Mitigation and Remedy of Groundwater Arsenic Menace in India

More documents

Recommendations

Info

Mitigation and Remedy of Groundwater Arsenic Menace in India : A Vision Document(vii)(viii)(ix)(x)(xi)(xiii)(xiv)(xv)All shallow dug well aquifer zones are not free from arsenic contamination rather it isthe mode of abstraction that makes the difference. The very shallow tube well tappingthe dug well zone aquifer has also been found to yield arsenic contaminated water.There are places where the number of arsenic yielding tube wells are more in numberbut the degree of arsenic concentration is comparatively less and vice versa.Physical manifestation of the arsenic diseases among the affected population does notalways reflect the degree of concentration of arsenic in the affected area. Arsenicaffected persons may be less in number in places where the degree of concentration isgreater and the number of arsenic yielding tube wells are more in number andviceversa. The reason of the disease may be the quality of food consumed by the peopleresiding in the area and/or the presence of ionic in groundwater in which arsenic occurs.The effect of dilution, created by artificial recharge of arsenic free surface water &rainwater onto the shallow arsenic contaminated aquifer, is found to reduce theconcentration of arsenic in the groundwater.The artificially injected dissolved oxygen in contaminated aquifer, as a measure ofin-situ remediation of arsenic, is found to reduce arsenic and iron concentration in theaqueous phase. The arsenic concentration in the vadose zone is observed belowdetection limit (
Mitigation and Remediation Update from West Bengal and Bihar : Studies and Projects Initiated(xvi)The study of mobilization mechanism carried out by CGWB in association with UCL,London, revealed that arsenic is released from solid phase to aqueous phase byreductive dissolution of FeOOH and corresponding oxidation of organic matter. Thisprocess is mainly driven by reduction of natural organic matter buried in sediment orburied peat deposits.4.1.3 Projects Initiated/Implemented as Remedial MeasuresThe source of arsenic in groundwater is of geogenic origin, whose immediate restoringsolution may not be feasible, unless physicochemical process is adequately understood. Thus, thepossible remedial measures have been to find alternate source or to adopt suitable technologicaloptions to ensure supply of potable water in the arsenic affected areas. The schemes adopted asremedial options can broadly be grouped as under:(i)(ii)(iii)(iv)Uses of surface water sources,Exploring and harnessing alternate arsenic free aquifer,Removal of arsenic from groundwater using arsenic treatment plants/filters,Adopting rainwater harvesting/ watershed management practices.4.1.4 Uses of surface water sourcesSupply of surface water from ponds, rivers etc. for drinking purposes through pipenetwork system after suitable purification by conventional method of treatment viz. coagulation,flocculation, rapid sand filtration and disinfections, as an alternate option, have been put intopractice in some places by the State Govt. Horizontal roughing filter with slow sand filter havebeen adopted, in case of supply of pond water. Eight such surface water based schemes in thestate have been operationalized by the State Government in different places, covering populationof 3.85 million in 1266 mouzas with estimated cost of Rs. 1254.2 crores. Out of them the mainfive schemes are: (i) Malda water supply scheme of 75 MLD capacity covering 1.43 millionpopulation; (ii) South 24 Parganas water supply scheme of 145.31 MLD capacity covering2.951 million population; (iii) North 24 Parganas water supply scheme of 34 MLD capacitycovering 0.751million population; (iv) Mahyampur water supply scheme in Murshidabad districtfor 3.95 MLD capacity covering 68,975 populations; and (v)) Balupur water supply scheme inMalda district of 5.23 MLD capacity for 72,883 populations. Photographs of two such schemes,one at Malda, and another at North 24 Paraganas, which are successfully running, are shown inFigs. 4.1 and 4.2, respectively. Needless to mention that all surface water based schemes aresuccessfully running to provide potable water supply to masses covered under the schemes.Large scale implementations of surface water based schemes are constrained by number offactors, namely; (i) technical feasibility, (ii) water availability, (iii) cost factors, etc.62NIH & CGWB
Page 5:
ACKNOWLEDGEMENTThe Government of In
Page 8 and 9:
nearly 33 villages in 4 districts i
Page 10:
(iii) Whether ex-situ removal techn
Page 14 and 15:
6.4 Experiences during Arsenic Remo
Page 16 and 17:
List of FiguresFigure no. Figure ca
Page 18 and 19:
List of TablesTable no. Table Capti
Page 20 and 21:
Mitigation and Remedy of Groundwate
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31: Mitigation and Remedy of Groundwate
Page 102 and 103: 5.2.2 Co-precipitationMitigation an
Page 124 and 125: 5.8 SummaryMitigation and Remedy of
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143:
Page 144 and 145:
Page 146 and 147:
Page 148 and 149:
Page 150 and 151:
Page 152 and 153:
Page 154 and 155:
Page 156 and 157:
Page 158 and 159:
Page 160 and 161:
Page 162 and 163:
Page 164 and 165:
Page 166 and 167:
Page 168 and 169:
Page 170 and 171:
Page 172 and 173:
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Page 180 and 181:
Page 182 and 183:
Page 184 and 185:
Page 186 and 187:
Page 188 and 189:
Page 190 and 191:
Page 192 and 193:
Page 194 and 195:
Page 196 and 197:
Page 198 and 199:
Page 200 and 201:
Page 202 and 203:
show all

Mitigation and Remedy of Groundwater Arsenic Menace in India

Create successful ePaper yourself

Delete template?

Save as template?