Treatment of Potable Waters by Alkalinisation and subsequent Neutralisation, with a view to their Sterilisation and Purifi- cation.
Year: 1894

page_text: Date of Application, 20th July, 1894
Complete Specification Left, 18th Apr., 1895-Accepted, 24th-May, 1895
Date u Application, uly, TOOT
Complete Specification Left, 18th Apr., 1895-Accepted, 24th May, 1895
PROVISIONAL SPECIFICATION.
Treatment of Potable Waters by Alkalinisation and subsequent
Neutralisation, with a view to their Sterilisation and Purifi-
cation.
I, HENRI JOSEPH NAPOLÉON BERGÉ, of Brussels, in the Kingdom of Belgium,
Professor of the University of Brussels, and Director of the Chemical Laboratory
of the Municipality, do hereby declare the nature of this invention to be as
follows:-
-
This invention has for its object to solve the great problem of the supply of
potable water to populous centres,.i.e. of water perfectly sterilised and deprived
of all impurities' by a process of great simplicity and of easy application con-
sisting essentially in the alkalinisation and ultimate neutralisation of the water
by an alkaline agent.
This process constitutes an absolute guarantee of purity in respect of the
typhoid and cholera bacilli whence may be deduced not only its infallible efficacy
but also its vast importance from the hygienic point of view and notably in
comparison with the action of other means of purification hitherto employed,
such for instance as filtration &c. which is quite inadequate inasmuch as most
filters favour the multiplication of micro-organisms without also taking into
account that even the best methods of filtration e.g. slow filtering through
porcelain and at low pressures, only give water which remains, sterilised for a few
days at most and the filters themselves require frequent sterilisation by fire, at
least weekly, so that the importance of the subject is enormously enhanced, from
the industrial standpoint.
The alkali which I propose to use practically for the treatment, of water, is
lime in proportions adequate to effect the precipitation of all the calcareous
bicarbonate which is generally held in solution in water and thus to form a lime
water. In this strongly alkaline medium all the pathogenic bacilli that water
can contain are destroyed and that even more suddenly and completely than by
corrosive sublimate. Even if typhoid or dysenteric dejections are mingled. with
the water the effect of the lime is successful in overcoming then in half-an-hour
whereas the 1 per cent. solution of corrosive sublimate or the 5 per cent. solution
of lime-chloride or chlorhydric acid only attain that result after a period of time
varying from 2 to.48 hours or even more; so that in fact a contaminated water
may with the utmost certainty be absolutely purified by the use of lime. Never-
theless though radically, purified in regard to the extermination of microbes the
water is not yet potable in this.state; and to render it so, nothing more is. requisite
than to extract and remove the caustic lime contained in it, which may easily be
effected by subjecting it to the action of a reagent capable of precipitating the
caustic lime and neutralising, the water after 'decantation or filtration.
reagent preferably thus employed is carbonic acid, which immediately forms
carbonate of lime, and being insoluble, this, is, precipitated and can then be separated
mechanically either by decantation or by filtration; the water thus obtained
Deither contains any microbes; nor excess of lime, that is to say, it is absolutely
pure..
The
The carbonic acid is supplied at pleasure in quantity sufficing to give a water
charged with an excess of carbonic acid as required, which acid excess is a
sterilising agent in itself and preserves the water in excellent condition.

