Case study: № 1.
When the sanitary survey treatment plant aeration "Boz-su" established
that the waste water of the city of Tashkent in the amount of 80,000 cubic
meters day passes cleaning on these plants: grille, sand traps, circular tanks,
aeration tanks, secondary circular tanks. Wastewater disinfection with
chlorine is carried out. The contact time is 30 minutes, if the index after
chlorination effluent 650 - 950, residual chlorine of 1.6 - 1.7 mg / l.
Rate purification scheme, the conditions and the effectiveness of
chlorination.
Solutions.
The purification scheme for the purification WWTP "Boz-su" correctly.
Terms and effectiveness of chlorination meets the hygienic requirements as
for 0056-96 SanPin contact time must be at least 30 minutes, if the index is not
more than 1000 chlorine residual of at least 1.5 mg / lСитуационная задача:
№ 2.
When the sanitary survey WWTP "Boz-su" set that sewage of the city of
Tashkent in the amount of 150,000 cubic meters day passes cleaning on these
plants: sand traps, circular tanks, aeration tanks. Wastewater disinfection with
chlorine is carried out. The contact time is 30 minutes, if the index after
chlorination -1000 700 sewage, residual chlorine of 1.5 mg / l.
Rate purification scheme, the conditions and the effectiveness of chlorination.
Solutions.
The purification scheme for the purification WWTP "Boz-su" wrong, because
according to KMK "Sewerage. Internal and external networks "should be grille and
secondary sedimentation tanks. Terms and effectiveness of chlorination meet
hygienic requirements, as for 0056-96 SanPin contact time must be at least 30
minutes, if the index is not more than 1000 chlorine residual of at least 1.5 mg / l
Case study number 3.
When the sanitary survey WWTP "Boz-su" set that sewage of the city of Tashkent
in the amount of 150 cubic meters day passes cleaning on these plants: sand trap
grille, circular tanks, aeration tanks secondary sedimentation tanks. Wastewater
disinfection with chlorine is carried out. The contact time is 25 minutes, if the
index wastewater after chlorination 1600 - 1900, residual chlorine of 1.2 - 1.4 mg /
l.
Rate purification scheme, the conditions and the effectiveness of chlorination.
Solutions.
The purification scheme for WWTP "Boz-su" wrong, because according to
KMK "Sewerage. Internal and external networks' money had to be aeration
tanks and secondary sedimentation tanks. Terms and effectiveness of
chlorination does not meet hygienic requirements, as for 0056-96 SanPin
contact time must be at least 30 minutes, if the index is not more than 1000
chlorine residual of at least 1.5 mg / l
Case study number 4
Assess the effectiveness of wastewater treatment aeration station "Boz-su"
according to this protocol №35.Spusk wastewater is carried out in the river
Boz-Su within the city limits.
Protocol №35.
Studies wastewater purification steps.
Location of sampling -ochistnye facilities.
Time-sampling 25.12.2008g.
indicators analysis
waste water
Incoming
After
circular
tanks
BOD, mg.02 / l
125.0
110.0
after
aeration
after
chlorination
12.0
10.0
11.0
37.0
99.0
99.0
Relative stability,%
55.0
55.0
50.0
50.0
Chlorides, mg / l
18.2
18.0
10.2
9.8
Ammon nitrogen, mg / l
0.0
0.0
0.1
0.14
Nitrite Nitrogen, mg / l
0.0
0.0
9.6
9.0
nitrate nitrogen
-------
--------
--------
1.5
Solutions
In assessing the biological treatment should first clarify the analysis of
waste water availability indicators reflecting 1 (BOD stability) and 2
(ammonia nitrogen, nitrate nitrogen) phase oxidation of organic substances.
To assess the technical efficiency of biological treatment is necessary to
focus on the performance analysis of wastewater BOD aqueous stability of the
compounds of group nitrogen (ammonia nitrogen, nitrite nitrogen, nitrate
nitrogen). Method of determining the technical efficiency izlazhena above.
Results: The technical efficiency for BOD. Is 96%, which meets the
requirements of CMC Sewerage.
From the analysis it follows that the process of oxidation of organic
substances is evidenced:
1 snizheniyayae ammonia nitrogen concentration from 18 to 10.2 mg / l
2-appearance of nitrite and nitrate nitrogen (0.1 and 9.6 mg / l)
Assessing the relative stability of the wastewater should be aware that the
biological treatment is effective in terms of the relative stability of at least
80% in the above analysis .Poskolku wastewater stability after biological
treatment is 99% it can be otsenina positive.
Case study number 5
Assess the effectiveness of wastewater treatment aeration station "Boz-su"
according to this protocol №215.Spusk wastewater is carried out in the river BozSu within the city limits.
Protocol №215.
Studies wastewater purification steps.
Location of sampling -ochistnye facilities.
