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ROLE OF LAKE SEDIMENTS IN
GROUNDWATER QUALITY
SPONSORERS:
 All India Council for Technical Education (AICTE)
◦ Role of Lake sediments in Ground water quality – TAPTEC
...
RESEARCH CONDUCTED SO FAR &
IDENTIFICATION OF PROBLEM
 Studies limited to assessment of quality
 Theoretical calculation...
Noor Mohammad Kunta, Pink Colour due to discharge of untreated effluents from dyeing industries
OBJECTIVES
• To study the land use practices in the catchment area
• To determine the water quality of incoming nallahs, L...
PROBLEMS FACED BY URBAN LAKES
• Urbanization, Industrialization and
Encroachments
• Tampering of Inflow and Outflow
Channe...
• Cattle Wash • Washing Clothes
• Indiscriminate dumping of Waste • Continuous Flow of Untreated Waste
Water
• Invasive Weed • Pollution due to Idol Immersion
IMPACTS ON LAKE
 Loss of water storage capacity
 Frequent flooding
 Lake water contamination
 Ground water Pollution?
...
STUDIES CONDUCTED
Land Use Practices
Catchment Area of Hussain Sagar Lake
Salient Features of the Lake:
S.No Parameter Specification
1 Year of Construction 1562 AD
2 Catchment Area Classification
...
Bathymetric contour map and Inlet and outlet nallas of Hussain sagar Lake (HUDA 2005)
Ground, Surface Water and sediment Sampling Locations in and around Hussain
Sagar Lake
SAMPLING LOCATIONS
Analysis of Samples Collected from the four Nallahs and the Lake
Parameter
Inlet Nullahs Outlet Nullahs (Lake)
Min Max Min...
Dissolved solids, TSS and Hardness pH, DO & Other Dissolved solids
CONCENTRATIONS OF POLLUTANTS IN INLET AND OUTLET NALLAHS
GPS used for navigation
GPS Hand rover
Collection of water samples using Water Sampler
NAVIGATION AND SAMPLING IN THE ALKE
Table 5: Lake Water Quality Parameters
Pramaeter Min Max Mean
pH 8.2 8.4 8.3
Conductivity (mhos/ cm) 1000 1120 1063.33
Chl...
1
0.5
0.6
0
0.3
0.37
0.65
0.38
0.40
0
0.2
0.4
0.6
0.8
1
1.2
Phosphates Lead Chromium
Concentrationinmg/lit)
Pollutants
Max...
Hardness, Chlorides and Conductivity pH and Dissolved Solids
1120
212
360
290
186
1000
116
232
110
14
1063.33
145.73
281
1...
PROGRESSIVE DETERIORATION OF THE LAKE
Variation in Physico-Chemical Characteristics of Hussain Sagar Lake since 1977
Param...
Variation in Physico-Chemical Parameters of Hussain Sagar Lake water
during different years, a, b- Pollutants with increas...
COLLECTION AND STORAGE OF SEDIMENT SAMPLES
Collection of surface sediment samples using Ekman Grab Sampler
Collection of d...
Collection and Storage of Core sediment Samples
.
Extraction of Pore water from sediments
 Pore water samples were extrac...
Parameter Min Max Mean
pH 7.7 8.2 7.88
Chlorides (ppm) 4 36.4 11.65
Sulphates (ppm) 5 38 17.99
Hardness (ppm) 52 152 97.53...
Concentrations of Pollutants in Sediments in ppm
8.2
36.4 38
152
80
72
55
64
17 8
74
7.88 11.65
17.99
97.53
52.62
44.92
15...
120
177.3
63
72.2
10 7.9
19
3.8
58.92
45.5
39.20
29.5
0
20
40
60
80
100
120
140
160
180
200
Zinc © Zinc (G) Lead © Lead (G...
Parameter Min Max Mean
pH 7.0 7.5 7.13
Conductivity (μ mho/cm) 1260 3860 2179.2
Chlorides (ppm) 100 375 113
Sulphates (ppm...
Graph showing the concentration of Pollutants in Pore Water
Hardness and Conductivity Dissolved Solids
3860
4850
1220
3630...
Variation in Pb, Zn concentrations in Grab, Core, Pore water of sediments
0.04
72.2 63
0.2
177.3
120
1.10.005 3.8
19
0 7.9...
Parameter
Year of Study
1998 2003 2008
pH 7.88 - 8.0
Mercury (ppm) - 2.07 24.58
Chromium (ppm) 46.14 77.65 -
Zinc (ppm) 67...
Ground water sampling locations and contours of Ground water
table around Hussain Sagar Lake.
GROUND WATER SAMPLING LOCATI...
Parameter Max Min Mean
pH 7.9 6.6 7.32
Conductivity (μ mho/cm) 8770 476 2207.9
Chlorides (ppm) 740 36 198.69
Sulphates (pp...
Graph showing the concentration of Pollutants in Ground Water
Conductivity and Hardness Dissolved Solids
8770
1380 1530
22...
0.07
26
1.3
7.9
0.065 1.666
0.038
7.32
0
0
0.08
6.6
0
5
10
15
20
25
30
Lead Potassium Phosphates pH
Concentrationinppm(exc...
Parameters
Inlet Nallah Lake Sediments* Pore water Ground Water
Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Mi...
a
b
Graphical Representation for variation in concentration of
Pollutants in Lake, Sediment, Pore and Ground Water
c
Ground water sampling locations and Hydraulic gradient of Ground water table around the Lake
along with the streams select...
Variation in Chlorides concentration along water flow path
Stream A Stream B
530
325
36
375
180
154
128
108112
293
4
100
3...
Stream C Stream D
530
325
36
375
262
240 195
160
112 116
4
100
321
293
12
113
0
100
200
300
400
500
600
Concentrationinmg/...
Stream A Stream B
295
75.6
38
13
76
60
48 39
26
12 5 3
163
23.6218
80
25
50
75
100
125
150
175
200
225
250
275
300
325
Con...
Stream C Stream D
295
75.6
38
13
84
76 74 72
26
12 5 3
163
23.62 18
80
25
50
75
100
125
150
175
200
225
250
275
300
325
Co...
Stream A Stream B
380 360
152
4850
480 440 420 370
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
3300
3600
3900
4200
45...
Stream C Stream D
380
360 152
4850
860
570 540
370325 281
98
2117
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000
5500
...
Stream A Stream B
76
55
300
24.6 18.3 12 10.3
71
8
120
73.56
15.46
175.38
0
50
100
150
200
250
300
350
Concentrationinmg/l...
Stream C Stream D
76
55
300
13.3 11.3 9.3 7.5
71
8
120
73.56
15.46
175.38
0
50
100
150
200
250
300
350
Concentrationinmg/l...