page_text: It is evident that the mode of operation may be varied at will in accordance
with the principles above set forth without going beyond the scope of my
invention. Thus for example in separating the water from the lime-carbonate a
slight alkalinity may be left in the water, which is then mingled with other water
surcharged with carbonic acid whereby it may be totally neutralised and left with
a slight excess of carbonic acid.
In addition to the microbes which are with certainty killed by the process
above described the same result is attained with all animalcula larvæ frogs leeches
fish etc. that may be found in the water.
It is obvious that other reagents or chemical compounds capable of neutralising
lime water may be used instead of carbonic acid as e.g. the acid phosphate of
lime or tartaric acid which both give very good results, but the use of carbonic
acid is in all respects to be preferred, it is easily to be obtained and cheaply
by lime-kilns or lime-burning furnaces with the aid of a washer and a refrigerator,
and considered from this point of view alone this process may be regarded as an
extremely economical means of purifying calcarcous waters.
Dated this 20th day of July 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
Treatment of Potable Waters by Alkalinisation and subsequent
Neutralisation, with a view to their Sterilisation and Purifi-
cation.
I, HENRI JOSEPH NAPOLÉON BERGE of Brussels in the Kingdom of Belgium,
Professor of the University of Brussels, and Director of the Chemical Laboratory
of the Municipality, 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 :—
This invention has for its object to solve the great problem of the supply of
potable water to populous centres, i.e. of water perfectly sterilised and deprived of
all impurities by a process of great simplicity and of easy application, consisting
essentially in the alkalinisation and ultimate neutralisation of the water by an
alkaline agent.
This process constitutes an absolute guarantee of purity in respect of the typhoid
and cholera bacilli, whence may be deduced not only its infallible efficacy but also
its vast importance from the hygienic point of view, and notably in comparison
with the action of other means of purification hitherto employed, such for instance
as filtration &c. which is quite inadequate, inasmuch as most filters favour the
multiplication of micro-organisms, without also taking into account that even the
best methods of filtration, e.g. slow filtering through porcelain and at low
pressures, only give water which remains sterilised for a few days at most, and
the filters themselves require frequent sterilisation by fire, at least weekly, so that
the importance of the subject is enormously enhanced, from the industrial stand-
point.
In
The alkali which I propose to use practically for the treatment of water is lime
in proportions adequate to effect the precipitation of all the calcareous bicarbonate
which is generally held in solution in water, and thus to form a lime water.
this strongly alkaline medium all the pathogenic bacilli that water can contain are
destroyed, and that even more suddenly and completely than by corrosive sublimate.
Even if typhoid or dysenteric dejections are mingled with the water, the effect of
the lime is successful in overcoming them in half-an-hour, whereas a one per cent.

page_text: solution of corrosive sublimate or a five per cent. solution of lime chloride or
chlorhydric acid only attain that result after a period of time varying from two to
forty-eight hours or even more; so that in fact a contaminated water may with the
utmost certainty be absolutely purified by the use of lime. Nevertheless though
radically purified in regard to the extermination of microbes the water is not yet
potable in this state; and to render it so nothing more is requisite than to extract
and remove the caustic lime contained in it, which may easily be effected by sub-
jecting it to the action of a reagent capable of precipitating the caustic lime and
neutralising the water after decantation or filtration. The reagent preferably thus
employed is carbonic acid, which immediately forms carbonate of lime and being
insoluble this is precipitated and can then be separated mechanically, either by
decantation or by filtration; the water thus obtained neither contains any
microbes nor excess of lime, that is to say it is absolutely pure.
The carbonic acid is supplied at pleasure in quantity sufficing to give a water
charged with an excess of carbonic acid as required which acid excess is a
sterilising agent in itself and preserves the water in excellent condition.
It is evident that the mode of operation may be varied at will in accordance with
the principles above set forth without going beyond the scope of my invention.
Thus for example in separating the water from the lime-carbonate, a slight
alkalinity may be left in the water, which is then mingled with other water
surcharged with carbonic acid whereby it may be totally neutralised and left with
a slight excess of carbonic acid.
In addition to the microbes which are with certainty killed by the process above
described, the same result is attained with all animalcula, larvæ, frogs, leeches,
fish etc. that may be found in the water.
It is obvious that other reagents or chemical compounds capable of neutralising
the water after treatment with lime may be used instead of carbonic acid, as e.g.
the acid phosphate of lime or tartaric acid which both give very good results,
but the use of carbonic acid is in all respects to be preferred, it is easily to be
obtained and cheaply by lime-kilns or lime-burning furnaces with the aid of a
washer and a refrigerator, and considered from this point of view alone this process
may be regarded as an extremely economical means of purifying calcareous
waters.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is ;-
The process for the treatment of potable and other waters by the sterilising
action of an alkali such as lime and by the neutralisation of such alkaline waters
by the aid of reagents devoid of toxical action such as carbonic acid or the
like with a view to obtaining water pure and deprived of bacteriological taint
substantially as described.
Dated this 18th day of April 1895.
W. P. THOMPSON AND BOULT & WADE,
Agents for the Applicant.