Case study.
Task №1.
In connection with the expansion of construction in Gulistan and placing engineering plant
in the river Sirdar scheduled discharge of industrial effluents containing copper, zinc and
cyanide. Sirdar river according to laboratory analyzes urban CSSES specific contaminants
does not contain a paragraph near water (settlements Dustabod) 12 km below the effluent
discharge is used for drinking purposes.
The design flow of the river "A» Q = 60,0 m3 / sec. Mixing ratio in the calculation to
determine the design and alignment is a = 0.4. Flow of wastewater q = 0,2 kub.m.sek. The
concentration of impurities in the effluent cyanide - 55.0 mg / l of copper - 18.0 mg / l zinc
120.0 mg / l.
Determine the conditions under which the manufacturing plant and wastewater can be
discharged into the river Sirdar according SanPin 0056 - '96.
Solution of the problem №1
The concentration of pollutants in the wastewater which can be reset in a reservoir in
accordance with the requirements of "Rules of protection of surface waters from sewage
pollution" (SanPin 0056 - 96) is given by:
Qxa
For a = --------- (the PDC - By the river) to the MPC +
q
1. Possible summation of action for discharge to the pond several substances must first
determine each concentration of these substances in the water can be considered valid.
To do this, we write from San PiN 0015 - 96 Appendix List of MPC in the pond for the
intended, reset substances and limiting parameters for which they have been approved:
names pollution
approved MPC
limiting rate
cyanides
0,1
copper
zinc
1,0
1,0
sanitary
toksichesky
organoleptic
Obschesanit
MPC with
summation
- 0,1
1,0
1,0
the
Because All three substances of different character actions (have different limiting value),
the summation of action does not have, and because the concentration of each of them in
the water will be safe at approved (full)
2. Determine the allowable reset contamination concentration in wastewater:
0.4 x 60
a) to Art. Cyanogen. ---------------- X = (0.1 - 0) + 12 = 0.1 mg / l
0.2
0.4 x 60
b) to Art. copper. ---------------- X = (1.0 - 0) = 121 + 1.0 mg / l
0.2
0.4 x 60
c) to Art. Cyanogen. ---------------- X = (1.0 - 0) = 121 + 1.0 mg / l
0.2
The calculations show that allowed the discharge into the reservoir concentration of
copper and zinc in the effluent more than scheduled reset.
Therefore, it is necessary effluent from cyanide 78% (55 mg / l - 12 mg / l) = 43 mg / l,
which is 55 mg / L = 78%
Conclusion. According to the calculations discharge of effluent from mashinostroi telnogo plant in Sirdar river is possible only if the conditions of their treatment of cyanide
to the residual concentration of not more than 12.0 mg / l ie 76%.
Problem №2
In the town of Almalyk projected construction of non-ferrous metallurgy.
Determine the conditions under which the waste water can be discharged into the river
Almalyk if, according to the organization received from projecting the number of sewage
0.04 kub.m.sek.
Concentrations of contaminants therein cyanide = 50 mg / l, thiocyanates = 120 mg / l =
Lead 24.0 mg / l Zn = 300 mg / l.
The nearest water point is 16 km below the effluent discharge yavlyaetsyaposelki "Hur",
whose population enjoys vodoprodnoy water from the river "Almalyk".
The design flow of the river "Almalyk" = 12 kub.m.sek. and the mixing ratio runoff from
river water in the calculated alignment = 0.8. River "Almalyk" according to the sanitary
surveillance of specific contaminants does not.
Decision task №2
The calculation of the concentration of pollutants in the wastewater, which can be reset in
the pond without violating the requirements of SanPiN 0056-96 conducted by the formula:
Qxa
For a = --------- (the PDC - By the river) to the MPC +
q
However, before substitute values into the formula, "the PDC" should be carried out, what
the concentration of each of the 4 substances discharged in the pond will be really valid,
ie, harmless. After all, in the pond will be a complex matter (4-substances), and approved
by the MPC for each set of isolated action.