SOIL COLUMN STUDIES
Experimental Setup
Concentration Factor obtained
(f) = (C) = 0.78
(C0)
FIELD STUDIES AND RESULTS
Ground water sampling locations, contours of chlorides concentration around Hussain Sagar
Lake a...
 The Concentration
factor obtained from the
Experiment Model
conducted on Soil
Column Experiment is
almost equal to the
c...
MATHEMATICAL MODEL
 The analytical equation
representing solute flow in the
aquifer used for the study is
(Fetter,1994):
...
Comparison of Solute Concentrations obtained from Field data and Mathematical model values
Comparison of Solute Concentrations obtained from Field data and Mathematical model values
POLLUTION CONTROLAND REMEDIAL MEASURES
The reasons for contamination of lakes are attributed to
 Discharge of untreated /...
PERFORMANCE STUDIES
Sanghi Polyesters Ltd.
Effluent Treatment Plant Process Flow Diagram
 Domestic sewage from the nearby colony (about 3600Cum/day) is added to
the industrial wastewater (1200Cum/day) in the ra...
Day
TSS removal
Efficiency of
clariflocculator (%)
BOD removal Efficiency
of Aeration Tank (%)
COD removal Efficiency of
A...
Jeedimetla Effluent Treatment Ltd
a) Raw effluent is collected in two equalization and neutralization tanks after
removing...
 Variation in concentration of various parameters in the inlet and outlet of the
treatment plant during year 1999.
Table ...
PILOT PLANT STUDIES ON KATTEDAN INDUSTRIAL EFFLUENT
Experimental setup of Pilot Plant consisting of Influent tank the Reac...
Characteristics of individual and combined effluents
S.No Parameter Textile Edible Oil Dairy Combined
1 pH 7 – 7.5 8 – 8.9...
Design parameters of continuous flow stirred tank aerobic reactor
S.No Parameter Value
1 Volume of the reactor, l 4.5
2 Fl...
 The variation in the BOD & COD concentrations
 The BOD and COD removal efficiencies of the reactor during the study per...
CONCLUSION
 Steady growth of pollutant levels over a period of time indicating increased human
activity in the catchment ...
 The Performance Studies conducted on Sanghi Polymers indicates that Suspended
Solid removal efficiency varied from 69.8%...
COMMENTS BY THE REVIEWERS ON THE THESIS AND REPLIES BY THE SCHOLAR
S.No Comments by the Examiner Response by the Scholar
C...
Chapter - 3
1
In this Chapter, details on the hydrology, hydrogeology and land use
practices of the catchment and downstre...
Chapter - 5
1
This is a very small chapter and it could fit into the chapter-4 (sample
collection and analyses). The ratio...
4
I have serious reservations on the way the solute transport model is
made. Before adopting any model, the candidate need...
Specific questions for Viva-Voce Examination
1
Why the results of “choosen” mathematical model
on pollutant mobility are v...
ROLE OF LAKE SEDIMENTS IN GROUND WATER QUALITY (18.06.2013) (Final)
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ROLE OF LAKE SEDIMENTS IN GROUND WATER QUALITY (18.06.2013) (Final)

  1. 1. ROLE OF LAKE SEDIMENTS IN GROUNDWATER QUALITY
  2. 2. SPONSORERS:  All India Council for Technical Education (AICTE) ◦ Role of Lake sediments in Ground water quality – TAPTEC ◦ Pilot plant studies on the treatability of combined industrial effluent – MODROB  Andhra Pradesh State Council of Science and Technology (APCOST) PRILIMINARY INVESTIGATIONS:  Water Quality of Inlet, Outlet Nallahs and the Lake  Environmental Survey of Kattedan Industrial Area
  3. 3. RESEARCH CONDUCTED SO FAR & IDENTIFICATION OF PROBLEM  Studies limited to assessment of quality  Theoretical calculations on nutrient load  Reduction in size of the lake  Budha poornima accident & Impact of sediments  Lack of detailed information on Lake sediments  Deterioration of Ground water quality  Relation between sediments and ground water quality not established  Lack of Information & commitment on measures to be taken for remediation
  4. 4. Noor Mohammad Kunta, Pink Colour due to discharge of untreated effluents from dyeing industries
  5. 5. OBJECTIVES • To study the land use practices in the catchment area • To determine the water quality of incoming nallahs, Lake, outlet, surrounding ground water, Sediments and Pore water and to study progressive deterioration of lake • To study variation in water quality during its journey • Conducting soil column studies • Application of mathematical model • Conduct performance studies on CETPs • Pilot plant studies on the treatability of combined industrial effluent • Suggest remedial measures
  6. 6. PROBLEMS FACED BY URBAN LAKES • Urbanization, Industrialization and Encroachments • Tampering of Inflow and Outflow Channels & Improper design
  7. 7. • Cattle Wash • Washing Clothes
  8. 8. • Indiscriminate dumping of Waste • Continuous Flow of Untreated Waste Water
  9. 9. • Invasive Weed • Pollution due to Idol Immersion
  10. 10. IMPACTS ON LAKE  Loss of water storage capacity  Frequent flooding  Lake water contamination  Ground water Pollution?  Loss of aquatic species  Loss of traditional Livelihood like fishing  Loss of recreational opportunities  Loss of aesthetics  Release of volatile gases and foul smell – air pollution.
