Year: 1898

page_text: We, FRANCIS MUDIE SPENCE and DAVID DICK SPENCE, both of The Manchester
Alum Works, Manchester, in the County of Lancaster, Manufacturing Chemists,
do hereby declare the nature of this invention to be as follows: —
This invention consists in improvements in the treatment of sewage in which
term we include other similar liquids containing putrescible excrementitious
substances and soapy or fatty matters.
The sewage discharged from many towns is of such a character that after its
putrescible substances have been precipitated in tanks by aluminoferric alone, it
yields an effluent which if used for irrigation tends to clog or choke up the land
to which it is applied, being charged with soapy or fatty matters remaining in
it in consequence of the sulphuric acid of the precipitant being insufficient in
amount to neutralize all the soda of such soapy or fatty matter.
The object of our invention is:-
(a) The production of a tank effluent which shall be so clear, neutral and
practically speaking free from soapy or fatty matters that it may be applied
as a liquid fertiliser to irrigable land year after year without any fear of
clogging it up.
(b) The recovery of the fatty matter from the sewage.
(c) The production of a manure better than that ordinarily produced from
the putrescible matter of sewage.
According to this invention we treat sewage either with aluminoferric or
aluminic sulphate or ferric sulphate but preferably with aluminoferric and also
either with sulphuric acid or hydrochloric acid in such proportions that the
alkalinity of the liquid is completely neutralised and the fat or fatty acid of
the soapy or fatty matters is precipitated along with the putrescible matter.
The clear liquid or effluent is then separated from the precipitated portion or
sludge by any suitable means.
The precipitated portion or sludge is freed or practically freed by pressing
and drying or by any other suitable means from the water associated with it.
The dried sludge is then treated in a suitable vessel with ether or bisulphide
of carbon or petroleum spirit or with any other suitable solvent or solvents with
the object of dissolving out the fat or fatty acid contained in such dried sludge.
The resultant liquid consisting of the solvent or solvents used and the fat or
fatty acid dissolved therein is then separated by filtration or otherwise from the
insoluble solid portion. The fat or fatty acid dissolved in such liquid is then
separated from the solvent or solvents by distilling off the solvent or solvents or
by any other suitable means which will enable the solvent or solvents to be
recovered for further use.
The fat or fatty acid may then be utilised for any purpose for which it may
be suitable either in the form in which it is obtained after separation from the

page_text: solvent or solvents or after being subjected to any purification which may be
requisite.
The portion of the sludge which was insoluble in the solvent or solvents above
referred to contains phosphoric acid and nitrogenous matter and after drying
it in any suitable way we utilise it as a manure. Unlike the dried sludge pro-
duced by precipitation from a highly alkaline sewage without neutralisation
which contains a portion of fatty acid in combination with the lime originally
present in the sewage the dried sludge obtained by our process is free from
fatty matter.
The effluent freed as above described from fatty matter and containing all
the valuable nitrogenous constituents of the sewage which were not precipitated
in the sludge, is now in the very best condition for application to irrigable land
in large quantities year after year without any tendency to choke or clog it up.
Our process applies only to alkaline sewages containing more alkali than
can be neutralised by the sulphuric acid present in the aluminoferric or aluminic
sulphate or ferric sulphate required to precipitate their putrescible matter.
Dated this Twenty-third day of July 1898.
HOWARD
CHEETHAM,
Manchester, Agent to the Applicants.
Improvements in the Treatment of Sewage.
We, FRANCIS MUDIE SPENCE and DAVID DICK SPENCE, both of The Manchester
Alum Works, Manchester, in the County of Lancaster, Manufacturing Chemists,
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:-
-
This invention consists in improvements in the treatment of sewage in which
term we include other similar liquids containing putrescible excrementitious
substances and soapy or fatty matters.
The sewage discharged from many towns is of such a character that after its
putrescible substances have been precipitated in tanks by aluminoferric alone, it
yields an effluent which if used for irrigation tends to clog or choke up the land
to which it is applied, being charged with soapy or fatty matters remaining in
it in consequence of the sulphuric acid of the precipitant being insufficient in
amount to neutralize all the soda of such soapy or fatty matter.
The object of our invention is:-
(a) The production of a tank effluent which shall be so clear, neutral and
practically speaking free from soapy or fatty matters that it may be applied.
as a liquid fertiliser to irrigable land year after year without any fear of
clogging it up.
(6) The recovery of the fatty matter from the sewage.
(c) The production of a manure better than that ordinarily produced from
the putrescible matter of sewage.
According to this invention we treat sewage either with aluminoferric or
aluminic sulphate or ferric sulphate but preferably with aluminoferric and also
with hydrochloric acid in such proportions that the alkalinity of the liquid is
completely neutralised as indicated by methyl orange in the way well known to
chemists and the fat or fatty acid of the soapy or fatty matters is precipitated
along with the putrescible matter. We find that from 10 to 20 cwts. of alumino-

