Improvements in the Treatment of Sewage and other Foul Waters of analogous nature for Effecting the Purification thereof.
Year: 1892

page_text: Date of Application. 13th Aug., 1892.
Complete Specification Left, 13th May, 1893-Accepted, 8th July, 1893
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of Sewage and other Foul Waters
of analogous nature for Effecting the Purification thereof.
I CHARLES DREYFUS of The Clayton Aniline Co. Ld. of Clayton near
Manchester in the County of Lancaster Chemist do hereby declare the nature of
this invention to be as follows:-
My invention relates to the purification of sewage and foul waters of an
analogous nature (I will refer to it as sewage) and includes operations of precipi-
tation and filtration. The precipitation is caused by adding to the sewage before
it enters the settling tanks a solution of basic persulphate of iron (which may be
prepared from the acid product from the purification of crude naphtha or light or
exude petroleum or light mineral oil and from the nitrification of organic substances
by dilution and treatment with waste iron from the manufacture of amido compounds
and an oxidising agent) and a small proportion of a milk of lime. The sewage then
passes through settling tanks where, owing to the nature of the precipitants used,
the impurities settle rapidly. For filtration I use a filter bed composed of the
oxide of iron hereinafter mentioned or composed partly of the said oxide for
instance at the bottom of gravel and above of a mixture of gravel and the said
oxide of iron and a top layer of sand. The oxide of iron which I use is made by
utilizing the iron residue or waste iron derived from aniline works or works where
iron is used for reducing nitro compounds into amido compounds. Such residue
'consists mainly of a mixture of metallic iron, hydrated oxide of iron and, after it
has stood in the air for some time, of other oxygen combination of iron.
I allow it to dry in the air and calcine it in ordinary reverberatory furnaces and
it is this calcined oxides of iron that I use for my filters.
++
The treated sewage is further purified by passing through this filtering medium
and the effluent obtained is very clear and comparatively pure.
·Dated this 13th day of August 1892.
U
J. H. JOHNSON & Co.,
47, Lincoln's Inn Fields, London, W.C., Agents.
COMPLETE SPECIFICATION.
Improvements in the Treatment of Sewage and other Foul Waters
of analogous nature for Effecting the Purification thereof.
I CHARLES DREYFUS of The Clayton Aniline Company Limited of Clayton
near Manchester in the County of Lancaster Chemist do hereby declare the nature
of my invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement :-
A
My invention relates to the purification of sewage and foul waters of an
analogous nature (I will refer to it as sewage) and includes operations of precipi-
tation and filtration. The precipitation is caused by adding to the sewage before
it enters the settling tank or tanks or when in the settling tank or tanks a solution
of basic persulphate of iron (which may be prepared from the acid product from
the purification of crude naphtha or light or crude petroleum or light mineral oil
and from the nitrification of organic substances by dilution and treatment with
waste iron from the manufacture of amido compounds and an oxidising agent) and
a small proportion of a milk of lime. The proportions of the solution of basic per-
sulphate of iron which I have found to answer best are according to the nature of
the sewage to be treated corresponding to a quantity calculated as metallic
מל

page_text: iron (Fe) of 2 to 5 grains of metallic iron per gallon of sewage to be treated or 20
to 30 cwts. of a solution of basic persulphate of iron at 100 Twaddle per million
gallons of sewage to be treated and from 5 to 10 cwts. of lime to the above quantity
of sewage. I prefer adding the lime first and in such quantity as to render the
sewage faintly alkaline the basic persulphate of iron is added afterwards and the
precipitation of the impurities takes place.
When the sewage is sufficiently alkaline (as is frequently the case) the use of
lime may be dispensed with. In the settling tank or tanks owing to the nature of
the precipitants used, the impurities settle rapidly. For filtration I use a filter bed
composed of the oxide of iron hereinafter mentioned or composed partly of the said
oxide for instance at the bottom of gravel and above of a mixture of gravel and the
said oxide of iron and a top layer of sand. The filters may be constructed in any
usual or suitable manner I prefer however to use such as are of a depth of about
3 feet only the bottom layer or stratum being of very coarse gravel to a depth of
6 inches to 9 inches the next layer or stratum of 6 inches of less coarse gravel the
third layer of 6 or 9 inches of still less coarse gravel and then a layer of one foot of
my filtering material either alone or mixed with fine gravel and finally a top layer or
stratum of coarse sand. I do not confine myself to the use of gravel and sand as
other like materials such as cinders coke or the like may be used. The oxide of
iron which I use is made by utilising the iron residue or waste iron derived from
aniline works or works where iron is used for reducing nitro compounds into amido
compounds. Such residue consists mainly of a mixture of metallic iron, hydrated
oxide of iron and, after it has stood in the air for some time, of other oxygen
combinations of iron which I have found to be principally magnetic oxide of iron.
I allow it to dry in the air and may calcine it in ordinary reverberatory furnaces
and it is these dried or calcined oxides of iron that I use for my filter.
The treated sewage is further purified by passing through this filtering medium
and the effluent obtained is very clear and comparatively pure.
The filters described may also be used for filtering sewage or the like from which
solid matter has been precipitated by other precipitants than those described or
from which the solid matter has simply been first allowed to settle without the use
of special precipitants.
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. In the treatment of sewage and other foul waters of analogous nature for
effecting the purification thereof effecting precipitation by means of a solution of
basic persulphate of iron with or without milk of lime and then filtering through a
filter consisting of or containing dried or calcined oxide of iron substantially as
herein before explained.
2. In the treatment of sewage and other foul waters of analogous nature for
effecting purification thereof first precipitating impurities by means of basic per-
sulphate of iron with or without milk of lime and then filtering the supernatant
liquid through a filter composed of or containing dried or calcined iron residue or
waste iron derived from aniline works or works where iron is used for reducing
nitro compounds into amido compounds substantially as hereinbefore described.
3. The filtering of sewage (whether treated by the above basic persulphate of
iron and lime or by any other precipitant or after previous settlement only) by
passing it through a filter composed of, or containing calcined or dried iron residue
or waste iron derived from aniline works or works where iron is used for reducing
nitro compounds into amido compounds substantially as hereinbefore described.
This 19th 31000