CH605421A5 - Disinfecting water using hydrogen peroxide - Google Patents

Abstract

Bath-, drinking and industrial water is disinfected by (i) adding H2O2 and (ii) activating the H2O2 or catalysing its decompsn. H2O2 can be added before or after filtration. Catalysis usually takes place before filtering, e.g. with the opt. addn. of flocculants. The catalysts may be metals metal ions or metal cpds., pref. of Cu, Pd, Fe, ni, Co, Pb, Cd or Ag. Organic cpds. e.g. aldehydes may also be used.Good catalytic activity can be achieved by incorporating an electrolytic cell in cycle of water processing plant. The cell electrodes are pref. of Cu, graphite, Fe, Ni, Pt or Ag. H2O2 has high oxidising power and can reduce coli-bacteria count to 0.

Description

  

  
 



   The present invention relates to a method for disinfecting bathing, drinking and industrial water with hydrogen peroxide.



   The most important requirements placed on the treatment of bathing and drinking water are firstly an immediate disinfection and secondly the best possible depot effect. Furthermore, deodorization and fining of the treated water are aimed for.



   In industrial water treatment, a good bactericidal and algicidal effect without disturbing residues is required, such as B. in the food industry, with cooling water, ion exchangers, etc.



   The common disinfectants are oxidizing substances that have a germicidal effect on the cell membrane of the bacteria and also react with organic substances (dirt) in the water. The main disinfectants used to date for treating water include chlorine gas, chlorine dioxide, di-halo (chlorobromo-dimethylhydantoin) bromine, electrochlor, javel water (sodium hypochlorite) ozone and ozone with chlorine.



   All disinfectants used so far have advantages, as well as decisive disadvantages, such as: B. The smell of chlorine in the water and the air above it, pH rise in the water, chloramine formation in the pool water, high investment costs, poor depot effect, risk of accidents due to toxicity, difficult storage or poor oxidative power, etc.



   The present invention now proposes the use of hydrogen peroxide as a disinfectant with excellent oxidizing power and few disadvantages of the type described above for the treatment of bathing, drinking and industrial water.



   The method according to the invention for disinfecting bathing, drinking and industrial water with hydrogen peroxide is characterized in that hydrogen peroxide is added to the water and this is activated or its decomposition is catalyzed.



   The addition of hydrogen peroxide can take place before or after the filtration, depending on the type of preparation.



   The catalysis usually takes place upstream of the filter, e.g. B.



  at the same time with a possible addition of flocculants. As a catalyst, metals, metal ions or metal compounds of z. B. copper, palladium, iron, nickel, cobalt, lead, cadmium, silver, etc. can be used.



  But it can also organic substances such. B. aldehydes can be used.



   A very good catalytic effect can also be achieved by installing a power source in the water cycle of a water treatment plant. As electrode materials, substances such as B. copper, graphite, iron, nickel, platinum, silver, etc. in question.



   The following experiments show the good effect of hydrogen peroxide as a disinfectant in water treatment, where z. B. in bath water the value 0 is required for the amount of coliforms.



   Laboratory tests
These tests were carried out with a plastic basin with a volume of 40 l with Rhine water (taken from above the Mellikon power station).



   The water had a temperature of 200 ° C. and was circulated with feed pumps (circulation time 1 to 4 hours.



  and passed through a sand filter. The catalysis took place by means of a power cell in front of the sand filter. The current cell had copper electrodes, the voltage was 24 V and the current was 80 mA. The results are compiled in the following tables.



   Table I.
Experiments without 11202 without electricity cell Sampling H202 bacteria Date Time 100% coliforms remaining mg / l germs Germs in 100 ml in 100 ml Experiment 1:
11/4/75 0800 0 650 500
11/5/75 0800 0 850 280 Trial 2: 11/24/75 1600 0 2900 1500 11/25/75 0800 0 2400 1800
1600 0 1800 1700 11/26/75 0800 0 1450 1500
Table II
Experiment with 11202 without current cell Sampling H202 bacteria Date Time 100% coliforms remaining mg / l germs Germs in 100 ml in 100 ml Experiment 3:

   11/12/75 0930 0 2825 3150
1000 10 not determined not determined
1400 7 1275 1550 11/13/75 0800 0 740 830
Table III
Experiment with 11202 with current cell sampling H202 bacteria date time 100% coliforms remaining mg / l germs germs in 100 ml in 100 ml experiment 4: 5.11.75 0900 10 1110 15780
1000 4 2 1710 Trial 5:
12/8/75 1200 10 600 3440
1300 5 6 174
1400 6 3 63 Experiment 6: 17.12.75 0900 10 900 8100
1000 6 10 20
1400 4 0 6 Trial 7: 29.12.75 1100 10 500 4600
1300 5 0 120
1600 0 0 10 Try 8:
6.1.76 0800 10 875 1440
0900 10 0 280
Try in the Schauenberg swimming pool
A disinfection test was carried out in the Schauenberg swimming area, the infection and determination of the germ counts being carried out by the chemical laboratory of the City of Zurich.



   At the Schauenberg swimming pool, the water flows from the main pool (160 m3) into an intermediate tank (40 m3) and from here with a circulation pump via the pressure sand filter back into the main pool. The circulation is around 40 m3 per hour.



   The power cell was installed in front of the circulation pump while the hydrogen peroxide was added to the intermediate vessel.



   The details and data of the disinfection test are compiled in Table IV and the corresponding bacterial counts determined by the chemical laboratory of the City of Zurich in Table V.



   Table IV Date Time Basin H202 E. Cell Basin H202 from 1976 mg / l i. Operation Cu mg / l stopcock 12.2. 0800 - 0.025 0 Do 0830 - bacteria
1030 - 0 addition
1100 x
1200 2.7 x 6.3
1300 4.3 x 12.0
1400 7.1 x 12.2
1500 9.0 x 13.0
1600 10.5 x 13.0
1700 10.9 x 0.065 10.3
1800 10.3 10.0
2000 9.9
2200 9.0 13.2. 0800 3.9 0.08 3.4
0830 0.08 7.3
0900 4.8 11.5
0930 10.0
1000 6.3 9.5
1100 7.7 13.8
1200 8.8 12.2
1300 9.7 12.4
1400 9.9 12.4
1500 9.9 x 0.07 ¯ 11.5
1600 9.9 x 11.5
Table V 02.12.1976 Time Colif. Enterococci germs per 100 ml per 100 ml on a.

   Endogenous enterococcus agar Before the experiment 0800 0 0 After infection of the bath with coliform and enterococcal bacteria 1000 636 000 650 000 Disinfection 1100 532 000 464 000 System 1200 180000 295000 in operation 1300 95000 234000
1400 76 000 155 000
1500 51000 98000
1600 5800 42000
1800 230 11 000
2000 40 8 700
2200 10 110 02/13/1976 0800 0 0
1000 0 0
1200 0 0
1400 0 0
1600 0 0

 

Claims (1)

PATENT CLAIM Process for disinfecting bathing, drinking and industrial water with hydrogen peroxide, characterized in that hydrogen peroxide is added to the water and this is activated or its decomposition is catalyzed. SUBCLAIMS 1. The method according to claim, characterized in that one catalyzes by means of a current cell. 2. The method according to dependent claim 1, characterized in that one catalyzes by means of a current cell whose electrodes are made of copper, graphite, iron, nickel, platinum or silver. 3. The method according to claim, characterized in that one catalyzes by adding at least one substance which contains copper, palladium, iron, nickel, cobalt, lead, cadmium or silver. 4. The method according to claim, characterized in that one catalyzes by adding an aldehyde.