Improved Method for Precipitating Solid Matter in Sewage, Purifying and Disinfecting the Effluent Water, and Solidifying and Preparing the Sludge for use as Manure.
Year: 1890

page_text: Date of Application, 29th Sept., 1890
Complete Specification Left, 29th July, 1891-Accepted, 28th Nov., 1891
PROVISIONAL SPECIFICATION.
Improved Method for Precipitating Solid Matter in Sewage, Purifying
and Disinfecting the Effluent Water, and Solidifying and Preparing
the Sludge for use as Manure.
We JOHN HARDWICK of No. 68 Northwold Road Upper Clapton Middlesex
Surveyor and LOUIS ARTHUR NEWTON of No. 83 Willis Road, Kentish Town,
Middlesex, Surveyor, do hereby declare the nature of this invention to be as
follows:-
Our invention relates to the treating of sewage and sewerage sludge by chemical
and mechanical process and the object of our invention is to precipitate all solid
matter in solution in sewage and to purify and disinfect the effluent water and
solidify the sludge. After pulverising a valuable manure is formed. The
ingredients we use for precipitating and disinfecting are as follows:-Sulphate of
lime, chloride of sodium, nitrate of lead, borax, alum, nitre, salicilic acid, oxy
muriatic acid, boricic acid and potash. For mixing and solidifying the said sewage
sludge we use Sulphate of lime, carbonate of lime, chloride of sodium, sulphur
and borax. The solidified sludge is then pulverised by machinery thus making a
valuable manure.
JOHN HARDWICK.
LOUIS ARTHUR NEWTON.
COMPLETE SPECIFICATION.
Improved Method for Precipitating Solid Matter in Sewage, Purifying
and Disinfecting the Effluent Water, and Solidifying and Preparing
the Sludge for use as Manure.
We, JOHN HARDWICK, of No. 68 Northwold Road, Upper Clapton, in the
County of Middlesex, Surveyor, and LOUIS ARTHUR NEWTON, of 83 Willis
Road, Kentish Town, in the County of Middlesex, aforesaid, Surveyor, 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 has reference to the treatment and utilization of sewage and it
has for objects to completely precipitate solid matters present in crude sewage, to
obtain a practically pure and disinfected effluent, and to convert the sewage sludge
into a form in which it can be conveniently and advantageously used as manure.
To precipitate the solid portions of the crude sewage and also matters in solution
therein, there is added to it an intimate mixture of sulphate of lime, chloride of
sodium, nitrate of lead, borax, common alum, and nitrate of potash to which may
be added, when the sewage has been considerably diluted by storm waters, a small
quantity of salicylic acid, hydrochloric acid and caustic potash.
Suitable quantities of the respective substances to employ for treating say one
million gallons of ordinary crude sewage are for example the following:-
Sulphate of lime say in the form of powdered
Gypsum
-
15 cwts.
Chloride of sodium
-
8 cwts.
-
30 pounds.
Nitrate of lead
Borax
-
Common alum
-
Nitrate of potash -
30 pounds.
1 cwts.
20 pounds.

page_text: be varied according to the particular nature of the sewage to be treated. In cases
where waste liquors containing one or more of the substances mentioned are
discharged into the sewage from chemical or other industrial works, the proportion
of such substance or substances in the above mentioned mixture can be reduced,
or even omitted if the proportion in the waste liquors, determined by analysis of
such liquor, be found sufficient. The substances mentioned are intimately mixed
together and gradually added in the form of a dry powder to the crude sewage
with which it should be intimately mixed. This may be done in any suitable
form of mixing apparatus. Such apparatus may comprise a vessel or channel into
which the mixture above referred to, is gradually added by a conveyor consisting
for example of buckets carried by an endless chain and intimately mixed by a
stirring device such as a paddle with the crude sewage which flows through the
vessel on its way to a settling tank. When a given quantity of sewage has been
thus treated, it is allowed to rest in the tank say for about three or four hours,
to allow solid matter to deposit when the supernatant liquid is run off, forming
a practically pure and disinfected effluent that can be safely run into a water
course. Usually we displace the supernatant liquid by allowing a further quantity
of treated sewage to flow into the settling tank above the deposit therein and
below the surface of the supernatant liquid this additional quantity of sewage
being allowed to rest as before. These operations are repeated until a suitable
quantity of sewage sludge is obtained from which the supernatant liquid last
remaining can be syphoned off. When using salicylic acid, hydrochloric acid and
nitrate of potash with the other substances mentioned for treating. sewage diluted
by storm waters as previously mentioned, suitable quantities are the following :-
J..
Salicylic acid
Hydrochloric acid
Caustic potash
3 pounds
3 pounds
20 pounds.
'
The sewage sludge thus obtained is then filtered which may advantageously be
effected in filter presses of the kind known as Johnson's filter presses into which
the sludge may be pumped direct from the settling tank. The solid sewage matter
from the filter press is then intimately mixed with sulphate of lime, say, in the
form of powdered gypsum, carbonate of lime in the form say of chalk, chloride of
sodium, powdered sulphur, borax and powdered magnesite for the purpose of fixing
the ammonia and other volatile substances present in the sewage and for converting
the sewage into a form in which: it can be conveniently and advantageously used 3
as a manure. Suitable quantities of these substances to mix with say three tons of
sewage matter from the filter press, are the following
Sulphate of lime
Carbonate of lime
:―
15 cwt.
4 cwt.
Chloride of sodium
2 cwt.
20 pounds
Sulphur
Borax
Magnesite
-
20 pounds
.1 cwt.
These substances in a powdered state are intimately mixed with the solid sewage
matter and the mixture allowed to dry, it may be by exposure to dry air at the
ordinary temperature, or upon a heated floor, the mixture being constantly stirred.
When dry the mixture is pulverized by any suitable means, as for example edge
runners, and is then ready for use as a manure. Such manure whilst possessing
valuable fertilizing properties, will destroy all insect life including phyloxera and
typula grub.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1
Trastinae amodo cATIANA
11
5

page_text: and obtaining a purified and disinfected effluent, by intimately mixing the crude
sewage with sulphate of lime, chloride of sodium, nitrate of lead, borax, common
alum and nitrate of potash, with or without addition of salicylic acid, hydrochloric
acid and caustic potash, allowing the treated sewage to rest in a settling tank, and
running off the supernatant liquid substantially as herein described.
2. The herein described method of preparing sewage for use as a manure, by
precipitating solid matters from the crude sewage, filtering the resulting sewage
sludge, mixing the solid sewage matter thus obtained with sulphate of lime, carbonate
of lime, chloride of sodium, sulphur, borax and magnesite, and drying and pulverising
the mixture substantially as herein described.
Dated this 20th day of Lul, 1801
1.
JOHN HARDWICK.
LOUIS ARTHUR NEWTON.
W. Lloyd Wise,
46, Lincoln's Inn Fields, London, W.C., Agent for the Applicants.