AN IMPROVED METHOD OF PURIFYING SEWAGE
Year: 1881

page_text: LETTERS PATENT to Peter Spence, of Manchester, in the County of Lancaster,
Manufacturing Chemist, for an Invention of "AN IMPROVED METHOD OF
PURIFYING SEWAGE."
.
PROVISIONAL SPECIFICATION left by the said Peter Spence at the Ollico
of the Commissioners of Patents on the 29th September 1881.
PETER SPENCE, of Manchester, in the County of Lancaster, Manufacturing
Chemist. "AN IMPROVED METHOD OF PURIFYING SEWAGE."
My Invention relates to improvements upon that process of purifying sewage
for which Letters Patent were granted to me, dated 1st June 1880, No. 2227.
My present improvements consist chiefly in dispensing with the preliminary
treatment of sewage by lime, as described in the Specification of the Letters
Patent above referred to.
I now propose to take the sewage and run it over or through one or more tanks,
to allow heavy, solid, and gritty matter to settle and become separated therefrom,
such matter to be removed in any convenient manner from the said tanks as they
in time become filled.
The sewage, after being freed from heavy, solid, gritty matter, I run into the
usual series of tanks, and add thereto salts of alumina or alumina and iron in
sufficient quantity to cause all the dissolved and suspended feculent and other
matter contained in the sewage to be precipitated and fall to the bottom of the
before named tanks as light flaky matter or magma.
The aforesaid salts of alumina or alumina and iron I prefer to use in a liquid
form, and they may either flow into the stream of sewage on its passage to the
before named series of tanks, or may be added to the said tanks as they become
filled with sewage.
I now by pumping or in any other convenient manner remove the aforesaid
flaky matter or magma from the bottom of the aforesaid tanks into suitable vessels,
and add thereto sulphuric or other acid.

page_text: The acid will cause all the alumina and iron to be dissolved, and the resulting
solution of the recovered alumina and iron I add to a further quantity of sewage,
as above described, regulated additional quantities of salts of alumina or alumina
and iron above referred to being added to it to make up for any waste of such
salts that may have taken place.
The black flaky matter left after the action of the sulphuric or other acid
on the magma pumped from the tanks I subject to a pressing or squeezing process
in well known apparatus, the liquid resulting therefrom being used as recovered
solution; the remaining solid matter is then valuable for manure.
The liquid or purified sewage from the last of the series of tanks having deposited
all the precipitated magma, and being now clear and transparent, may be made to
flow away in any convenient manner, and without risk of contaminating the streams
into which it may be directed.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Peter Spence in the Great Soal Patent Office on the 29th March
1882.
PETER SPENCE, of Manchester, in the County of Lancaster, Manufacturing
Chemist. "AN IMPROVED METHOD OF PURIFYING SEWAGE"
My Invention relates to improvements upon that process of purifying sewage
for which Letters Patent were granted to me, dated First day of June, One
thousand eight hundred and eighty, No. 2227. My present improvements consist
chiefly in dispensing with the preliminary treatment of sewage by lime, as
described in the Specification of the Letters Patent above referred to. I now
propose to take the sewage and run it over or through one or more tanks, to allow
heavy, solid, and gritty matter to settle and become separated therefrom, such
matter to be removed in any convenient manner from the said tanks as they in
time become filled. The sowage, after being freed from heavy, solid, gritty matter,
I run into the usual series of tanks, and add thereto salts of alumina or of alumina
and iron in sufficient quantity to cause all the dissolved and suspended feculent
and other matter contained in the sewage to be precipitated and fall to the bottom
of the before named tanks as light flaky matter or magina. The aforesaid salts of
alumina or alumina and iron I prefer to use in a liquid form, and they may either
flow into the stream of sewage on its passage to the before named series of tanks,
or may be added to the said tanks as they become filled with sewage. I now by
pumping or in any other conveniont manner remove the aforesaid flaky matter or
magma from the bottom of the aforesaid tanks into suitable vessels, and add
thereto sulphuric or other acid. The acid will cause the alumina and iron to be
dissolved, and the resulting solution of the recovered alumina and iron I add to a
further quantity of sewage, as above described, regulated additional quantities of
salts of alumina or alumina and iron above referred to being added to it to make
up for any waste of such salts that may have taken place. The black flaky matter
left after the action of the sulphuric or other acid on the magma pumped from the
tanks I subject to a pressing or squeezing process in well known apparatus, the
liquid resulting therefrom being used as recovered solution; the remaining solid
matter is then valuable for manure. The liquid or purified sewage from the last
of the series of tanks having deposited all the precipitated magma, and being now
clear and transparent, may be made to flow away in any convenient manner, and
without risk of contaminating the streams into which it may be directed. In
order that my Invention may be more thoroughly understood I will now proceed
to more particularly describe the same. I take the sewage as it comes from tho
sewers, and allow it to flow into a small tank or reservoir for the purpose of
allowing any gritty or heavy matter contained in the sewage to be separated
therefrom. I then allow the sewage to flow into settling tanks, and as it flows
therein I run along therewith a solution of salts of alumina or alumina and iron
for this purpose. I prefer to make use of the article known as alumino-ferric cake,
and I add this in the proportion which may be found necessary for the class of
sewage on which I am operating, using the minimum quantity that will render the
effluent water of the sewage fit for being run into any stream or river. The
quantity of alumino-ferric cake required for the above purpose I find to vary
from one ton of the cake aforesaid to from one to five million gallons of sewage, or
even in some cases a greater difference. In the settling tanks before referred to
the impurities of the sewage will be found to have settled to the bottom as a
flocculent or flaky magma, which I continuously remove by pumping, or in any

page_text: other suitable manner, and transfer it to other tanks, and add thereto a quantity of
dilute sulphuric acid sufficient to dissolve all the alumina and iron that have been
precipitated. This solution is rapidly effected, and after settlement of the insoluble
flaky matter the liquid may be used along with fresh quantities of sewage for the
same purpose and to the same extent as the original alumino-ferric cake, but
in practice it will be found requisite to supplement the solution by means of
additional alumino-ferric cake, as there may be a loss of iron and alumina. The
insoluble flaky magma may now be squeezed in a filter press or other suitable
apparatus; the solution expressed may be again used as before, and the insoluble
matter after drying will become a valuable. manure. The effluent water from the
settling tanks, which after the removal of the magma will be transparent and
nearly colourless, may be made to flow into any desired stream.
Having thus described and ascertained the nature of my said Invention, and the
manner in which the same is to be performed, I desire it to be understood that I
claim as secured to me under the above in part recited Letters Patent,―
Firstly. The purification of sewage, after allowing gritty matter to settle there-
from, by the direct application thereto of salts of alumina or of alumina and iron in
sufficient quantity to make a clear and nearly colourless effluent, and the recovery
of the alumina and oxide of iron, as described, for subsequent use in the same or in
a similar process.
Secondly. The use of the residual magma after separating the recovered alumina
and iron in solution as a manure.
In witness whereof, I, the said Peter Spence, have hereunto set my hand
and seal, the Twenty eighth day of March, in the year of our Lord One
thousand eight hundred and eighty two.