  11. 11. STUDIES CONDUCTED Land Use Practices Catchment Area of Hussain Sagar Lake
  12. 12. Salient Features of the Lake: S.No Parameter Specification 1 Year of Construction 1562 AD 2 Catchment Area Classification Area of built up land (class – 1) 90 Sq Km Area of built up land (class – 2) 68 Sq Km Area of scrub forests 18 Sq Km Area of crop lands 12.5 Sq Km Area of lands with scrub 35 Sq Km Area of lands without scrub 8.5 Sq Km Area of water bodies 8 Sq Km Total 240 Sq Km 3 Maximum water spread area 5.7 Sq km 4 Volume of lake 28.6 X 106 m3 5 Average depth at full capacity 5.02 m 6 Shoreline length 14 Km Hydrological Data of Hussain Sagar Lake Water
  13. 13. Bathymetric contour map and Inlet and outlet nallas of Hussain sagar Lake (HUDA 2005)
  14. 14. Ground, Surface Water and sediment Sampling Locations in and around Hussain Sagar Lake SAMPLING LOCATIONS
  15. 15. Analysis of Samples Collected from the four Nallahs and the Lake Parameter Inlet Nullahs Outlet Nullahs (Lake) Min Max Min Max pH 6.9 8.5 7.8 8.1 Conductivity (mhos/cm) 2170 3600 2550 2700 Chlorides (ppm) 112 530 387 496 Sulphates (ppm) 26 299 235 340 Phosphates (ppm) 0.03 1.6 1.2 2.6 Hardness (ppm) 270 380 - - Alkalinity (mg/lit) 432 560 - - COD (mg/lit) 496 1120 107 186 BOD (mg/lit) 225 373.3 4 70 DO (mg/lit) 0 2.7 - - TSS (mg/lit) 150 540 30 54 TDS (mg/lit) 980 2110 974 1242 Turbidity (NTU) 19 90 Nitrates (mg/lit) 58 85 7.24 13.7 Fluorides (mg/lit) 0.5 1 - - WATER QUALITY IN INLET & OUTLET NALLAHS
  16. 16. Dissolved solids, TSS and Hardness pH, DO & Other Dissolved solids CONCENTRATIONS OF POLLUTANTS IN INLET AND OUTLET NALLAHS
  17. 17. GPS used for navigation GPS Hand rover Collection of water samples using Water Sampler NAVIGATION AND SAMPLING IN THE ALKE
  18. 18. Table 5: Lake Water Quality Parameters Pramaeter Min Max Mean pH 8.2 8.4 8.3 Conductivity (mhos/ cm) 1000 1120 1063.33 Chlorides (mg/l) 116 325 145.73 Sulphates (mg/l) 12 40 21.28 Phosphates (mg/l) 0 1 0.65 Hardness (mg/l) 232 360 281 Calcium Hardness (mg/l) 110 290 186.87 Magnesium Hardness (mg/l) 14 186 87.87 Sodium (ppm) 71 76 73.56 Calcium (ppm) 44 122 75.37 Magnesium (ppm) 3.3 46 21.25 Lead (mg/l) 0.3 0.5 0.38 Chromium (mg/l) 0.3 0.5 0.368 QUALITY OF LAKE WATER
  19. 19. 1 0.5 0.6 0 0.3 0.37 0.65 0.38 0.40 0 0.2 0.4 0.6 0.8 1 1.2 Phosphates Lead Chromium Concentrationinmg/lit) Pollutants Max Min Mean PHOSPHATE AND HEAVY METALS CONCENTRATION IN LAKE
  20. 20. Hardness, Chlorides and Conductivity pH and Dissolved Solids 1120 212 360 290 186 1000 116 232 110 14 1063.33 145.73 281 186.875 87.87 0 200 400 600 800 1000 1200 Concentrationinmg/litexceptEC(μmho/cm) Pollutants Max Min Mean 8.4 40 76 122 46 8.2 12 71 44 3.3 8.3 21.28 73.56 75.37 21.256 0 20 40 60 80 100 120 140 Concentrationinppm(exceptpH) Pollutants Max Min Mean CONCENTRATIONS OF POLLUTANTS IN LAKE WATER
  21. 21. PROGRESSIVE DETERIORATION OF THE LAKE Variation in Physico-Chemical Characteristics of Hussain Sagar Lake since 1977 Parameters Year of Study 1977 1979 1985 1986 1988 1991 1992 1998 2005 2007 pH 8.7 8.1 7.1 8 7.5 8 8 8.3 9.3 7.56 Electronic Conductivity (µmho’s/cm) 1567 2314 2687 3780 3310 1899 2310 1516 1480 2133 Turbidity (NTU) 48 12.5 67 84 72 162 183 210 192 160 Total Suspended Solids (mg/l) 10.6 9 11.67 12 12 16 22 25 28 31 Total Dissolved Solids (mg/l) 935 1254 1363.33 1023 1352 1234 1037 974 1134 1242 Alkalinity (mg/l) 347.8 360 328 420 220 206 250 369 457 587 Chlorides (mg/l) 166.2 183 263.3 390 260 201 245 212 312 390 Total Hardness (mg/l) 288 296 254 301 325 314 317 360 382 367 Nitrates (mg/l) 0.37 2.5 2.7 3.22 4.35 5.48 7.5 10.47 9 13.7 Sulphates (mg/l) 117 108 137.3 159.2 120 137.9 90 75.6 92.58 136 Phosphates (mg/l) 1.05 0.82 0.66 5.85 5.75 6.08 6.7 0.93 9.2 13.6 Chemical Oxygen Demand (mg/l) - - 81.33 85.2 89 123 140 170.67 165 237 Biological Oxygen Demand (mg/l) - - 30.33 35.2 40 42 53.75 70 64 85
  22. 22. Variation in Physico-Chemical Parameters of Hussain Sagar Lake water during different years, a, b- Pollutants with increasing Trend. c- Pollutants with Random Trend Turbidity TSS Alkalinit y Hardness Nitrates Phospates COD BOD pH EC TDS Cl Sulphate s
  23. 23. COLLECTION AND STORAGE OF SEDIMENT SAMPLES Collection of surface sediment samples using Ekman Grab Sampler Collection of deep sediments using Kajak – Brinkhurst Core Sampler
  24. 24. Collection and Storage of Core sediment Samples . Extraction of Pore water from sediments  Pore water samples were extracted from the sediments using filter presses and centrifuge and then filtered through wattman filter paper using vacuum filtration techniques before analysis.
