Improvements in the Purification of Sewage.
Year: 1893

page_text: Date of Application; 2nd Oct:, 1893
Complete Specification Left; 2nd July, 1894-Accepted, 4th Aug., 1894
PROVISIONAL SPECIFICATION:
Improvements in the Purification of Sewage.
We, LEONARD ARCHBUTT, of 11 Charnwood Street, Derby, Analytical
Chemist, and RICHARD MOUNTFORD DEELEY, of 10 Charnwood Street, Derby,
Engineer, do hereby declare the nature of this invention to be as follows:-
89
In our previous Specifications Nos. 19829", 19830", 3051", 11708" and 1791
apparatus and methods have been devised for the purification of hard or impure
water by chemical precipitation in which rapid clarification of the purified water is
effected by stirring up some of the precipitate produced in former operations and
mixing it with the turbid water; and in order to neutralize any free caustic alkali
which may remain after purification and render the water unfit for many purposes
we have described the treatment of the clarified water with fuel gases. The
effluent from a plant treating sewage in this manner, although bright and clear
still retains in solution albuminoids which are incapable of removal by chemical
precipitation but which by the agency of the nitrifying bacteria are readily split
up and converted into harmless compounds, this secondary purification is brought
about by passing the clear bicarbonated effluent through a filter bed of sand,
cinders, loam, or other suitable material.
In carrying out the process we first convey the impure water into a suitable
tank, we mix it with the necessary chemicals for precipitation either as it flows
into the tank or after the tank is full, we agitate it with the precipitate of previous
operations by means of a current of air or other means, and we then allow the
liquid to settle for 30 to 60 minutes when it will be quite clear and bright. The
clear liquid is then drawn off through a pipe, tank or other apparatus in which it
is treated with fuel gases in sufficient quantity to convert all free alkali into
bicarbonate and it is afterwards passed on to a filter bed.
The treatment with fuel gases prevents the clogging of the filter which otherwise
would in some cases seriously interfere with filtration.
Dated this 30th day of September 1893.
L. ARCHBUTT.
R. M. DEELEY.
COMPLETE SPECIFICATION.
Improvements in the Purification of Sewage.
We, LEONARD ARCHBUTT, of 11 Charnwood Street, Derby, Analytical
Chemist, and RICHARD MOUNTFORD DEELEY, of 10 Charnwood Street, Derby,
Engineer, do bereby 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 :-
In our previous Specifications Nos. 19829", 19830", 3051", 11708" and 1791",
apparatus and methods have been described for the purification of hard or impure
water by chemical precipitation in which rapid clarification of the purified water
is effected by stirring up some of the precipitate produced in former operations and
mixing it with the turbid water; and in order to neutralize any free caustic alkali
which may remain after purification and render the water unfit for many purposes
we have described the treatment of the clarified water with fuel gases.
effluent from a plant treating sewage in this manner, although bright and clear, still
Price 8d 1
The

page_text: retains in solution albuminoids which are incapable of removal by chemical
precipitation but which by the agency of the nitrifying and other bacteria are
readily split up and converted into harmless compounds, this secondary purification
is brought about by passing the clear bicarbonated effluent through a filter bed of
sand, cinders, loam, or other suitable material.
In carrying out the process we first convey the impure water into a suitable tank,
we mix it with the necessary chemicals for precipitation either as it flows into the
tank or after the tank is full, we agitate it with the precipitate of previous
operations by means of a current of air or other means, and we then allow the
liquid to settle for 30 to 60 minutes when it will be quite clear and bright. The
clear liquid is then drawn off through a pipe, tank or other apparatus in which it is
treated with fuel gases in sufficient quantity to convert all free alkali into bicarbonate
and it is afterwards passed on to a filter bed.
The treatment with fuel gases not only prevents the clogging of the filter which
otherwise would in some cases seriously interfere with filtration but it promotes the..
development of the micro-organisms.
The filter bed may be composed of coarse gravel and sand arranged as follows:-
At the bottom, 8 inches of coarse gravel in which drain pipes are laid for conveying
away the filtered effluent, above that five inches of fine pea gravel; and on the top.
five feet of coarse mortar sand. One or more of such filter beds are provided for
each precipitation tank, and the clarified and bicarbonated effluent from each tank"
in rotation is allowed to flow on to the filter beds in rotation, the area of the filter"
beds being so proportioned that the tankful of effluent discharged upon each
particular bed or set of beds will have sunk into the sand before the next tankful is
ready to be discharged, and thus each bed will be kept properly aerated.
In starting a new set of filter beds the maximum degree of purification will not
be reached until a sufficient time has elapsed for the nitrifying and other organisms
to have multiplied and fully established themselves. It is obvious that other
filtering media, such as those known as polarite, magnetic carbide &c., may be used
in conjunction with the sand.
When such filtering materials are used the sewage may be run continuously upon
the same bed or set of beds, an occasional stop only being required in order that
the filtering surface may be cleansed. Or air may be forced continuously into a
suitably formed bed of sand and gravel, and the sewage together with the air
allowed to pass continuously downwards through the bed. The effluent from.our
precipitation tank is peculiarly suitable for all such filters as it is almost perfectly
free from suspended matter and contains no free alkali except the small quantity
existing entirely as bicarbonate.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The purification of impure water by the several operations consisting in
precipitating with lime or the like, agitating with a previous precipitate, then
bicarbonating the liquid and finally passing the effluent water through a filter bed
so worked substantially as described as to effect the destruction of albuminoid
matters.
Dad thin 20th Jan of Tune 1904
LEONARD ARCHBUTT.
R. M. DEELEY.