Write down the approved (full) MPC for each substance in the water and limiting their
performance.
names pollution
approved MPC
cyanides
0,1
limiting rate
MPC with
summation
- 0,1/3 = 0,03
the
sanitary
toksichesky
thiocyanates
0,2
sanitary
- 0,2/3 = 0,06
toksichesky
lead
0,03
sanitary
- 0,03/3 = 0,01
toksichesky
zinc
1,0
Obschesanit
1,0
Thus, in the calculation formula on the basis of SanPin substitute one third of the
maximum permissible concentration of toxic substances approved:
By st.tsian. = 0.8 x 12.0 / 0.04 x (0.03 - 0) + 0.03 = 7.27
By Art. thiocyanates = 0,8h12 / 0.04 (0.06 - 0) + 0.06 = 14.46
FTC. Lead = 0,8h12 / 0.04 (0.01 - 0) + 0.01 = 2.41
To calculate the concentration of zinc in the effluent, which can be reset in a reservoir,
supplying a complete MAC approved because substances that affect the sanitary
conditions of the reservoir is only one:
By st.tsink = 0,8h12 / 0.04 (1.0 - 0) + 1.0 = 241.0
Conclusion: According to the results of the calculations designed plant effluents can be
discharged into the river "Almalyk" only if they are clean from cyanide at least = 85.5%
from 88.0% thiocyanate = 90% of lead and zinc by 20% ie until the residual concentration
in the effluent not exceeding 7 Cyanide mg / l, thiocyanates = 12.0 mg / L lead = 10 mg / l
zinc and 240 mg / l
Case studies:
Problem №1
on sanitary inspection presented a project to build a city of communication in "A".
According to the project in the municipal sewage system appear the economic bit of water
pollution and industrial waste water after pre-treatment at local facilities. The project
provided a complete biological treatment of wastewater disinfection. Scheduled discharge
of sewage into the creek, a tributary of the river used downstream for mass use.
Names! concentration in mg.l. ! limitative
! for you! Calc. ext. ! In water vodaema! MPC! indicator
harmfulness
MIC
15
17.15
6.0
Suspended solids
15
15.54
7.0
Nickel
0.08
1.54
0.068
0.1
toxic.
Silver
0.09
1.54
0.06
0.1
toxic.
Copper
0.04
6.45
0.02
1.0
Give your opinion on this situation.
1-for-3
11th to 6
Authority.
Problem №2
The city was built ore-dressing plant, waste water of 100 m3 / day. will be allocated in a
citywide sewer system cleaning and tuck in conjunction with the host-bit art. reservoirs on
the next page. plants: grille, sand trap, mountains. sump, contact tank, wastewater oredressing plant have lyrics. composition:
1.Color - Black
2. Transparency, see - 0
3. The odor scores - 0
4. weighi. substances mg / l - 60.000
5. precipitate% of the volume of waste liquid after 30 minutes - 70
6. The dry residue in mg / l - 3000
7. 20 BOD, mg / l -6.0
Rate decision on the organization of wastewater ore-dressing plant
Problem №1
The city "Kakand" on existing chemical plant is scheduled to host the new production in
the effluent that will contain phenol and formaldehyde.
Give opinion on the possibility of construction of the production with the discharge of
effluent into the river "Sirdar" if:
- The amount of waste generated q-0.8m / s
- The concentration of pollution they Sstfenola - 40 mg / l;
- Sstformaldegida - 60 mg / l;
- The minimum design flow of the river "Sirdar» - Q - 70m3 / s
Problem №2
Assess the effectiveness of wastewater treatment aeration station according to
given protocol (№ 100), water discharge is carried out in the Amu Darya River within the
city limits.
Minutes №100
Studies wastewater purification steps.
Place of sampling - wastewater treatment plants.
Take Time proby- 29.09.2009
Index analysis
After pleased.
Wastewater do.
After After chlorine
Ostoy Cove aeration
1.Temperatura C
22.5
22
19.6
20
2.Prozrachnost, cm
2.0
9.0
13.0
19.0
3.Vivesch.veschestaya mg.l
110.0
55.0
92.0
16.0
7.6
7.7
7.7
4.rN.
