Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India)

The spatial distribution of arsenic (As) concentrations along three classified hydrogeomorphological zones in the Brahmaputra River Valley in Assam (India) have been investigated: zone I, comprising the piedmont and alluvial fans; zone II, comprising the runoff areas; and zone III, comprising the di...

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Main Authors: Choudhury, R., Mahanta, C., Verma, S., Mukherjee, Abhijit
Format: Journal Article
Published: 2017
Online Access:http://hdl.handle.net/20.500.11937/67109
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author Choudhury, R.
Mahanta, C.
Verma, S.
Mukherjee, Abhijit
author_facet Choudhury, R.
Mahanta, C.
Verma, S.
Mukherjee, Abhijit
author_sort Choudhury, R.
building Curtin Institutional Repository
collection Online Access
description The spatial distribution of arsenic (As) concentrations along three classified hydrogeomorphological zones in the Brahmaputra River Valley in Assam (India) have been investigated: zone I, comprising the piedmont and alluvial fans; zone II, comprising the runoff areas; and zone III, comprising the discharge zones. Groundwater (150 samples) from shallow hand-pumped and public water supply wells (2–60 m in depth) was analysed for chemical composition to examine the geochemical processes controlling As mobilization. As concentrations up to 0.134 mg/L were recorded, with concentrations below the World Health Organization and the Bureau of Indian Standards drinking-water limits of 0.01 mg/L being found mainly in the proximal recharge areas. Eh and other redox indicators (i.e., dissolved oxygen, Fe, Mn and As) indicate that, except for samples taken in the recharge zone, groundwater is reducing and exhibits a systematic decrease in redox conditions along the runoff and discharge zones. Hydrogeochemical evaluation indicated that zone I, located along the proximal recharge areas, is characterized by low As concentration, while zones II and III are areas with high and moderate concentrations, respectively. Systematic changes in As concentrations along the three zones support the view that areas of active recharge with high hydraulic gradient are potential areas hosting low-As aquifers.
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spelling curtin-20.500.11937-671092018-10-01T03:46:12Z Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India) Choudhury, R. Mahanta, C. Verma, S. Mukherjee, Abhijit The spatial distribution of arsenic (As) concentrations along three classified hydrogeomorphological zones in the Brahmaputra River Valley in Assam (India) have been investigated: zone I, comprising the piedmont and alluvial fans; zone II, comprising the runoff areas; and zone III, comprising the discharge zones. Groundwater (150 samples) from shallow hand-pumped and public water supply wells (2–60 m in depth) was analysed for chemical composition to examine the geochemical processes controlling As mobilization. As concentrations up to 0.134 mg/L were recorded, with concentrations below the World Health Organization and the Bureau of Indian Standards drinking-water limits of 0.01 mg/L being found mainly in the proximal recharge areas. Eh and other redox indicators (i.e., dissolved oxygen, Fe, Mn and As) indicate that, except for samples taken in the recharge zone, groundwater is reducing and exhibits a systematic decrease in redox conditions along the runoff and discharge zones. Hydrogeochemical evaluation indicated that zone I, located along the proximal recharge areas, is characterized by low As concentration, while zones II and III are areas with high and moderate concentrations, respectively. Systematic changes in As concentrations along the three zones support the view that areas of active recharge with high hydraulic gradient are potential areas hosting low-As aquifers. 2017 Journal Article http://hdl.handle.net/20.500.11937/67109 10.1007/s10040-017-1584-2 restricted
spellingShingle Choudhury, R.
Mahanta, C.
Verma, S.
Mukherjee, Abhijit
Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India)
title Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India)
title_full Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India)
title_fullStr Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India)
title_full_unstemmed Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India)
title_short Arsenic distribution along different hydrogeomorphic zones in parts of the Brahmaputra River Valley, Assam (India)
title_sort arsenic distribution along different hydrogeomorphic zones in parts of the brahmaputra river valley, assam (india)
url http://hdl.handle.net/20.500.11937/67109