Improvements in the Treatment of Sewage and Sewage Matters and in the Production of Fertilizing Products therefrom.
Year: 1889

page_text: Date of Application, 21st Nov., 1889
Complete Specification Left, 16th Sept., 1890-Accepted, 18th Oct., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Sewage and Sewage Matters
and in the Production of Fertilizing Products therefrom.
I, WILLIAM BATH KEMSHEAD, of Avondale, Graham Road, Mitcham, in the County
of Surrey, Professor of Chemistry, Science and Mathematics, do hereby declare the
nature of this invention to be as follows:-
This invention relates to the treatment of sewage and sewage matters and to the
production of fertilizing products therefrom.
I first disinfect the sewage matter either by known means or by means of a chemical
process of my invention. I then allow the surface or storm water to run or filter off
in a perfectly innocuous condition; the substance then left is technically called
"sludge." I treat it with a purifying chemical and then thoroughly incorporate it
with loam earth of a suitable character and afterwards press it into cakes and dry it in
a suitable manner for package and sale.
Dated the 21st day of November 1889.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Sewage and Sewage Matters
and in the Production of Fertilizing Products therefrom.
1, WILLIAM BATH KEMSHEAD, of Avondale, Graham Road, Mitcham, in the County
of Surrey, Professor of Chemistry, Science and Mathematics, 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 relates to the treatment of sewage and sewage matters and to the
production of fertilizing products therefrom.
Sewage consists of decaying organic substances (chiefly foecal) waste industrial
products and a large quantity of surplus water. The salts which are of the most
value for fertilizing purposes are almost all soluble in water, for example, the nitrates
with the exception of basic salts are all soluble; the salts of sodium and ammonium
are all soluble, while those of potassium are likewise soluble with the exception of the
arsenite which will be rarely and should never be found in sewage.
The water therefore tends to dissolve out these valuable salts, which are carried
down to the river or outlet rendering the water impure, unfit for domestic use and
poisonous to animal and vegetable life. The existing methods of dealing with sewage,
almost without exception, precipitate by means of lime, generally caustic lime, .
decomposing the carbonates, sulphates and phosphates and throwing down the insoluble
carbonate, sulphate and phosphate of lime, in a form useless as a manure and yet leaving
the surplus water in a deleterious condition.
According to my invention I first disinfect the sewage whereby I render it
harmless for subsequent manipulation, I fix the maximum quantity of the soluble
salts, which I retain still in a soluble form in the resulting product, and the surplus
or effluent water is given off in practically a neutral condition.
The sewage is received in a circular tank and is there disinfected together with
the water by the addition of a disinfecting powder known in commerce as "Smiths
disinfecting cleansing powder." I may remark here that any disinfecting powder may
be used provided it contains neither lime, chlorine, nor carbolic acid.
The powder in the proportion of about 1 lb. to about 3 or 4 gallons of sewage,
D

page_text: is well mixed by means of an agitator, and the whole allowed to stand for about
2 or 3 hours. The excess or surplus water is then filtered off by the ordinary
means of filtration. This water is perfectly innocuous and might be at once run into
a stream but as it contains a slight portion of the ammoniacal salts in solution I
prefer to use it for irrigating a sewage farm.
The quantity of disinfecting powder will vary within narrow limits according to
the state of the sewage. After the water has been run off there remains what is
technically called "sludge." This I treat with the following chemical substances for
producing fertilizing products.
organions of 10. of Surphate of potassium and about
1 lb. of sulphate of ammonia (the refuse from gas works is especially suitable) and-
thoroughly well mix.
2. FOR CEREAL CROPS.
With the same amount of sewage 1 employ about 1 lb. of soluble silicate of
potassium in addition to the sulphate of potassium and the sulphate of ammonia.
The product thus obtained by one or other of these admixtures should then be
thoroughly mixed by means of an agitator with fine sifted loam earth, or peat earth,
or sweepings from macadamized roads, or sweepings from gravel-made roads and
when of a suitable consistency made-into cakes of a convenient size, stacked under
a shed and dried like bricks, or by a blowing fan or other suitable means. When
dry, the cakes can be reduced to powder by an edge runner or other suitable
means. My fertilizing product is then ready for packing in tins or in any other
convenient manner.
The value of the earths for mixing with the sewage is strictly-in the order in
which I bave enumerated them, loam earth being the most and gravel dust the least
valuable; but in all cases they should be as free from lime as possible.
In some cases instead of mixing the compound of sludge and sulphates or of
sludge sulphate and silicate with loam earth, peat earth or sweepings as herein before
described I mix the compound with my fertilizing product which can be utilized
more than once as an absorbent of the sewage whereby I effect an economy at the
same time increasing the value of the resulting product as a fertilizer by obtaining it
in a more concentrated and richer form.
Having now particularly described-and-ascertained-the_nature_of_my_said_inven-
tion and in what manner the same is to be performed I declare that what I
claim is
(1.) A process of treating sewage and the like and the production of fertilizing
products therefróni such process consisting in first disinfecting the sewage, running
off the surplus water and mixing the resulting sludge with sulphate of potassium and
sulphate of ammonia and in some cases adding soluble silicate of potassium in about
the proportions mentioned then incorporating the mixture with finely sifted loam
earth, peat earth or road sweepings and drying it by suitable means the resulting
product being afterwards reduced to powder, substantially as and for the purpose
herein before described.
(2) The manufacture of fertilizing products substantially as hereinbefore
described.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.