Groundwater arsenic contamination affecting different geologic domains in India—a review: influence of geological setting, fluvial geomorphology and Quaternary stratigraphy

Abstract

Arsenic contamination in groundwater is pervasive within lowland organic-rich Bengal Delta and narrow entrenched channels in the Middle Ganga floodplains. Local areas of Damodar fan-delta and isolated areas within the Dongargarh Proterozoic rift-zone in central India are also contaminated. In this rift-zone, arsenic is enriched in felsic magmatic rocks and weathered rocks and soils from local areas are enriched further in arsenic and iron. Late Quaternary stratigraphy, geomorphology and sedimentation have influenced groundwater arsenic contamination in alluvium that aggraded during the Holocene sea-level rise. No specific source of arsenic could be identified, although Himalaya is the main provenance for the Ganga floodplain and the Bengal Delta. Gondwana coal seams and other Peninsular Indian rocks might be sources for arsenic in the Damodar fan-delta. As-bearing pyrite or any As-mineral is nearly absent in the aquifer sediments. Arsenic mainly occurs adsorbed on hydrated-iron-oxide (HFO), which coat sediment grains and minerals. Arsenic and iron are released to groundwater by bio-mediated reductive dissolution of HFO with corresponding oxidation of organic matter.

Arsenic Contamination in Groundwater in the Middle Gangetic Plain, India: Its Relations to Fluvial Geomorphology and Quaternary Stratigraphy

“…However, the same mineralogical assemblage is also reported from borehole sediments in Jessore district of Bangladesh and Nadia district of West Bengal (Akai et al 2004 ;Acharyya and Shah 2007 ). Arsenic and iron concentrations in suspended river sediments were found in signifi cant amount in the suspended river sediments of the Yamuna, Ganga, Gomati, Ghaghara, Sone, Gondak, Buri Gandak and Kosi rivers (Shah 2014 ).…”

“…High groundwater As concentration is found in the Holocene aquifers, while the Pleistocene aquifers have a low As level. Occurrences of high groundwater As are signifi cantly linked with the Pleistocene and Holocene aquifers in the Mekong Delta, Red River Delta and Bengal Basin (Acharyya et al 2000 ;Kinniburgh and Smedley 2001 ;Berg et al 2001 ;Acharyya and Shah 2007 ;von Brömssen et al 2007 ;Shamsudduha et al 2008 ;Polizzotto et al 2008 ;Winkel et al 2008 ).…”

Ground Water Arsenic Contamination and Its Health Effects in Bangladesh

“…Along with sediments from those areas many weathered minerals including arsenic had entered the basin and had been deposited in the delta over thousands of years. The high arsenic content areas are found in the catchments of the Ganges, Brahmaputra, and Meghna rivers [22][23][24][25][26][27][28][29][30][31].…”

Utilisation of satellite data in identification of geomorphic landform and its role in arsenic release in groundwater

“…There are several hypotheses regarding the enhanced concentration of arsenic in groundwater but the most accepted hypothesis is reductive dissolution of iron hydroxide (FeOOH), which release the adsorbed arsenic in the aquatic environment (Bhattacharya et al, 2006;McArthur et al, 2004). However identification of source of arsenic is still a matter of study, but some researchers have identified the Himalayan rock as a primary source of arsenic which comes along the river and get deposited in plain areas (Acharyya and Shah, 2007;McArthur et al, 2001). The arsenic enriched groundwater is mainly restricted to the Holocene aquifer at shallow and intermediate depth (Ahmed et al, 2001;Mukherjee and Bhattacharya, 2001).…”