page_text: ferric or of aluminic sulphate or of ferric sulphate and about 26 to 39 ewts. of
hydrochloric acid of a specific gravity of 115 are suitable quantities for the
precipitation and neutralisation of a million gallons of ordinary town sewage
but the quantity of each material required necessarily varies with the degrees
of impurity and of alkalinity of the sewage as ascertained by tests from time
to time. The aluminoferric or aluminic sulphate or ferric sulphate may be
used either in the form of slabs or lumps placed in the conduit delivering the
sewage into the precipitating tanks, or in the form of a regulated stream of a
solution of the material made to run into the conduit. The acid may be
delivered in the form of a regulated stream near the point at which the alumino-
ferric or aluminic sulphate or ferric sulphate is supplied. After the addition
of the aluminoferric or aluminic sulphate or ferric sulphate and the hydrochloric
acid the clear liquid or effluent is then by any suitable means separated from
the precipitated portion or sludge.
.
The precipitated portion or sludge is freed by pressing and drying or by any
other suitable means from the greater part of the water associated with it. The
dried sludge is then treated in a suitable vessel with ether or bisulphide of carbon
or petroleum spirit or with any other suitable solvent or solvents with the object
of dissolving out the fat or fatty acid contained in such dried sludge.
The resultant liquid consisting of the solvent or solvents used and the fat or
fatty acid dissolved therein is then separated by filtration or otherwise from the
insoluble solid portion. The fat or fatty acid dissolved in such liquid is then
separated from the solvent or solvents by distilling off the solvent or solvents or
by any other suitable means which will enable the solvent or solvents to be
recovered for further use.
The fat or fatty acid may then be utilised for any purpose for which it may
be suitable either in the form in which it is obtained after separation from the
solvent or solvents or after being subjected to any purification which may be
requisite, such for instance as distillation in a current of superheated steam.
The portion of the sludge which was insoluble in the solvent or solvents
above referred to contains phosphoric acid and nitrogenous matter and after
drying it in any suitable way free from the solvent or solvents and taking care
to recover the latter for further use, we utilise such insoluble portion as a
manure. Unlike the dried sludge produced by precipitation from a highly
alkaline sewage without neutralisation, which contains a portion of fatty acid
in combination with the lime originally present in the sewage, the dried sludge
obtained by our hereinbefore described process is freed from fatty matter and is
thus not only enriched in phosphoric acid and nitrogenous matter but is freed
from a manurially injurious constituent.
The effluent, freed as above described from fatty matter and containing all
the valuable nitrogenous and other fertilising constituents of the sewage which
were not precipitated in the sludge, is now in the very best condition for applica-
tion to irrigable land in large quantities year after year without any tendency
to clog or choke it up the land at the same time through its well known action
in withdrawing fertilising constituents from solution, still further purifying the
effluent.
As the purified and defatted effluent produced by our process contains sufficient
nitrogenous constituents to bring its potential value at present prices for sul-
phate of ammonia to about nine pounds sterling per million gallons those local
authorities who do not find in the recovered fat and the defatted manure a
sufficient inducement to utilise their sewage are now by our invention supplied
with a much stronger motive to do so; and even those authorities who have no
irrigable land in their immediate neighbourhood will now be enabled to utilise
their sewage by passing it through pipes to districts at a considerable distance
the outlay for the pipes being recouped by the value of the produce obtained from
the irrigating effluent.
Our process applies only to alkaline sewages containing more alkali than

page_text: can be neutralised by the sulphuric acid present in the aluminoferric or aluminic
sulphate or ferric sulphate required to precipitate their putrescible matter.
Having now particularly described and, ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:-
1. The hereinbefore described process for the treatment of sewage whereby
concurrently with the purification from putrescible matter and fat or fatty acid,
the fat or fatty acid is obtained from it substantially as described.
2. The hereinbefore described process for the treatment of sewage whereby
concurrently with its purification from putrescible matter and fat or fatty acid,
a defatted manure is obtained from it substantially as described.
3. The hereinbefore described process for the treatment of sewage whereby
concurrently with its purification from putrescible matter and fat or fatty acid
there is obtained from it a clear, neutral effluent containing all the valuable
fertilising constituents of the sewage not precipitated in the sludge and therefore
specially suitable for application in large quantities to irrigable land year after
year without any fear of ever clogging or choking up the latter.
Dated this Twenty-fifth day of April 1899.
HOWARD
CHEETHAM,
Manchester, Agent to the Applicants.