Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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In the removal of organic materials from liquids use iq
made most frequently of biochemical methods whose efficacy
depends upon the presence of organisms, present in the water
in nature, such as Rotifera, Vorticella sp., Parameceae,
Flagellum sp., Forticalle camparum, Protozoon sp. and the
presence of oxygen.
Generally contaminating material~ from the macro to the .
micro range, that is to say from 200 to 10 micronæ are re~
moved by sedimentation from the liquid before it is brought
into contact with an equiva-ent quantity o~ the above~
mentioned microorganisms and minute forms of life either in .-
a droppin~ method or in an activated sludge method with the
simultaneous supply of atmospheric oxygan.
Colloidal contaminating materials, colloidal su~pensions
; 15 and materials in the sAme order of size as ions are firstly
enzymatically converted in such biochemical stages and then
partly oxidized by metabolism of the organisms and are partly
: adsorbed by becoming attached to the organiqms.
A ~ecessary condition for obtaining a high efficiency
is the presence of co~ditions which are favourable for the
organisms, that is to say the right temperature, a pH-value
~ near neutral, the absence of poisons, such as bactericides,
: in3ecticides, heavy metals starting at a certain concentration
and the presence of phosphates and nitrogen compounds.
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Activated aludge installation~ with optimum degrees o~
efficiency are generally operated with e proportion of activated
sludge of 4 gram per liter.
~ he time the material remains in the raaction ~p~ces de-
5 pends upon the composition of the contaminating materials in ; ~ -
the liquid and amounts to between 1 hour to, in some cases, 48
hours in the case of particularly resistant sewagel ,
In the case of purely domestic sewage the dissolved
organic substances consist of carbohydrates, proteins and
sugars. ~hey make a rapid chemical degradation possibleO How-
ever, in the case o~ such cleaning processes after half an
hour~on average 250 ml of sludge ~g~ can be deposited,
as measured in an Imhoff funnel, per liter of sewage sludge
mixture and such sludge can only be dewatered with difficulty ; ;
even if owing to dangers to hygiene the sludge is placed in
so~called decomposing towers before dewatering.
Xighly concentrated sewage, as for example from slaughter~
houses, dairies, jam factories and premises for disposi~g of
animal bodies, can in accordance with experience to date only
be sufficlently purified in so~called prolonged activation
installations, in the case of which the charging rate per
I unit volume must partly be reduced to 0.3 kg BSB5 per square
meter of activated space per day.
~ In the case of sewage from paper and pulp industries ~;
3 25 similar difficulties occur9 in this respect more especially
glucosides, lignins, tannins and xylose resulting from the
break-down of wood make biochemical degradation more difficult.
Very often in the case of such sewage BSB5 discharge values
are obtained after the biochemical cleaning which are ver~
satisfactory but however the values for potassium permanganate
consumption and chemical oxygen requirement in accordance
with the dichromate method are often unacceptably higher than
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is the case with the measured biochemical oxygen require-
ment measured. The differences 8how in many cases that
with ~he biochemical processes only partial degradation occurs
and in the case of the BSB5 measurement the actual residual
load is not covered.
l~he cause for the differences in the last-mentioned
example are to be found substantially in the insufficient
enzymatic break-down of the contaminating materials in the
liquid before the actual biochemical oxidativn ~d adsorption.
Agricultrual sewage involves difficulties similar to
those occuring with known biochemical degradation processes.
In the case of sewage from mass pig farming it i5 known that
approximately 30% of the protein materials fed leave the
animals without digestion and it is only after complicated
splitting processes that they are in a condition fit for
oxidation by organisms in biological installations.
In normal domestic sewage numerou~ pathogenic microbes
are present which cannot be biochemically degraded and if at
all can only be removed by adsorption on biological sludge
from the sewage. It is possible to assume with certainty
that in every sample of normal domestic sewage at least
1,000,000 microbe~ are comprised per ml; in this respect
it is for the most part a question of Escherichia coli,
though however the proportion of facultatively pathogenic
microbes is very high so that sewage is to be considered
highly infectious.