  25. 25. Parameter Min Max Mean pH 7.7 8.2 7.88 Chlorides (ppm) 4 36.4 11.65 Sulphates (ppm) 5 38 17.99 Hardness (ppm) 52 152 97.53 Calcium Hardness (ppm) 16 80 52.62 Magnesium Hardness (ppm) 20 72 44.92 Sodium (ppm) 8 55 15.46 Calcium (ppm) 13 64 25.47 Magnesium (ppm) 5 17 10.82 Potassium (ppm) 4 8 6 Chromium (mg/kg) 20 74 42.81 QUALITY OF SEDIMENTS
  26. 26. Concentrations of Pollutants in Sediments in ppm 8.2 36.4 38 152 80 72 55 64 17 8 74 7.88 11.65 17.99 97.53 52.62 44.92 15.46 25.47 10.82 6 42.81 7.7 4 5 52 16 20 8 13 5 4 20 0 20 40 60 80 100 120 140 160 Pollutants Max Mean Min
  27. 27. 120 177.3 63 72.2 10 7.9 19 3.8 58.92 45.5 39.20 29.5 0 20 40 60 80 100 120 140 160 180 200 Zinc © Zinc (G) Lead © Lead (G) Concentrationinmg/kg Pollutants Max Min Mean G – Grab C- Core Parameter Core Samples Grab Samples Min Max Mean Min Max Mean Zinc (mg/kg) 10 120 58.92 7.9 177.3 45.5 Lead (mg/kg) 19 63 39.2 3.8 72.2 29.5 CONCENTRATION OF HEAVY METALS IN SEDIMENTS
  28. 28. Parameter Min Max Mean pH 7.0 7.5 7.13 Conductivity (μ mho/cm) 1260 3860 2179.2 Chlorides (ppm) 100 375 113 Sulphates (ppm) 2.5 13 7.84 Hardness (ppm) 1275 4850 2117.3 Calcium Hardness (ppm) 300 1220 498.46 Magnesium Hardness (ppm) 995 3630 1627.3 Sodium (ppm) 120 300 175.38 Calcium (ppm) 120 488 199.38 Magnesium (ppm) 231 878 392.38 Lead (ppm) 0 0.2 0.133 Potassium (ppm) 20 69 33.92 Phosphates (ppm) 0.005 0.04 0.016 Zinc (ppm) 0 1.1 0.315 QUALITY OF PORE WATER
  29. 29. Graph showing the concentration of Pollutants in Pore Water Hardness and Conductivity Dissolved Solids 3860 4850 1220 3630 1260 1275 300 995 2179.2 1744 498.5 1627.3 0 1000 2000 3000 4000 5000 6000 Concentrationinppm Pollutants Max Min Mean a 375 300 488 878 69 100 120 120 231 20 113 175.4 199.4 393 34 0 100 200 300 400 500 600 700 800 900 1000 Cl- Na Ca+ Mg+ K Concentrationinppm Pollutants Max Min Mean b
  30. 30. Variation in Pb, Zn concentrations in Grab, Core, Pore water of sediments 0.04 72.2 63 0.2 177.3 120 1.10.005 3.8 19 0 7.9 10 0 0.016 29.5 39.2 0.133 45.5 58.92 0.315 0 20 40 60 80 100 120 140 160 180 200 Concentrationinppm Pollutants Max Min Mean G – Grab C- Core P - Pore 7.88 11.65 17.99 7 15.5 42.81 39.2 58.92 7.13 113 7.84 34 175.4 0.13 0.315 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 160 170 180 190 pH Cl- So42- K Na Cr Pb Zn Concentrationinppm(except pH) Pollutants Lake Sediment Pore water Variation in Dissolved solids concentrations in Sediment and Pore Water 98 45 52.6 25.5 10.8 2117.3 1627 498 199.4 393 0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 Hardness Mg Hardness Ca Hardness Ca+ Mg+ Concentration(ppm) Pollutants Lake Sediment Pore Water
  31. 31. Parameter Year of Study 1998 2003 2008 pH 7.88 - 8.0 Mercury (ppm) - 2.07 24.58 Chromium (ppm) 46.14 77.65 - Zinc (ppm) 67.99 280.28 - Lead (ppm) 45.23 146.5 120.8 Arsenic (ppm) - 15.95 72.24 0 20 40 60 80 100 120 140 160 180 200 220 240 260 280 300 pH Mercury Chromium Zinc Lead Arsenic Concentrationinppm(exceptpH) Pollutants 1998 2003 2008 INCREASE OF HEAVY METAL CONCENTRATION IN LAKE SEDIMENTS OVER A DECADE
  32. 32. Ground water sampling locations and contours of Ground water table around Hussain Sagar Lake. GROUND WATER SAMPLING LOCATIONS & CONTOURS
  33. 33. Parameter Max Min Mean pH 7.9 6.6 7.32 Conductivity (μ mho/cm) 8770 476 2207.9 Chlorides (ppm) 740 36 198.69 Sulphates (ppm) 340 10 81.64 Hardness (ppm) 1530 170 525.32 Alkalinity (ppm) 816 168 422.1 Sodium (ppm) 53.3 2.6 15.62 Calcium (ppm) 1380 110 398.59 Magnesium (ppm) 420 15 151.07 Lead (ppm) 0.07 0 0.065 Potassium (ppm) 26 0 1.666 Phosphates (ppm) 1.3 0.08 0.038 GROUND WATER QUALITY
  34. 34. Graph showing the concentration of Pollutants in Ground Water Conductivity and Hardness Dissolved Solids 8770 1380 1530 2207.9 398.59 525.32476 110 1700 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 Conductivity Calcium Hardness Concentrationinppm(exceptConductivity) Pollutants Max Mean Min 740 340 816 53.3 420 198.69 81.64 422.1 15.62 151.07 36 10 168 2.6 150 100 200 300 400 500 600 700 800 900 Concentrationinppm Pollutants Max Mean Min
  35. 35. 0.07 26 1.3 7.9 0.065 1.666 0.038 7.32 0 0 0.08 6.6 0 5 10 15 20 25 30 Lead Potassium Phosphates pH Concentrationinppm(exceptpH) Pollutants Max Mean Min Graph showing the concentration of Various Pollutants in Ground Water
  36. 36. Parameters Inlet Nallah Lake Sediments* Pore water Ground Water Max Min Mean Max Min Mean Max Min Mean Max Min Mean Max Min Mean Alkalinity (mg/l) 560 432 507 372 320 369.3 - - - - - - 816 168 422.1 Sulphates (mg/l) 295 26.0 163 75.6 12.0 23.62 38.0 5.0 18.0 13.0 2.5 7.8 340 10.0 81.6 Chlorides (mg/l) 530 112 321 212 116 145.7 36.4 4.0 11.7 375 100 113 740 36.0 198.7 Hardness (mg/l) 380 270 325 360 232 281 152 52.0 97.5 4850 1275 2117.3 1530 170 525.3 Sodium (ppm) - - - 76.0 71.0 73.6 55.0 8.0 15.5 300 120 175.4 53.3 2.6 15.6 Potassium (mg/l) - - - - - - 15.0 4.0 7.0 69.0 20.0 33.9 26.0 0 1.7 Ca Ions (ppm) - - - 122 44.0 75.4 64.0 13.0 25.5 488 120 199.4 1380 110 398.6 Mg Ions (mg/l) - - - 46.0 3.3 21.3 17.0 5.0 10.8 878 231 393.0 420 15.0 151.1 Ca Hardness (mg/l) - - - 290 110 186.9 80.0 16.0 52.6 1220 300 498.5 - - - Mg Hardness (mg/l) - - - 186 14.0 87.9 72.0 20.0 44.9 3630 995 1627.3 - - - Lead (mg/l) - - - 0.5 0.3 0.4 63.0 19.0 39.2 0.2 0 0.1 0.07 0 0.063 Chromium (mg/l) - - - 0.6 0.4 0.4 74.0 20.0 42.8 BDL BDL - BDL BDL - Fluorides (mg/l) 1.0 0.5 0.75 - - - - - - - - - 1.8 0.3 1.1 Cadmium (mg/l) - - - - - - 9.0 5.0 6.8 BDL BDL - 0.01 0 0.001 Zinc (mg/l) - - - 2.0 1.5 1.75 10.0 120 58.9 1.1 0 0.3 BDL BDL - * Values in mg/kg Variation in Concentration of Pollutants in Inlet, Lake, Sediments and Groundwater
