An Improved Process for Rendering Drinking Water Free from Germs.
Year: 1897

page_text: Date of Application, 4th Mar., 1897-Accepted, 8th May, 1897
COMPLETE SPECIFICATION.
An Improved Process for Rendering Drinking Water Free from
Germs.
I, PAUL ALTMANN of Pankow, near Berlin in the Empire of Germany,
Apothecary, 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 method hitherto most frequently employed for rendering water containing
bacteria free from germs and thereby potable consisted in filtration through bodies
adapted to retain the germs. All the numerous forms of filter constructions
hitherto employed however have either not acted at all or only under certain
conditions, which, as is wellknown, are never actually fulfilled, or have only
exhibited a partial action. The attempts moreover hitherto made to render
drinking water free from germs and suitable for drinking purposes by the addition
of chemicals have not attained their, object. It is indeed not difficult to render
water free from germs by the addition of chemicals but it is almost impossible to
again remove the disinfecting material from the water or to render it non-
deleterious and unnoticeable. The final result therefore, that is the rapid
obtaining of a water having a good appearance, has hitherto in almost every case
been a negative one.
This invention relates to a process for killing rapidly and safely in any water
charged with bacteria all the pathogenetic germs shown to exist in water and to
again rapidly make the water equally drinkable.
The killing of the germs is in this process obtained by adding a given quantity
of bromine to a given quantity of impure water. This substance has such an
action that even after five minutes all the germs contained in the water are
destroyed. The bromine added is then rendered nondeleterious by the addition
of a quantity of ammonia suitably proportioned to absorb the bromine, in con-
sequence of which a clear and germless water results. From the action of
ammonia on bromine, there results hypobromide of ammonia and ammonium
bromide; the latter results from the former. The quantity of bromine employed
is very moderate, '06 grammes per litre of water will suffice.
The bromine is preferably employed in the form of bromide of potash solution
and preferably as a 20% solution. 2 cubic centimetres of this solution will
suffice to sterilise a litre of river water in five minutes. If very strong ammoniacal
(marsh) water or water containing a large quantity of lime is to be rendered free
from germs, part of the bromine added will, before it can exert a disinfecting
action, itself combine with the ammonia or the lime salts. It is therefore
necessary in such water to add bromine until a slight yellow colour which lasts
about half a minute results in the water. For removing, the 2 cubic centimetres
of bromide of potash solution, an equal quantity of 9% ammonia is employed.
The two liquids must be employed precisely in the proportions given to one
another, although neither a very small excess quantity of free bromine nor of free
ammonia will be found unpleasant in taste. If a special (rather more than *2 cubic
centimetres) bromine of potash solution has been employed, correspondingly more
ammonia must be added. The taste of the water obtained hardly differs from
that of the original. The colour is absolutely clear. The amount of bromine

page_text: salts (0708 grammes per litre of water) is so small that it remains without
any influence on the taste.
In order to utilise this method as a thoroughly certain and non-deleterious
means of purifying water, and to obtain a safe dose, it is preferable to supply the
bromine solution commercially in given measured quantities. For this purpose
small glass vessels or the like are preferably sold filled with certain or given
quantities of bromine or ammonia, and sealed down, or drop bottles with exactly
equal dropping devices may be employed, which render it possible to deliver an
exact quantity of the measured liquid. For the purpose of rendering larger
quantities of water free from germs the measured off liquids may be added
thereto by means of pipettes or like devices.
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:-
A process for rendering drinking water free from germs, characterised by the
addition to the water of an exactly measured quantity of bromine solution, and
then an equally exactly measured quantity of ammonia solution, with the object of
killing any bacteria contained in the water by means of the bromine and rendering
the bromine again non-deleterious by means of the ammonia, substantially as
described.
ed this 3rd day of March 1897.
WM. P. THOMPSON & Co.,
Of 6 Lord Street, Liverpool, Agents for the Applicant.