Products
- Titanium Anode
- Sodium Hypochlorite Generator
- Cathodic Protection
- Electrodeposition of Metals
- Sewage Treatment
- Electroplating
- Hydrogen Generator
- Desalination of Sea Water
- Disinfection of Swimming Pool
- Etching Solution to Recover Copper
- Titanium Bicycle Parts
- Titanium Handlebar
- Titanium Frame
- Titanium Fork
- Titanium Stem
- Titanium Seatpost
- Titanium Pedal Spindle
Study on Disinfection of Drinking Water by Preparing Sodium Hypochlorite on Site
For the disinfection effect of sodium
hypochlorite generator, chlorine dioxide generator and finished product sodium
hypochlorite after disinfection
The generation of disinfection by-products
was studied, and the characteristic test of the finished sodium hypochlorite
solution was carried out.
Safety management and operating costs of a
disinfection method. The results showed that the disinfection and sterilization
effects of the three disinfection methods were not significant.
However, the types of disinfection
by-products produced by chlorine dioxide and sodium hypochlorite are different,
and the disinfection by-products of sodium hypochlorite are different.
Most of them are trihalomethanes and
haloacetic acids, and chlorine dioxide disinfection mainly produces chlorate
and chlorite. Sodium hypochlorite
There was no significant difference in the
level of disinfection byproducts between the sodium hypochlorite solution
prepared by the bioreactor and the finished sodium hypochlorite solution. to
make
The content of bromate in the sodium
hypochlorite solution was significantly higher than that of the solution
prepared by the sodium hypochlorite generator, and increased with the storage
time.
With the increase of , the finished sodium
hypochlorite solution has the phenomenon that the available chlorine decays and
the chlorate content increases.
At present, the disinfection of tap water
generally adopts liquid chlorine,
Disinfection methods such as chlorine oxide
and sodium hypochlorite [1]. liquid chlorine disinfection
The cost is relatively low, and it is the
most widely used in water plant disinfection, but
Liquid chlorine and chlorination rooms are
a major source of danger in cities. With the country's
The requirements for the management of
dangerous goods are becoming more and more stringent, and some areas have
The article stipulates that the use of
liquid chlorine for disinfection is not allowed. Chlorine dioxide is a
broad-spectrum high-efficiency disinfectant.
In comparison, the killing effect on
pathogenic microorganisms in water is good, and the effect
Fast [2]. Chlorine dioxide generators
generally use hydrochloric acid and chlorine
Sodium is the raw material, both of which
belong to the control of hazardous chemicals
range, especially hydrochloric acid, is
highly corrosive in transportation and use,
There are safety hazards; and pungent in
daily production configurations
odor, and the production operating
environment is poor.
Sodium hypochlorite not only has a strong
bactericidal effect, but also
And it has the characteristics of easy
decomposition, no residue, less toxic to human body, etc.
It is an important development direction of
drinking water disinfection in the future [3]. out
For hazardous chemicals management, safety,
production operating environment
Considering that more and more water plants
choose to use sodium hypochlorite to eliminate
poison. There are two ways to obtain sodium
hypochlorite, one is to chlor-alkali
The factory buys the finished sodium
hypochlorite solution, and the second is to use water, electricity,
Salt is electrolyzed to safely produce
hypochlorite on-site in water plants
Sodium solution. Chlorine dioxide generator
and sodium hypochlorite generator
Toxic effect comparison.