  37. 37. a b
  38. 38. Graphical Representation for variation in concentration of Pollutants in Lake, Sediment, Pore and Ground Water c
  39. 39. Ground water sampling locations and Hydraulic gradient of Ground water table around the Lake along with the streams selected for study. IMPACT OF LAKE SEDIMENTS ON GROUND WATER QUALITY
  40. 40. Variation in Chlorides concentration along water flow path Stream A Stream B 530 325 36 375 180 154 128 108112 293 4 100 321 116 12 113 0 100 200 300 400 500 600 Concentrationinmg/lit Sample Locations Max Min Mean 530 325 36 375 105 88 72.5 57 112 293 4 100 321 116 12 113 0 100 200 300 400 500 600 Concentrationinmg/lit Sample Locations Max Min Mean
  41. 41. Stream C Stream D 530 325 36 375 262 240 195 160 112 116 4 100 321 293 12 113 0 100 200 300 400 500 600 Concentrationinmg/lit Sample Locations Max Min Mean 530 325 36 375 232 224 192 160 112 116 4 100 321 293 12 113 0 100 200 300 400 500 600 Concentrationinmg/lit Sample Locations Max Min Mean Variation in Chlorides concentration along water flow path
  42. 42. Stream A Stream B 295 75.6 38 13 76 60 48 39 26 12 5 3 163 23.6218 80 25 50 75 100 125 150 175 200 225 250 275 300 325 Concentrationinmg/lit Sample Locations Max Min Mean 295 75.6 38 13 80 72 64 52 26 12 5 3 163 23.62 18 80 25 50 75 100 125 150 175 200 225 250 275 300 325 Concentrationinmg/lit Sample Locations Max Min Mean Variation in Sulphates concentration along water flow path
  43. 43. Stream C Stream D 295 75.6 38 13 84 76 74 72 26 12 5 3 163 23.62 18 80 25 50 75 100 125 150 175 200 225 250 275 300 325 Concentrationinmg/lit Sample Location Max Min Mean 295 75.6 38 13 190 146 96 75 26 12 5 3 163 23.62 18 80 25 50 75 100 125 150 175 200 225 250 275 300 325 Concentrationinmg/lit Sample Location Max Min Mean Variation in Sulphates concentration along water flow path
  44. 44. Stream A Stream B 380 360 152 4850 480 440 420 370 0 300 600 900 1200 1500 1800 2100 2400 2700 3000 3300 3600 3900 4200 4500 4800 5100 Concentrationinmg/lit Sample Locations Max Min Mean 380 360 152 4850 680 530 380 320325 281 98 2117 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 Concentrationinmg/lit Sample Locations Max Min Mean Variation in Hardness concentration along water flow path
  45. 45. Stream C Stream D 380 360 152 4850 860 570 540 370325 281 98 2117 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 Concentrationinmg/lit Sample Locations Max Min Mean 380 360 152 4850 470 385 300 325 281 98 2117 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 Concentrationinmg/lit Sample Locations Max Min Mean 480 Variation in Hardness concentration along water flow path
  46. 46. Stream A Stream B 76 55 300 24.6 18.3 12 10.3 71 8 120 73.56 15.46 175.38 0 50 100 150 200 250 300 350 Concentrationinmg/lit Sample Locations Max Min Mean 76 55 300 13.2 10.6 8.9 7.2 71 8 120 73.56 15.46 175.38 0 50 100 150 200 250 300 350 Concentrationinmg/lit Sample Locations Max Min Mean Variation in Sodium concentration along water flow path
  47. 47. Stream C Stream D 76 55 300 13.3 11.3 9.3 7.5 71 8 120 73.56 15.46 175.38 0 50 100 150 200 250 300 350 Concentrationinmg/lit Sample Locations Max Min Mean 76 55 300 18.6 14.6 12.6 8.6 71 8 120 73.56 15.46 175.38 0 50 100 150 200 250 300 350 Concentrationinmg/lit Sample Locations Max Min Mean Variation in Sodium concentration along water flow path
  48. 48. SOIL COLUMN STUDIES Experimental Setup Concentration Factor obtained (f) = (C) = 0.78 (C0)
  49. 49. FIELD STUDIES AND RESULTS Ground water sampling locations, contours of chlorides concentration around Hussain Sagar Lake and stream lines considered for comparative analysis
  50. 50.  The Concentration factor obtained from the Experiment Model conducted on Soil Column Experiment is almost equal to the concentration factor between two consecutive sampling points in a certain stream path which flows in downstream direction. Sample Points Field Values C/C0 Streamline A-A 0.84 48 154 0.86 39 128 0.83 40 108 0.84 Streamline B - B 0.76 46 130 57 88 0.68 42 72.5 0.82 41 57 0.78 Streamline C - C 0.8 30 296 0.76 31 240 0.81 33 195 0.81 52 160 0.82 Streamline D - D 0.82 25 224 0.78 26 192 0.86 27 160 0.83 Field observations of Chlorides concentration in ground water samples of respective streams and C/Co values
  51. 51. MATHEMATICAL MODEL  The analytical equation representing solute flow in the aquifer used for the study is (Fetter,1994): Sample Points Field Values Mathematic al Model Values Streamline A-A 48 154 147 39 128 137 40 108 132 Streamline B - B 46 130 168 57 88 160 42 72.5 135 41 57 132 Streamline C - C 30 296 169 31 240 166 33 195 147 52 160 127 Streamline D - D 25 224 141 26 192 136 27 160 128 Comparison of mathematical model results with field data
  52. 52. Comparison of Solute Concentrations obtained from Field data and Mathematical model values
  53. 53. Comparison of Solute Concentrations obtained from Field data and Mathematical model values
  54. 54. POLLUTION CONTROLAND REMEDIAL MEASURES The reasons for contamination of lakes are attributed to  Discharge of untreated / partially treated complex industrial effluents in to lakes through inlet nallahs.  Inadequate sewage treatment facilities for the treatment of domestic sewage entering the lake.  Indiscriminate disposal of solid waste in the catchments of nallahs carrying water to the lake  Improper maintenance of drains / nallahs, which accumulate silts and solid waste throughout the year and flows in to the lake in huge volumes during floods.  Immersion of Idols and dumping of material used for worship and  Washing of cloths, cattle etc.
