AN IMPROVED METHod of PURIFYING DRAINAGE WATERS AND SEWAGE
Year: 1885

page_text: I MARTIN NAHNSEN, Chemist of Schönebeck-a-d-Elbe in the Kingdom of Prussia
do hereby declare the nature of the said invention for "AN IMPROVED METHod of
PURIFYING DRAINAGE WATERS AND SEWAGE" to be as follows:-
This invention has for object to utilise the peculiar effect which I have found
is exercised by pulverised phosphoric slag on sewage and drainage waters of all
degrees of foulness.
'
The phosphoric slag when mixed with the foul water acts so as to clarify it
mechanically while the constituent parts of the slag exercise a peculiar chemical
effect, the result being that such a precipitation takes place as to leave the foul
water treated nearly colourless.
The chemical action of the phosphoric slag is brought about partly by reason
of its iron and protoxide of manganese contents which in the presence of alkali
especially of lime combine together sulphide of hydrogen and sulphide of ammonium,
aud partly by reason of its contents of the oxides of the said metals which pre-
cipitate colouring matters and other organic substances in solution, especially also
nitrogenous substances and ammonia.
In practice the phosphoric slag is disintegrated in the presence of water until it
reaches a state of pulp when it is mixed with the sewage or drainage water to be
purified in a proportion or quantity corresponding to the degree of foulness of the
same. As the slag pulp reacts alkali wise and accordingly the treated water after
clarification shews alkiline reaction, it is advisable, in order to remedy this by the
separation of carbonate of calcium, to precipitate the excess lime by means of
gelatinous or soluble hydrate of silicic acid. In this way the water is subjected
to an additional process of purification in which the quickly setting silicate of lime
precipitate hereby formed also precipitates the remainder of the organic matters
which may not have been previously separated.
The precipitate is phosphoric slag enriched with organic and nitrogenous
substances, yielding a valuable manure.
1
100
EMIL CAPITAINE,
Agent.

page_text: An Improved Method of Purifying Drainage Waters and Sewage.
1
I, MARTIN NAHNSEN, Chemist, of Schönebeck-a-d-Elbe in the Kingdom of
AN IMPROVED
Prussia do hereby declare the nature of the said invention for
METHOD OF PURIFYING DRAINAGE WATERS AND SEWAGE" and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:―
This invention has for object to utilise the peculiar effect which I have found is
exercised by pulverised phosphoric slag on sewage and drainage waters of all
degrees of foulness.
The phosphoric slag when mixed with the foul water acts so as to clarify it
mechanically while the constituent parts of the slag exercise a peculiar chemical
effect the result being that such a precipitation takes place as to leave the foul
water treated, nearly colourless.
The chemical action of the phosphoric slag is brought about partly by reason
of its iron and protoxide of manganese contents which in the presence of alkali
especially of lime combine together sulphide of hydrogen and sulphide of ammonium,
and partly by reason of its contents of the oxides of the said metals which pre-
cipitate organic colouring and other organic dissolved matters especially also
nitrogenous substances and ammonia.
These actions are to be observed in a still higher degree when in addition to the
phosphoric slag a dissolved magnesium argillaceous earth, iron, or manganese salt
is added to the foul water, the earthy base of the phosphoric slag present in a
somewhat compact form then acts, the lime separating on the base of the added
salt, mixtures are formed of gelatine like magnesium-argillaceous earth, iron, or
hydro oxide of manganese precipitates with the partially dissolved and disintegrated
phosphoric slag and then the aforesaid constituent parts of the phosphoric slag in
conjunction with these gelatinous precipitates operate in the indicated direction, the
result is that a real cleansing of the foul water is effected on the one hand, and on
the other band a valuable manure is produced.
In practice the phosphoric slag is disintegrated in the presence of water until it
reaches a state of pulp when it is added to the sewage or drainage water to be
purified in a proportion or quantity corresponding to the degree of foulness of the
same. In the case of an average contents of 200 milligrammes of dissolved matters
and 500 milligrammes of suspended matters per litre from one to two kilogrammes
The salt
would be sufficient for the process of purification per cubic metre.
solutions may be added to the foul water either before or after the addition of
the phosphoric slag pulp. If such salt solutions are omitted the alkaline reaction
of the foul water treated with phosphoric slag may be removed by the addition of
silicic acid hydrate. The water is hereby subjected to a further purifying process
in which the quickly setting silicate of line thus formed also precipitates residues
of organic substances which may not have been previously separated.
The precipitate is phosphoric slag enriched with organic and nitrogenous sub-
stances and yielding a valuable manure.

page_text: Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The process of purifying drainage waters and sewage by the application
of phosphoric slag alone or in combination with soluble salts of magnesium,
argillaceous earth, iron and manganese, substantially as described.
2. The process of purifying drainage waters and sewage by the use of phosphoric
slag and soluble silicic acid hydrate substantially as described.
3. The process for the production of manure from phosphoric slag and dissolved
organic and nitrogenous constituent parts of drainage waters and sewage by
precipitating such parts by means of phosphoric slag substantially as described.
EMIL CAPITAINE,
Agent for the Inventor.