A New or Improved Process for the Purification of Waste or Refuse Water from Sewers, Mills, Works, Factories, and the like.
Year: 1892

page_text: Date of Application, 23rd May, 1892-Accepted, 10th Sept., 1892
COMPLETE SPECIFICATION.
A New or Improved Process for the Purification of Waste or Refuse
Water from Sewers, Mills, Works, Factories, and the like.
I HEINRICH STIER, of Zwickau, Saxony, Engineer, 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:―
The purification of waste water from sewers, mills, works, factories and the like
such as hitherto carried on with the aid of lime, was not sufficient to enable the
same to meet the requirements expected therefrom, owing to the solubility of this
lime, and the purified water was unfit for most of the further uses for which it
was intended.
The greatest part of such waste or refuse water, in fact nearly the whole of that
which contains organic matter is, in consequence of its tendency to promote and
support decomposition, not only a great source of danger at a sanitary point of
view but is often the only reason why the water is sought to be purified or dis-
infected. Hitherto this water had resisted the simple means experimented upon
for the purpose of rendering it innocuous and prevented in most cases and
particularly owing to insolubility, too great an expenditure, and its strong noxious
properties, the use of such substances as tar, phenol and its derivatives, corrosive
sublimate and the like.
Therefore the separation in a simple and inexpensive manner of the dissolved
organic nitrogenous and non-nitrogenous matter from waste or refuse water formed
one of the most important problems of the present time.
While studying the antiseptic properties of the residual acids obtained in the
manufacture of tar and oil, I have been led by continuous experiments to the
discovery that these. acids which were hitherto a highly troublesome bye-product,
form in combination with argillaceous or other metallic earth a highly efficient
disinfectant and precipitant for this refuse or waste waters. For this purpose the
acids must be first mixed with substances containing argillaceous earth and sub-
sequently heated. As the mass is being dissolved a part of the antiseptic bodies
hitherto distributed in the acids, passes into the solution of the salt, while the
remaining part of these bodies is left undissolved and passes (probably with the
silicic acid of the argillaceous earth which separates under the action of heat) in an
extraordinarily fine state of division into the solution and may be used therewith
or separately. Solutions as well as residuums of these bituminous particles have
a similar action either for the purpose of disinfecting or precipitating dissolved
organic matter.
The insoluble residuum, as well as the silicic acid from the argillaceous clay,
adheres, together with the sulphate of lime which has been precipitated by the
'solution of aluminium salts from the refuse or waste water decomposed by lime, to
the light flaky and gelatinous precipitated organic matter and help as an additional
weight to draw the same quickly down thus effecting and promoting an almost
instantaneous purification.
The sediment produced resists decomposition at an ordinary temperature and
being thus unobjectionable at a sanitary point of view can be preserved for a
considerable period of time.
As I mix with the refuse or waste water a suitable quantity of the above
described compound composed of the residual acid produced in tar and oil mills
and of metallic salts (particularly aluminium) the following reaction take place.
When the waste water has been rendered alkaline by means of lime or alkalis,
sulphate of calcium and hydrate of aluminium are formed, and act as discolouring
means; while on the other side the dissolved and the divided antiseptic bituminous

page_text: particles act immediately they are precipitated upon the dissolved organic sub-
stances; the heavy sulphate of lime, the insoluble bituminous bodies or particles
and the silicic acid separated from the alumina enveloping or adhering to the
lighter organic matter separated, so as to precipitate the same rapidly and
form in a short time a thick durable deposit or sediment and a liquor which is
thoroughly clear, nearly pure, disinfected and unobjectionable at a sanitary point
of view.
When the refuse or waste water is not treated by lime, there is formed by the
argillaceous earth the salts and the dissolved antiseptic bodies a coagulation and a
precipitation of organic substance which is enveloped by the finely divided anti-
septic bituminous bodies and by the silicic acid of the precipitant and is rapidly
precipitated, thus yielding likewise a clear disinfected liquor.
The proportions of the various compositions and the degree of concentration
(sulphuric acid contents) of the waste and purifying acids and of the argillaceous
earth contained in the argillaceous substance used cannot be readily given in
figures.
A good result may be obtained by way of example by mixing equivalent masses
of waste acid and clay (according to their contents in SO³ and Al'O³) this
mixture being heated in any suitable manner.
According to the degree of concentration or to the aqueous contents of the acid
used and of the more or less readily refractory character of the clay, there follows
a reaction of the SO³ and the Al³O³ on the mass which reaction can be readily
noticed as the mass solidifies.
.
*།
Another good result may be obtained by way of example by mixing 17.5 of
waste acid (generally of from 40° to 42° B.) and 11 parts of clay (containing
about 28% of Al'O³) and heating the same in any suitable manner.
According to the more or less refractory character of the clay used the
reaction i.e. the action of SO³ on Al'O' follows at a temperature of from 120°
to 200° C. the mass which was first of a pasty consistence becoming solidified.
The product is used either in the above described state or after the water
of crystallization has been removed by further heating from the sulphate of
alumina.
•
The product contains a sulphate of alumina of a nature corresponding with that
of the mass of argillaceous earth and sulphuric acid used.
According to the nature of the waste or refuse water which requires to be
purified or disinfected from 1 to 2 parts of this product is mixed with from 500
to 2000 parts of the water; for the refuse of slaughter houses of hospitals or for
refuse highly charged with germs, more or less of the disinfecting mass may be
used; this mass being previously deposited in water and being used either with or
without chalk.
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 :-
A process for disinfecting or clarifying waste or refuse water from sewers, mills,
factories and the like by treating the same with a compound containing argillaceous
earth and the residual acids of tar and oil mills in the proportions indicated
substantially.as herein described and for the purpose set forth.
Dated this 23rd day of May 1899
HUGHES, SON & Co.,
38, Chancery Lane, London, Agents for the Applicant.