  55. 55. PERFORMANCE STUDIES Sanghi Polyesters Ltd. Effluent Treatment Plant Process Flow Diagram
  56. 56.  Domestic sewage from the nearby colony (about 3600Cum/day) is added to the industrial wastewater (1200Cum/day) in the ratio of 3:1 directly in contact chamber to increase the bacterial content. Variation in quality parameters of untreated and treated effluents are listed in Tables below. Characteristics Raw water Treated water pH COD (mg/l) BOD (mg/l) Total Hardness (mg/l) Calcium Hardness (mg/l) Alkalinity (mg/l) Total Suspended Solids (mg/l) Total dissolved Solids (mg/l) 7 to 10 550Mg/1-1450 100Mg/l-300 200-2300 150-1200 600-1400 140-171 800-2200 7 to 8 100-235 20-28 790-2400 290-1340 690-930 69-82 1890-2090 Characteristics of Raw and Treated water of the CETP
  57. 57. Day TSS removal Efficiency of clariflocculator (%) BOD removal Efficiency of Aeration Tank (%) COD removal Efficiency of Aeration Tank (%) 1st 2nd 3rd 4th 5th 6th 7th 8th 72.0 71.0 72.0 75.0 70.0 74.8 69.8 71.2 83.0 80.3 69.7 87.2 52.4 74.8 66.1 77.4 83.5 80.3 88.8 88.9 50.0 74.7 66.1 77.4 Total Suspended Solid removal efficiency of clarifloculator and BOD & COD removal efficiencies of aeration tank during study period
  58. 58. Jeedimetla Effluent Treatment Ltd a) Raw effluent is collected in two equalization and neutralization tanks after removing the floating material using screens. b) Raw water is then pumped into the flash mixer unit after neutralizing with lime/NaOH. c) Rapid mixing of coagulants (polyelectrolyte) with effluents was done, for the formation of flocks and then the effluent flows into the Clarifloculator by gravity. d) Settled sludge from the clarifier is sent into sludge thickener and then to centrifuge where the liquid and the sludge separation takes place. e) The liquid effluent from Overflow sump reaches to Diffused air flotation (DAF), where the fine suspended particles are removed by air floatation using compressed air. f) The sewage in the Distribution Chamber is mixed thoroughly with effluent in 2: 11/2 ratio and then pumped to the ASP unit. g) With the help of Mechanical Aerators provided in the aeration tank the microorganisms present in the combined effluent consumes oxygen and stabilize the organic matter. h) The effluent from the ASP then reaches the Final Clarifier. The average discharge of treated effluent is 3300 cum/day.
  59. 59.  Variation in concentration of various parameters in the inlet and outlet of the treatment plant during year 1999. Table shows the range of concentration of various inlet and outlets of the plant. Parameter Inlet Outlet pH 7.4 - 8.2 7.1 - 7.9 Total Dissolved Solids 49990 - 55000 21000 - 25370 Suspended Solids 210 - 320 33 - 90 COD 10880 - 12160 2172 - 2614 BOD 3400 - 3952 40.4 - 73.6
  60. 60. PILOT PLANT STUDIES ON KATTEDAN INDUSTRIAL EFFLUENT Experimental setup of Pilot Plant consisting of Influent tank the Reactor and Effluent collection tank
  61. 61. Characteristics of individual and combined effluents S.No Parameter Textile Edible Oil Dairy Combined 1 pH 7 – 7.5 8 – 8.9 7.3 – 7.8 7 – 8 2 Colour Pale yellow Pale yellow White Brown 3 Temperature, ° C 35 32 30 28 4 COD, mg/l 2890 – 3010 2500 – 9000 1940 – 3050 1400 – 8600 5 BOD, mg/l 1000 – 1200 800 – 4000 900 – 2000 1500 – 1700 6 Total Solids, mg/l 1650 – 1750 8000 – 8250 1750 – 1900 1750 – 2850 7 Total Suspended Solids, mg/l 77 – 100 4200 – 4300 800 – 950 1550 – 1800 8 Chlorides, mg/l 390 – 420 400 – 450 110 – 140 280 –300 9 Total Alkalinity mg/l 200 –220 115 – 180 190 – 230 160 – 280 10 Total Phosphorous, mg/l - - - 12 – 14 11 Total Kjeldal Nitrogen, mg/l - - - 45-60
  62. 62. Design parameters of continuous flow stirred tank aerobic reactor S.No Parameter Value 1 Volume of the reactor, l 4.5 2 Flow rate, l / day 3 3 Hydraulic Retention Time, q in hrs 36 4 Sludge Retention Time, qc in days 8.2 – 9.6 5 Food to Microorganism ratio, F/M (BOD/VSS) 0.04 – 0.15 6 Rate of Air supply, l / min 1.6 7 Sludge Volume Index, SVI 85 8 COD removal Efficiency ( After 20 days), % 90 9 Mixed Liquor Suspended Solids (MLSS), X in mg/l 6800 -7900 Difference in clarity of untreated and treated effluents of the Pilot plant
  63. 63.  The variation in the BOD & COD concentrations  The BOD and COD removal efficiencies of the reactor during the study period
  64. 64. CONCLUSION  Steady growth of pollutant levels over a period of time indicating increased human activity in the catchment area.  The measures undertook to abate pollution of the lake are inadequate.  Lake acts as a sink for the pollutants entering through incoming Nallahs.  Relatively higher concentrations of Dissolved solids present in the pore water than in the dry sediments.  It was observed Very high concentrations of Electric conductivity in Pore water, High values in Inlet Nallahs, Medium concentrations in near by Ground water and low concentrations in lake water.  The concentration of Chlorides also followed same pattern as conductivity.  High concentrations of Calcium, Magnesium and Hardness were found in pore water, Medium and low concentrations were observed in ground water and lake water respectively indicates accumulation of non-metal concentration in the sediment bed and transportation of the same in to the ground water through infiltration.  High concentrations of Lead, Chromium, Cadmium and Zinc were found in Sediments, Medium concentrations in Lake water and nil concentrations in surrounding ground water, Which indicate accumulation and adsorption of metals in the sediment bed.  Sediment bed acts as filter media for heavy metals and source of pollution for non- metals in ground water. Hence it is evident that sediment bed has a significant role in controlling/contributing to ground water pollution.
  65. 65.  The Performance Studies conducted on Sanghi Polymers indicates that Suspended Solid removal efficiency varied from 69.8% to 75%. The BOD removal efficiency of the plant ranged between 52.4% and 87.2% and the COD removal efficiency varied between 50% and 82.9%.  The Performance Studies conducted on Jeedimetla Effluent Treatment Plant indicate that when compared to the performance of the treatment plant in 1989, 1990 with 1999 the organic removal efficiency of the plant was high in 1999 due to addition of domestic sewage with combined effluent  Mixing of easily biodegradable effluent with complex organic effluents in a common effluent treatment plant would increase the efficiency of the treatment plant resulting reduction in the pollution load on receiving water body.
