinity
for the phosphoric acid and ammonia contained in the sewage combines to form a
double salt with these agents and is precipitated with the sulphate of lime and the
alumina. To still further purify the water drawn off from the settling tanks I prefer
to pass it through a filter bed composed of the ferruginous compound known as
magnetic carbide of iron.

page_text: Having now particularly described and ascertained the nature of my said invention
I declare that what I claim is:-
In the purification of sewage by precipitation adding a solution of chloride of
calcium to a mixture of sewage and aluminous sulphate so as to precipitate the organic
matter in the sewage substantially as hereinbefore described.
Dated this 2nd of September 1887.
DUTTON & FULTON,
1, St. James Square, Manchester,
Agents.