Improvements in the Clarification or Purification of Sewage and other Foul Waters of Analogous Nature.
Year: 1889

page_text: Date of Application, 26th Apr., 1889
Complete Specification Left, 26th Feb., 1890-Accepted, 29th Mar,, 1890
TRUTTOIONAL DEPOTICATION.
Improvements in the Clarification or Purification of Sewage and
other Foul Waters of Analogous Nature.
I, CHARLES HENRY HARVEY of 5, Great Queen Street, in the County of Middlesex
General Manager of and for the benefit of the Barry Patent Manure Company
Limited, do hereby declare the nature of this invention to be as follows:
Our invention consists in the use of acid ferric salts prepared from waste sulphide
of iron, in conjunction with an alkaline earth.
The waste product we propose to use to prepare the acid ferric salts is a sulphide of
iron essentially, the sulphur of which is extracted in the ordinary or any other manner
and replaced by absorption, when exposed to the atmospheric air, by oxygen to its
fullest extent.
We dissolve the oxide of iron thus obtained (sesqui-oxide of iron) in a suitable acid,
say hydrochloric or sulphuric acid, or a mixture of the two, or of one of these and
any other suitable acid, so as to produce an acid ferric salt. The acidity should not
exceed from one to three per cent., more or less, of the quantity used.
The reason for this excess of acidity is, that when in this state, the ferric salt or
salts exercise a coagulative influence on the soluble albuminous matters and cause
their precipitation to a considerable extent.
This said ferric salt or salts will be decomposed by the addition of alkaline earth or
earths forming ferric hydrate, a body of considerable oxidising power, and which is
easily deprived of its oxygen when in contact with animal or vegetable matters,
susceptible to oxidation, such as are found in sewage.
The coagulation of the soluble albuminous matters by and with the reagents we
propose to employ, will mechanically carry with it the whole of the suspended matter.
contained in the sewage, producing a clear neutral effluent, and a sludge containing
valuable fertilizing properties, rich in nitrogen and including phosphates, lime
salts, etcetera. These several constituents are well known as important manurial
agents.
In conjunction with acid ferric salts we use an alkaline earth as before stated, which
may be carbonate of the earth metals, barium, strontium, calcium, magnesium, or any
mixture or combination of any or all of them.
We prefer to take impure sulphide of lime, which contains an alkaline earth;
namely, carbonate of calcium, and sulphur compounds of calcium along with different
other matters; before using same we oxidise these sulphur compounds to their fullest
extent, by exposing them, under shelter, to the action of the atmosphere for a period
of three or four weeks.
Other oxidised sulphur compounds of lime but containing carbonate, can be used
in addition to the ferric salt, and for ferric salts, the acid waters from copper precipi-
tating works or other waste waters strong in ferric salts can be in part utilized.
Doted this 24th day of Anril 1889
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.

page_text: COMPLETE SPECIFICATION.
Improvements in the Clarification or Purification of Sewage and
other Foul Waters of Analogous Nature.
I, CHARLES HENRY HARVEY, of 5, Great Queen Street, in the County of Middlesex,
General Manager of and for the benefit of the Barry Patent Manure Company,
Limited, 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 :-
Our invention consists in the use of acid ferric salts prepared from waste sulphide
of iron, in conjunction with an alkaline earth.
The waste product we propose to use to prepare the acid ferric salts, is a sulphide
of iron originally, but the sulphur of which is extracted in the ordinary way or any
other manner and replaced by oxygen.
We dissolve the oxide of iron thus obtained, (sesqui-oxide of iron) in hydrochloric
acid, sulphuric and other acids will answer to some extent, but we prefer hydro-
chloric. In this way we form a slightly acid ferric salt, but the free acid should not
exceed three per cent. of the mass. From this we form a solution of ferric salt
slightly acid of 55 degrees Twaddle, that is 1.275 specific gravity (hereafter called
solution "A"). We now take Le Blanc soda waste, or lime that has been used in
chemical operations to absorb sulphur and cyanides and expose this under shelter to
the atmosphere for three or four weeks, till well oxidised, this is ground to a powder
(hereafter called powder "B"). To every 1,000,000 gallons of sewage of a town,
using the water closet system and a single drainage system for both house sewage and
storm water, we take a thousand pounds of powder "B" and 62 gallons of
solution "A" and add both to the solution at the same time and at points close
together.
The two mutually re-act on each other and on the sewage, causing a wonderful
clarification and purification of the latter.
The manufacture of solution "A" is conducted in stone tanks provided with
unperforated vulcanite steam coils, these being the best and cheapest materials we have
found capable of withstanding the action of the hot acid and ferric salt.
The object of the excess of acidity in solution "A" is that, when in this state, the
ferric salt or salis exercise a coagulative influence on the soluble albuminous matters
and cause their precipitation to a considerable extent.
This said ferric salt or salts is decomposed by the addition of alkaline earth or earths
forming ferric hydrate. This is a body of considerable oxidising power, and which is
easily deprived of its oxygen when in contact with animal or vegetable matters,
susceptible to oxidation, such as are found in sewage.
The coagulation of the soluble albuminous matters by and with the re-agents we
propose to employ, will mechanically carry with it the whole of the suspended matter
contained in the sewage, producing a clear neutral effluent, and a sludge containing
valuable fertilising properties, and having among its ingredients nitrogenous com-
pounds, phosphates, lime salts, etcetera. These several constituents are well known as
important manurial agents.
In the manufacture of this solution, however, other sources of ferric chloride can
be employed, thus the waste acid solutions of copper works can be used to a con-
siderable extent, all indeed that is required is to get a given amount of ferric solution
of about specific gravity 1.275 or a corresponding and equivalent amount of a different
strength.
For other sewage than that described above, varying amounts of solution "A" and
powder "B" are employed, but the exact amount most useful can, in cach case, be
ascertained by experiment or by adding the two a little at a time till the effluent is
clear.

page_text: 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. The process of treating sewage, which consists in dissolving iron oxide in hydro-
chloric acid, also drying, allowing to oxidise, and pulverising lime that has been used
to absorb sulphur and cyanogen compounds in chemical or gas purifying operations,
and adding the ferric salt and the lime compound powder to the sewage in such
manner that they shall mutually re-act on each other and on the sewage.
2. In the purification of sewage, the manufacture and use of a ferric salt solution
by dissolving burnt pyrites in hydrochloric acid and the addition of this salt to
sewage in combination with lime compounds, substantially as described.
3. The manufacture and use, in the purification of sewage, of a lime compound rich
in cyanogen and oxidised sulphur compounds, substantially as described, and its
application to sewage in combination with the ferric salt.
Dated this 5th 1
1800
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for Applicant.