7.6
5.BPK full OL mg
125.0
110.0
12.0
10.0
55.0
50.0
50.0
6.Hloridy
55.0
7.Azot ammiyak mg.l.
18.2
18.0
8.Azot nitrite mg.l.
0
0
0.1
0.14
9.Azot nitrates mg.l.
0
0
9.6
9.0
10.Obsh.mikr.chislo
380000
92000
11.Koli code
2380000
12.Ostat. chlorine mg.l
.-
238000
-
10.2
9.8
38000
3000
238000
800
-
1.5
Case study.
Case study: At the River "Karasu" of wastewater, the city sewer "Tashkent" and industrial
waste water located in the chemical industry. Results of the study of water in the river,
"Karasu" in the alignment of the water intake of "Tashkent" (above the city) and the
nearest water point is located 8 km. descent below the drains, the "T" shown in the table.
Population on. "Pakhtakor" for drinking river water uses..
Key indicators of Concentration
MPC in the water Limitiruyuschii
pollution
reservoir
mg.l.
hazard rate
Water intake. , the
"T" DP
The smell in points 2
BOD
3
2
1.5 18.0
1 кат – 3, 2 – кат
6
aniline
0
0,05
0,1
sanitary
-
toksichesky
cyclohexanone
0
0,2
0,2
sanitary
-
toksichesky
formaldehyde
0,1
0,4
0,5
sanitary
-
toksichesky
caprolactam
0
2,05
1,0
Obschesanit
1. Assess the levels of pollution in the water "Karasu" in the water intake of
"Tashkent" and the village "Pakhtakor" toxic substances, organic change the properties of
water, total organic pollution (BOD).
2. give an opinion on the appropriate conditions of descent of sewage in the river.
"Karasu" requirements of the rules for the protection of surface waters from sewage
pollution.
Solution of the problem:
Based on these laboratory study found:
the smell of the normal range, BOD in water intake, the "Tashkent" is satisfied, we
point "Pakhtakor" BOD exceeds 3 times, chemical substances within the normal aniline,
cyclohexane, normal, normal, formaldehyde, caprolactam from the intake of "t" is not
detected, and the population "Pakhtakor" exceeds MPC by 2 times. Based on the highest
level of guest are invited to enter the emerging waste pond OZHMST from organic
substances and residues from cleaning to caprolactam to limit the MPC.
Problem №2
In Navoi based on an existing chemical plant is planned to place the new production,
which is contained in the effluent aniline. Give opinion on the possibility and conditions of
aniline containing wastewater discharge into the river Zarafshan, if:
Number of aniline containing effluent kub.m.sek = 0.2. Aniline concentration in the
effluent Fst = 10.0 mg / l, the estimated consumption of the Zarafshan River in the
alignment of the nearest water point (with T 10 km downstream from the discharge point)
25.0 kub.m.sut and specific pollution in the river "M" in the village of G in real time, there
is only (Cr) phenol = 0.001 mg / l; formaldegid = 0.007 mg / l. Mixing ratio runoff from
river water in the village of T = 0.04 T village population uses river water for drinking.
Decision task №2
Find permissible concentration of aniline in the river, already containing formaldehyde
(0.007) if payment not carry a fraction of the MPC, as a percentage:
Given that the water of the river will be safe only if the sum of the concentrations of
active ingredients similarly expressed as a percentage of approved MAC will not exceed
100%, and the actual concentration of formaldehyde is 70% of his MPC, the allowable
concentration of aniline is 30% of its approved .
30% 0.1 mg / L = 0.03 mg / l
pollution
Actual mg / l
Limit.
Approved. The
actual Permissible
showing
MPC mg MPC
from end-to-%
/l
formaldehyde
0,007
sanitary
- 0,01
remote
70 %
toksichesky
aniline
sanitary
- 0,1
30 %
toksichesky
100 %
0,03