Table 1 Comparison of raw water
characteristic indicators
Item
June
July
Thermotolerant
coliforms(pc/L)
1600
540
Arsenic(mg/L)
0.0032
0.0053
Iron(mg/L)
1.00
0.67
Copper(mg/L)
0.0019
0.0022
Fluoride(mg/L)
0.51
0.61
Nitrate(mg/L)
0.99
1.08
Chloride(mg/L)
50
56
Sulfate(mg/L)
53
56
Permanganate
Index(mg/L)
3.00
3.20
Ammonia
Nitrogen(mg/L)
0.07
0.07
Chenical
Oxygen Demand(mg/L)
12
9
Total
Phosphorus(mg/L)
0.101
0.124
Total
Nitrogen(mg/L)
1.48
1.38
Petroleum(mg/L)
0.03
0.029
Dissolved
Oxygen(mg/L)
6.8
4.74
Table
2 Comparison of two disinfection methods of chlorine dioxide and sodium
hypochlorite generators
Item
Chlorine
Dioxode Generator
Sodium
Hypochlorite generator
Factory
water
I
clean water
Ⅱ clean water
Factory
water
Total
Coliform
ND
ND
ND
ND
Thermotolerant
coliforms(pc/L)
ND
ND
ND
ND
Escherichia
coli
ND
ND
ND
ND
Total
bacterial count CFU/ML
ND
4
2
ND
Chloroform（mg/L）
<0.001
0.0027
0.0088
0.0061
Dichloromonocromomethane(mg/L)
0.0016
0.0055
0.014
0.0091
Dichlorodibromomethane(mg/L)
0.0032
0.0068
0.014
0.0092
Tribromomethane(mg/L)
<0.0025
<0.0025
0.0039
0.0043
Total
trihalomethanes
0.09
0.22
0.56
0.37
Trichloroacetic
acid(mg/L)
<0.001
0.0033
0.0039
0.0043
Dichloroacetic
acid(mg/L)
<0.0004
0.0029
0.0042
0.0039
Chlorite(mg/L)
0.21
<0.01
<0.01
<0.01
Chlorate(mg/L)
0.64
0.046
0.055
0.06
Disinfectant
residue(mg/L)
0.13(chlorine
dioxide)
0.54(Free
residual chlorine)
0.80(Free
residual chlorine)
0.56(Free
residual chlorine)
Table 3 Small test experiment on the
disinfection effect of sodium hypochlorite generator and finished sodium
hypochlorite
Item
Finished
sodium hypochlorite
Sodium
hypochlorite generator preparation solution
Initial
effective chlorine concentration(mg/L)
1.25
1.88
2.5
1.25
1.88
2.5
Total
bacterial count(CFU/ML)
ND
ND
ND
ND
ND
ND
Chloroform（mg/L）
0.0045
0.0068
0.006
0.0046
0.0073
0.0067
Dichloromonocromomethane(mg/L)
0.0053
0.0066
0.0064
0.0055
0.0076
0.0072
Dichlorodibromomethane(mg/L)
0.0053
0.0057
0.0052
0.0052
0.0062
0.0055
Tribromomethane(mg/L)
<0.0025
<0.0025
<0.0025
<0.0025
<0.0025
<0.0025
Total
trihalomethanes
0.23
0.29
0.27
0.23
0.32
0.3
Trichloroacetal
0.003
0.0051
0.0056
0.0034
0.0041
0.0062
Trichloroacetic
acid(mg/L)
0.0036
0.0052
0.0056
0.0036
0.0055
0.0061
Dichloroacetic
acid(mg/L)
0.0021
0.0041
0.005
0.0026
0.0057
0.0069
Chlorite(mg/L)
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01
Chlorate(mg/L)
0.053
0.077
0.103
0.075
0.109
0.140
Terminal
residual chlorine(mg/L)
0.51
0.89
1.27
0.57
0.95
1.40
Table 4 Comparison of operating costs of
chlorine dioxide, finished sodium hypochlorite and on-site preparation of
sodium hypochlorite
Disinfection
Method
Raw
Material
Running
cost(cny.kg available chlorine)
Chlorine
Dioxide
Sodium
chlorate, hydrochloric acid
7
Finished
sodium hypochlorite
Purchased
from chlor alkali plant
8
Site
preparation of sodium hypochlorite
Salt
3.7-5
There is no significant difference in
disinfection and sterilization effect between sodium hypochlorite generator and
chlorine dioxide generator, but the types of disinfection by-products are
different. Sodium hypochlorite disinfection will generate trihalomethanes and
haloacetic acid disinfection by-products, chlorine dioxide disinfection
by-products are mainly
are chlorate and chlorite. There was no
significant difference between the sodium hypochlorite solution prepared by the
sodium hypochlorite generator and the finished sodium hypochlorite solution in
the disinfection and sterilization effect and the level of disinfection
by-products. The bromate content in the finished sodium hypochlorite solution
is significantly higher than that of the sodium hypochlorite solution prepared
by the sodium hypochlorite generator. And with the increase of storage time,
the finished sodium hypochlorite solution exists
Phenomenon of available chlorine decay and
chlorate content increase. 1% sodium hypochlorite prepared on-site in a sodium
hypochlorite generator
The solution is a safe product, is
non-toxic to the environment, has good safety, and significantly reduces
operating costs, which is convenient for production operations.