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Efficient biochemical cleaning installations remove
98~ of the microbes by adsorption. On the basis of the
abovementioned example as a result in the discharge from a
30 well operated biological cleaning installation still 10,000
microbes in all remain per ml~ In the case of public waters
whi~h are permitted for human bathing and for drinking by
animals, not n~re than 10 microbes per ml should be present.
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Owing to the increasing quantities even of puri`fied
qewage in comparison with the quantit~ of water on the sur-
face of the ~arth which always re~ains the same, the danger
of infection by sewage is therefore increasing steadily.
~he method in accordance with the invention avoids the
above-mentioned disadvantages b~ the use as a preliminar~
stage of an electrochemical proces~9 the electro-M-method,
by means of which all colloidal materials and substantially ;
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all colloidal suspensions are removed from liquids. ~he
electro-M-method is assumed to be known.
The liquids comprise after the process substa~tially
only parts of colloidal suspensions and the dissolved organic
substances in addition to inorganic contaminating substances.
Since the electrochemlcal process brings about a sub-
stantial removal of all microbes from the liquids, the dis-
charged liquid is inocculated with lactic acid bacteria of
the Caucasian Kefir group.
In this respect it is a question of microbic organisms,
whick even in acidic condltion and up to pH-values of 10 re-
produce themselves by cell division very rapidly in the pre-
sence of atmospheric oxygen and after suitable conditioning ~ -
to conditions oxidize, more especiall~ sugar, glucose, pro-
teins and fats~ -
It has been found in tests that owing to the capabilit~
~` 25 of Kefir organisms to degrade proteins a certain cannibalism -`~
results which has a favourable ef~ect on the pathogenic
microbes also existing as is known on a protein basis in the
liquids.
~he consequence of the procedure in which firstl~ by
means of electrochemical processes or chemical processes,
which are al50 possible but owing to the large amounts of
sludge involved and of other consequences which are disadvan-
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tageous for protectin~ water, such as salting out, increasing
the sulfate load etc., the sewage or other liquids is sub-
stantially freed of all contaminating material~ with the
exception of colloidal suspensions and dissolved materials
and is then exposed to the action of Kefir microorganisms, i~
that as compared with prior art biochemical processes a de-
cidedly lower quantity of sludge is obtained as excess sludge.
It has been found in several cases that it is only after
the additional floculation with organic precipitating ma-
terials that small quantities of sludge can be removed fromthe purified water.
The Kefir microorganisms used in the method of the in-
vention are cultured from Kefir mould with the addition of
substantially defatted milk at room temperature, the milk
serving as a nutrient material for the organisms. As a result
the nutrient solution is decomposed and a spherical coherent
culture remains. ~he culture is sieved out and washed with
drinking water.
After the first washing operation preferably a part of
20 the culture remaining is added to ten times as much water~ -
then dispersed and the suspension is then centrifuged. ~he
centrifugate is used as a material for inocculating the liquid
to ba cleaned, to which it i9 added.
It i9 also possible to add the culture after the first
25 washing operation directly to the liquid to be cleaned
It has been found in accordance with experience that in
the case of the use of the centrifugate as inocculating
material the inocculated water should be ~upplied to a drip
body-like column in which however departing ~-rom d~}p bo~d~
fillin~ material filling bodies with a cylindrical form are
used con~istin~ of stainles~ antimagnetic steel fabric with
~ mesh width of less than 300 microns. This leads to a ~ubstan-
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tial increase in the surface in the column as compared with
normal drip body material and per gram of the filling body
material for the lawn of microorganisms a 3urface of 2 square
meters is made available.
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' 5 ~he liquid inocculated with the microorganisms i~ ~x~
several times through the column. As is the case wit~ a drip
body the entering water is pas~ed by a rotary sprinkle onto
the column.
Examples for the reduction of the chemical oxygen :require-
ment in accordance with the dichromate method~
(1) Precleaned sewa~e from a toilet paper factor~
after electrochemical treatment with the electro-M-method
CSB 40 mg/l,
1.1 after addition of 2 ml of microor~anism oentrifugate
per liter and 2 hour~ of treatment time in the drip
' column CSB 10 mg/l.