  66. 66. COMMENTS BY THE REVIEWERS ON THE THESIS AND REPLIES BY THE SCHOLAR S.No Comments by the Examiner Response by the Scholar Chapter - 1 1 Scientific articulation is needed. In a scientific report, usage like "somebody" should be avoided. Complete check for language is required. Modified the thesis with respect to scientific articulation. Also checked and modified for Spellings and Grammar. 2 Reference at critical places is necessary. For eg., classification of Hussain Sagar Lake as Dystrophic lake needs references for both attributes and classification schema. References included and style of representing reference is modified throughout the thesis. 3 Significance of the present investigation needs to be brought out very clearly here. For eg., how different is this work different from the work of Srikanth et al.,(1993), Anitha et al.,(1995), Reddy et al 2001, and Rao, C.S.(2005) carried out on Hussain Sagar?? Elaborated the work carried out by the contemporary researchers, gaps were identified and related with present study. Srikanth et al (1995) compared mercury levels in lake water with the levels in surrounding ground water. There was no mention about sediment quality and its role in transmitting lake pollution to groundwater. Anitha et al (1995) studied the impact of industrial effluent on aquatic life in Hussainsagar lake. It is purely the study related to the biological aspects. Reddy et al (2001) probably the study conducted by the scholar of this work. Rao C.S (2005) conducted studies on the sediment quality of the lake and also carried out Heavy metal speciation study on Hussain sagar lake sediments. Categorization of sediments and role of sediments in transmitting pollutants to ground water is lacking in this report. Chapter - 2 1 The Literature Review chapter is more like a listing of so-and-so has published so-and-so paper. Nowhere, the scientific content of the earlier works are presented in logical and coherent way. This chapter needs a complete overhaul incorporating various components necessary for this investigation like sediment transport, sampling strategy, geo-chemical analyses, and standards adopted in a lucid way. Plethora of literature is available on above aspects and the candidate is expected to group these works under different categories, identify the gaps and highlight the need for the investigated approach. Modified this Chapter as per suggestions of the reviewer. 2 Standard and uniform reference style must be followed throughout the thesis. Modified reference style as per suggestion of the reviewer.
  67. 67. Chapter - 3 1 In this Chapter, details on the hydrology, hydrogeology and land use practices of the catchment and downstream of Hussainsagar is expected. The downstream groundwater details beyond 1 km zone will provide more insight on the effect of continent transport from the reservoir. Hydrology and Land use practices in the catchment area of the lake was obtained through the studies conducted by the self and reports of various organizations (APPCB, HUDA, SAFEGE and AIC etc.) working on the remediation of the lake. Since the research is basically on lake sediments, the scholar concentrated more on the catchment area of the lake, which is the source of pollutants in the lake. 2 What is the basis of arriving at the runoff coefficients? SCS-CN and MUSCLE techniques are more appropriate for estimating the runoff and soil loss potentials. Most of the data presented in this chapter seems to be from some outdated report (dating back to 1990) rather than generated from the candidate. Each table made using data from that report needs to be credited by mentioning it in the caption. Run off coefficients were obtained from APPCB report (1990). Majority of the experimental work was carried out during the years from 1997 to 2000 and few technical literature published during that period was referred. Suggestion of reviewer with regard to source of information is reviewed and implemented 3 What are the sampling strategy and analytical procedures adopted to arrive at Table 3.9? The source of information provided in this table is from "M. Narayana Rao & Amal K. Datta, 'Waste Water Treatment', Second Edition, IBH Publishing Co. Pvt. Ltd (1987) 4 Any map should contain coordinates, scale, legend etc. Both figures 3.1 and 3.2 are not containing any of these details. Modified as per suggestion of the reviewer. Chapter - 4 1 The Chapter heading is not adequately reflecting the contents. Modified per suggestion of the reviewer. 2 Instead of mentioning "standard procedures were adopted", better cite the reference and detail the salient aspects. Modified per suggestion of the reviewer. 3 For how much time samples were sorted before analyses? Whether any precautions were taken to prevent the biological activities and precipitations? Standard methods for examination of water and water analysis, 16th edition (1985), APHA, AWWA, APCF was refered for Collection, storage, transportation and analysis of water samples and USEPA Guidelines for Analysis of Polluted Soils (1994) were followed for Sampling, collection, Transportation, Storage and analysis of water and sediment samples. 4 In page - 50, it is mentioned that along with the other parameter pH was also measured in laboratory. For studies of this kind, Insitu pH are needed? pH of the samples were measured in the laboratory on the same day of collection. 5 Why there is a clustering of water sampling adjoining the bund only? Regular sampling downstream would have been more useful. Groundwater samples collected from the existing bore/open wells available between 0 and 1.5 km from shore line. Since the hydraulic gradient of the groundwater flow was from NWW to SEE, more samples were collected in the downstream of the lake in SEE direction. 6 Figure 4.11: grain size distribution curves are usually plotted on semi-log plots This figure shows percentage of finer particles passing through the specific size of sieve of dry sieve analysis. The sediments obtained by core samplers were used for this analysis. Particles ranging from 4.75 to <0.075 mm were present in these samples and includes sand, silt, clay and organic content.
  68. 68. Chapter - 5 1 This is a very small chapter and it could fit into the chapter-4 (sample collection and analyses). The rational for breaking it as a separate chapter is not clear. As suggested, this chapter is now included in Chapter - 4 2 Figure-5.1: Is this methodology developed by the candidate or already established? If developed by some other worker, reference is needed. Lokesh. “Transmission of Pollutants through Soils into Subsurface water in certain industrial pockets of Karnataka- problems and Litigation”. A thesis submitted to University of Mysore August (2000), was referred before finalizing the methodology 3 Why only one sample collected for this test? Compaction alone may not be the correct criteria. Why important properties like Eh, CEC, sorption, and specification were not considered? One soil sample from Indira park used for the soil analysis and soil column studies. More emphasis was given to Sediment and groundwater quality. From the field data it is evident that there is transportation of elements viz. chlorides, sulphates, sodium and potassium from pore water of sediments to the groundwater and the concentration of these elements decreases from nearest well to the farthest well. The scholar made an attempt to apply suitable model to resemble the change in concentration using a mathematical model and could succeeded in assessing only one pollutant i.e. chlorides. 4 Page-88: Please quantify the "sufficient time" allowed for the saturation of the column with solution. I suppose it is a function of soil type. Soil column was filled with the effluent and soaked the soil column until it gets saturated. Sample collection from the sampling ports was started after achieving constant discharge at the sampling port. This was achieved 38 hours after the soil column was filled with the effluent. Chapter - 6 1 This Chapter is more like presenting the statistics of the data given in earlier chapters rather than scientific processing, analyses and interpretation. The data analyses and rationalizing the scientific aspects are lacking. As observed in the previous chapters, the same data is represented both as a table (Table 6.2, Figure 6.2 a,b,c; Table 6.3, Figures 6.3-6.6) and figure. This may help only in making the thesis bulky. Analytical results of water samples from four Inlet nallahs, two Outlet channels, Lake water, sediment and pore water samples from sixteen locations of Hussain Sagar Lake and groundwater samples from fifty seven locations around the lake were assessed and the results of all the samples were represented in Chapter - 4. Summary of the results with minimum, maximum and mean values of that particular group was analyzed and discussed in this chapter. 2 Many fold increases in dissolved salts between the inlet and outlet nallahs are not reflected by corresponding changes in TDS and conductivity, Why? Table no. 6.1 shows the analytical results of Inlets and outlets. Out of many chemical parameters of water quality, this table only shows parameters like chlorides, sulphates, nitrates etc. Other significant parameters like hardness, alkalinity etc are not accounted for in outlet quality. Since conductivity is the representative parameter for total solids, absence of major parameters like carbonates and bicarbonate may not give true representation. 3 In page no. 102, section 6.4.1: concentration measured from core, grab and pore water samples are compared but no inferences were drawn on the contaminant retention/mobility. Table 6.3 shows Maximum, minimum and mean values of heavy metals in Core, Grab and pore water of sediments. the constituents core sample is nothing but contents of grab sample after removal of pore water from it. The mean values of Heavy metal concentrations in core and grab samples are almost same and there are negligible concentrations in pore water. On the other hand negligible concentrations of heavy metals were observed in groundwater. It indicates that Heavy metals are retained and became part of hardened sediments and there is negligible mobility towards groundwater.
