IMPROVEMENTS IN TREATING SEWAGE AND OTHER IMPURE OR POLLUTED WATERS
Year: 1875

page_text: LETTERS PATENT to Alexander Melville Clark, of 53, Chancery Lane,
.
in the County of Middlesex, Patent Agent, for the Invention of
"IMPROVEMENTS IN TREATING SEWAGE AND OTHER IMPURE OR POLLUTED
WATERS."-A communication from abroad by Paul Albert Bonnard,
of Paris, France.
Sealed the 29th February 1876, and dated the 8th September 1875.
PROVISIONAL SPECIFICATION left by the said Alexander Melville
Clark at the Office of the Commissioners of Patents, with his
Petition, on the 8th September 1875.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, Patent Agent, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN TREATING SEWAGE AND OTHER
IMPURE OR POLLUTED WATERS," to be as follows:-
This Invention relates to a process' of purifying, clarifying, and
rendering inodorous foul water from various sources, but especially
sewage water and the impure waters from manufactories; it may also be

page_text: 4th. When the waters to be treated contain but little ammonia, but
are chiefly contaminated by the presence of urea or of organic matters,
it is in certain cases advantageous to destroy these impurities by the
action of nitrous or hyponitric acids, or of nitrous vapors resulting from
certain industrial reactions, and in which the nitric acid is in part
deoxidised, or of soluble nitrites. In some cases this reaction may be
employed very efficaciously to complete the purification already effected
by the first reagents specified. When I employ at same time a soluble
phosphate and a salt of magnesia to produce a precipitate of double
phosphate of ammonia and of magnesia, which takes up all the ammonia
that is in solution in these liquids, it may happen that a part of the
double phosphate thus formed remains in solution in the clarified waters
(since one part of ammonio-magnesian phosphate dissolves in fifteen
thousand parts of water), and to avoid the loss which might result from
this solubility, slight though it may be, the liquids may be filtered on
dolomite (double carbonate of magnesia and lime), which retains all tho
phosphate dissolved.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Alexander Melville Clark in the Great Seal Patent
Office on the 4th March 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ALEXANDER
MELVILLE CLARK, of 53, Chancery Lane, in the County of Middlesex,
Patent Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of September, in the
year of our Lord One thousand eight hundred and seventy-five, in
the thirty-ninth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Alexander Melville Clark,
Her special license that I, the said Alexander Melville Clark, my
executors, administrators, and assigns, or such others as I, the said
Alexander Melville Clark, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time
and at all times thereafter during the term, therein expressed,
should and lawfully might make, use, exercise, and vend, within

page_text: the United Kingdom of Great Britain and Ireland, the' Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN TREATING
SEWAGE AND OTHER IMPURE OR POLLUTED WATERS," a communication to
me from abroad by Paul Albert Bonnard, of Paris, France, upon
the condition (amongst others) that I, the said Alexander Melville
Olark, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should parti-
cularly describe and ascertain the nature of the said Invention, and
in what manner the same was to be performed, and cause the same
to be filed in the Great Seal Patent Office within six calendar.
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said Alexander Melville Clark, do hereby
declare the nature of the said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement, that is to say :-
-
'
This Invention relates to a process of purifying, clarifying, and
rendering inodorous foul water from various sources, but especially
sewage water, and the impure waters from manufactories. It may also
be applied for purifying river water contaminated with organic matters.
The process is based upon the employment of certain chemical reagents
hereafter specified, and which may be employed together or separately.
The method of treatment and the reagent employed vary according to
the nature and condition of the impurities which it is desired to eliminate
or destroy, and also according to the precise object to be attained, that
_is_to say, according-to-whether-it-is-merely-intended-topurify-the-waters=
without seeking to obtain utilizable products therefrom, such as
manures, or whether on the other hand it is desired to obtain marketable
manures.
.
1st. Aluminate of soda. This salt precipitates the azotized organic
matters forming with these substances, and also with the coloring
matters species of lakes. It is especially useful for the treatment of
waters from manufactories, and it is well adapted for use with chloride
of calcium.

page_text: 2nd. Aluminate of soda, and afterwards phosphoric acid or an alkaline
phosphate, or a soluble phosphate of lime or of magnesia. In this case
insoluble phosphates of alumina, lime, or magnesia are formed, which
unite with the organic matters in suspension with a part of those which
are in solution, and with the coloring matters, whilst there remains in
solution an ammoniacal salt and an alkaline phosphate, or it may be a
phosphate of ammonia. If to these liquids a soluble salt of magnesia
be then added a precipitate of double phosphate of ammonia and
magnesia is obtained.
3rd. Phosphate of soda and a soluble salt of magnesia, giving pre-
ference more particularly to the tribasic phosphate of soda, mixed
chemically or mechanically with phosphate or oxide of iron. In the
latter case it is often of advantage to employ as the soluble salt of
magnesia a certain quantity of the acid phosphate of this base. As all
these reagents are soluble they are mixed with the water to be purified,
either by distributing them in the tanks or reservoirs in which the
waters are contained, or by supplying them to the flowing water in
quantity proportionate to the volume and the degree of impurity of the
|latter, after which the precipitates are allowed to subside in tanks and
the liquid subsequently drained off, but the separation is much more
quickly effected by employing Parrot's filtering tanks.
4th. When the waters to be treated contain but little ammonia, but
are chiefly contaminated by the presence of urea or of organic matters,
it is in certain cases advantageous to destroy those impurities by the
action of nitrous or hyponitric acids, or of nitrous vapours resulting from
certain industrial reactions in which the nitric acid is in part deoxidised,
or of soluble nitrites. In some cases this reaction may be employed
very efficaciously to complete the purification already effected by the
first reagents specified. When I employ at same time a soluble
phosphate and a salt of magnesia to produce a precipitate of double
phosphate of ammonia and magnesia, which takes up all the ammonia
that was in solution in the liquids, it may happen that a part of the
double phosphate thus formed remains in solution in the clarified waters
(since one part of ammonio-magnesian phosphate dissolves in fifteen
thousand parts of water), and to avoid the loss which might result from
this solubility, slight though it may be, the liquid may be filtered on
dolomite (double carbonate of magnesia and lime) which retains all the
nhosphate dissolved.
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