(2) Precleaned domestic sewa~e ;
after electrochemical treatment with the electro-M-method
CSB 184 mg/l,
2.1 after addition of 5 ml of microorganism centrifugate
per liter and 4 hours of treatment time in the drip
column CSB 28 mg/l. ,
' (3) Precleaned textile sewa~e~water_from disper~ion d~in~
3 vats after electrochemical treatment with the electro-M-
method CSB 296 mg/l,
3.1 after addition of 10 ml of microorgani~m centrifu-
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~, gate per liter and 2 hour~ of treatment time in the
drip column CSB 194 mg/l,
3.2 after a further 2 hours
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CSB 82 mg/l,
3.3 after a further 2 hour3
CSB 41 mg/l.
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: (4) ~he water in accordance with 3.2 within 2 hours
50 % of precleaned communal water was added,
entry C~B 225 mg/1,
4.1 after 2 hours of treatment time in the drip column
CSB 62 mg/l,
. 4.2 after a further 2 hours
; CSB 34 mg/l.
(5) ~he water in accordance with 4.2 within 1 hour 50 %
precleaned textile sewage was added.
~0 entry CSB 3~0 m~/l,
5.1 after 2 hours of treatment time in the drip column
CSB 194 mg/l,
after 4 hours
CSB 152 mg/l,
after 8 hours
CSB 48 mg/l. ~ :
~he BSB5 of this sample was 20 mg/l.
(6) Precleaned sewage from_a skin ~lue factor~
. after electrochemical treatment with the electro-M-method
. 20 CSB 883 mg/l,`
6.1 after addition of 20 ml of microorganism cen-trifu-
: gate per liter and 2 hours of treatment time in the
; prepared dripping column CSB 182 mg/l,
after 6 hours of treatment time in the drip column
` C~B 52 mg/l.
:~ ~urther~ore, the inocculation of classical biochemical :
~, activated sludge installations with the centrifugate of the :
:l Kefir microorganisms or the washed-out mould cultures show
.: substantial improvements in the efficiency on the basis of the treatment time of the water in the biological stage.
~ However no substantial change in the excess sludge quan
.~:i tities could be detected, something which could be clearly
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found in the case of addition of the inocculating composition
in a pure form.
Visible residual turbidity was decreased b~ the addition
of Kefir microorganisms to the water and the odour in contrast
5 to the discharge from known biological stages is no longer ~ `
m~uldy or earth-like and instead i6 fresh or neutral. ~ -
~he microorganisms can be considered to be extraordinarily
stable, as a few test examples will show
Example 1: The culture taken from the milk nutrient solution
was stored in a Petri dish for 8 days in a ~terile
cupboard and then washed out and centrifuged. In
the centrifugate numarous Kefir microorganisms were
comprised which after the addition of nutrient so-
lutions reproduced very rapidly.
Example 2: ~he centrifugate obtained in example 1 was stored
for 26 days in a bottle with a ground glass stopper
with 50 % ullage at a temperature of +6C in a re-
frigerator and then the centrifugate was used again
for inocculating sewage. In the centrifugate the ~-
microorganisms were present in great numbers. Dead
cells could not be detected.
~xample 3: A drip column inocculated with the centrifugate in
; accordance with example 2 had after 8 weeks of test
procedure such an extensive culture that further
inocculation was no longer necessary even in the ~;
case of cleaning tests with the most various diffe-
rent forms of sewage.
~ii The aerobic microorganisms passing with the sewage
into the column, which are used in the case of
normal biochemical cleaning, were not impaired by
the Kefir microorganisms.
However, it could be found in this case as well that the
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excess sludge quantity was substantially reduced so tha t it
can be suppo~ed that the main cleanin~; effect can be attributed
to the Kefir microorganisms.
In the case of the use of the drip columrL it was pre
5 ferred to work with a body whose height i~3 20 time~ its dia- :
meter, The overall volume was reduced by 50 % by the metal
filling bodibs.
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