  69. 69. 4 I have serious reservations on the way the solute transport model is made. Before adopting any model, the candidate needs to understand its suitability for the chosen area. (i) What is the representative K value chosen for arriving at V? In the investigated area, aquifers are hard rocks, the transport is mostly channel flow, and not porous media flow. How many layers were considered and what are their hydraulic conductivities? (ii) What are the secular changes in water table gradient and its role in velocity changes? (iii) What are the boundary conditions and their influence? (iv) Why the model was not calibrated and tested? (v) Like K, a is also a function of direction. A single value cannot represent the issue addressed here. In brief, the modeling carried out in this research is over simplified and has no practical significance. This could be the reason for significant deviation between measured and modeled values (Figures 4.6, a-d). The Hydraulic conductivity value 'K' value Chosen was 1.0X105 m/s One of the objectives of the present study is to differentiate sediments in to hard sediments, surface sediments and pore water and find out what type of pollutant accumulate in particular category of sediment. With the field values it was evident that concentrations of non metals viz. Chlorides and sulphates decreased from nearest to farthest ground water well indicating dispersion of these elements present in higher concentrations in pore water of sediments. The scholar did not concentrate much on the dispersion model. Hence the model developed by Fetter 1994, was successfully used to demonstrate dispersion of element chlorides in to groundwater aquifer. 5 Speciation of different pollutants and accordingly their mobility is expected in this chapter. Studies on the speciation of pollutants have already been carried out by Gurunadha Rao et al (2008). The literature on this is included in Chapter – 2 Chapter - 7 1 Conclusion no 1: It should be better to have low COD and BOD. If the outlet values are lower than the inlet values, doesn't it mean dilution in the lake? Yes. Lake is receiving higher concentrations of BOD and COD and getting diluted in the lake and considerably lower values of these elements were present in outlets. Since lake act as a sedimentation tank, these elements undergo decomposition and settle at the bottom of the lake and accumulate in sediments either in pore water or in sediments. This was the reason why higher concentrations of end products of decomposition occur in sediments. 2 A solid conclusion on the specification of pollutants and a practically validated, meaningful numerical dispersion pattern is expected here. Studies on the speciation of pollutants have already been carried out by Gurunadha Rao et al (2008). The literature on this is included in Chapter - 2 Chapter - 8 1 This Chapter seems like an appendage rather than part of the thesis. For any CFSTR, parameters like (i) distribution of residence times in the system, (ii) the quality of mixing, (iii) And the model used to describe the system are very important. No mention is made about these anywhere. This chapter was included as per the advice of the professors present in Research Review meetings conducted by the Civil Engineering Department prior to submission of the thesis.
  70. 70. Specific questions for Viva-Voce Examination 1 Why the results of “choosen” mathematical model on pollutant mobility are very poor and have significant deviation from the measured value? Fetter’s (1994) equation was used to assess analytical values and compared with the field observations and represented in tables 5.8 and 5.9 and in figure 5.16. The trend of observations are almost similar with minor deviation. This deviation is attributed to interferences in the groundwater flow path. 2 Why no attempt was made to investigate the speciation of different pollutants? Studies on the speciation of pollutants have already been carried out by Gurunadha Rao et al (2008). The literature on this is included in Chapter – 2 3 Why the data on chemistry of sediments, Ground water and pore water were not analysed in terms of mass balance? Collection and analysis of samples from Inlet, lake water, outlet, sediments (including surface, core and pore water) and surrounding ground water were carried out over a span of 3 years at different intervals of time and different seasons. The results of mass balance studies may not be representative due to variation in time and concentrations. 4 Why important points like Eh, CEC and sorption were not considered? One soil sample from Indira park used for the soil analysis and soil column studies. More emphasis was given to Sediment and groundwater quality. From the field data it is evident that there is transportation of elements viz. chlorides, sulphates, sodium and potassium from pore water of sediments to the groundwater and the concentration of these elements decreases from nearest well to the farthest well. The scholar made an attempt to apply suitable model to resemble the change in concentration using a mathematical model and could succeed in assessing only one pollutant i.e. chlorides. 5 What are the bases of selecting the single hydraulic conductivity (K) and dispersivity (α) One of the objectives of the present study is to differentiate sediments in to hard sediments, surface sediments and pore water and find out what type of pollutant accumulate in particular category of sediment. With the field values it was evident that concentrations of non metals viz. Chlorides and sulphates decreased from nearest to farthest ground water well indicating dispersion of these elements present in higher concentrations in pore water of sediments. The scholar did not concentrate much on the dispersion model. Hence the model developed by Fetter 1994, was successfully used to demonstrate dispersion of element chlorides in to groundwater aquifer. 6 What is the effect of lake contamination in the groundwater quality of downstream areas? With reference to field observations represented in Table nos.5.7, and 5.9 and Figure nos. 5.10 through 5.14, the pollutant concentration in ground water decreases from nearest well to the farthest well indicating pollutant contribution from contaminated lake. 7 Can any general approaches be suggested for the restoration of so many other lakes in other part of India? Measures for restoration of polluted lakes are described in recommendations in Page no. 156 of the thesis. 8 The relationship of sediment physical properties on its adsorption capacity may be explained? Particle size, porosity and initial pollutant concentration in sediment are the main factors affecting pollutant release through the sediment water interface. If a chemical is adsorbed to sediment particles, it will accumulate in the bed and suspended load of aquatic systems and will not reach groundwater. If a chemical is not adsorbed, it will accumulate in the water column of aquatic system, leach through the sediment profile and may reach groundwater. 9 Bring out the conclusion from column studies? The objective of conducting soil column studies is to find out reduction in concentration of pollutant after passing specific distance through the soil column and compare concentration factors (C/Co) with the field observed values. The concentration factors are presented in Table nos. 5.8 and 5.9. These factors are matching with minor difference. 10 Whether the data from column studies can be used to forecast the groundwater contamination in nearby area? Yes.

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