Time-sampling 20.10.2008g.
indicators analysis
Waste water
Incomin After
after
g
circular
aeration
tanks
Temperatura.S
22.5
22
19.5
after
chlorination
20
transparency
1.5
9.5
12.0
19.0
Precipitate volume
2.1
1.1
0.9
0.2
suspended solid matterin mg / l
115.0
50.0
95.0
20.0
Total mikrob.
380000
92000
38000
3000
if the index
2380000
238000
238000
800
Residual chlorine mg / l
--------
-------
-------
1.5
Solutions
To evaluate the effectiveness of the mechanical cleaning technology primarily
from analysis should identify indicators wastewater precipitate volume defined in
further transparency (%) reduction in the concentration of suspended solids (x1)
precipitate (x2) after the mechanical treatment compared to the incoming. Taking
as 100% the amount of suspended solids or sludge volume in the incoming waste
water find% suspended solids remaining in mg l and sludge volume.
50 x 100 1.0 x 100
X 1 = ---------------------- = 43.4%, X2 = -------------------- ------- = 43.4%
115 2 3
It follows that the technical efficiency of mechanical treatment is 43.4%. The analysis shows that,
along with a decrease in the weighted substances increases the transparency of
wastewater 1.5do 9.5sm.
Assessing technical efficiency mechanical treatment should focus on the KVM
Sewerage which provides for effectiveness delay the weighted substances in
lagoons at 40 to 45%.
To evaluate the effectiveness of disinfection should be in addition to
determining the number of index% reduction rely on surface water from sewage
pollution SanPin 0056-96 .Otsutstvie content in the water of pathogens achieved
by disinfection of biologically treated wastewater to the number of index at most
1000pri residual chlorine to less 1.5 mg / l.
Thus wastewater treatment both in mechanical stage shows low technical
efficiency, but the effectiveness of decontamination meets the hygienic
requirements.
Case studies: № 6
Assess the effectiveness of wastewater treatment aeration station "Bozsu" according to this protocol №25.Spusk wastewater is carried out in the river
Boz-Su within the city limits.
Protocol №25.
Studies wastewater purification steps.
Location of sampling -ochistnye facilities.
Time sampling-15.10.2008.
indicators analysis
Waste water
Incomin After
after
after
g
circular
aeration
chlorination
tanks
Temperatura.S
24.5
22
19.5
22
transparency .See
3.5
8.5
15.0
19.0
Precipitate volume
2.7
1.9
1.0
0.5
suspended solid matterin mg / l
125.0
85.0
90.0
18.0
Total mikrob.chislo
375000
94000
35000
3000
if the index
2550000
245000
245000
850
Residual chlorine mg / l
--------
-------
-------
1.4
Case studies number 7
Assess the effectiveness of wastewater treatment aeration station "Boz-su"
according to this protocol №15.Spusk wastewater is carried out in the river Boz-Su
within the city limits.
Protocol №15.
Studies wastewater purification steps.
Location of sampling -ochistnye facilities.
Time-sampling 05.10.2008g.
indicators analysis
Temperatura.S
22.5
Waste water
After
after
circular
aeration
tanks
21.2
20.7
Transparency. see
3.3
10.0
15.0
18.5
Precipitate volume
2.9
1.5
0.75
0.32
suspended solid matterin mg / l
118.0
57.7
96.5
17.9
Total mikrob.chislo
378000
92600
35000
3700
if the index
2415000
275000
23500
950
Residual chlorine mg / l
--------
-------
-------
1.3
Incomin
g
after
chlorination
19.8
Case studies number 8
Assess the effectiveness of wastewater treatment aeration station "Boz-su"
according to this protocol №17.Spusk wastewater is carried out in the river Boz-Su
within the city limits.
Protocol №17.
Studies wastewater purification steps.
Location of sampling -ochistnye facilities.
Time-sampling 02.10.2008g.
indicators analysis
Waste water
incoming After
circular after
after
tanks
aeration
chlorination
Temperatura.S
23.5
21.5
18.7
19.6
Transparency. see
2.0
8.5
13.2
18.4
BOD
125.0
110.0
12.0
10.2
relative stability
15.0
37.0
90.0
95.0
chlorides
58.0
57.0
55.0
52.0
if the index
2390000
239000
239000
760
Residual chlorine mg / l
--------
-------
-------
1.3
Case studies number 9
When san. Survey treatment plant orders. doctors established that the fault of
the chief engineer of the sewage treatment plant control treatment plant is carried
out once a week. These laboratory analysis showed that the effluent quality to
allow epidemiological indicators consider water sbrasyvaemy open water
epidemiological safety, but the chemical content exceeds health standards as
Benzene content 5.2 mg / liter. Lead of 2.5 mg / l earlier by employees of the
treatment plant violations were noted. Give solutions.
Case studies number 10
When san. Survey treatment plant orders. doctors established that the fault of
the chief engineer of the WWTP control of chlorination of water is carried out
once a week. These laboratory analysis showed that the effluent quality to allow
epidemiological indicators consider water discharged into open water
epidemiological safety. Previously by employees WWTP violations were noted.
Give a solution.