1
|
Sarkar A, Paul B, Darbha GK. The groundwater arsenic contamination in the Bengal Basin-A review in brief. CHEMOSPHERE 2022; 299:134369. [PMID: 35318018 DOI: 10.1016/j.chemosphere.2022.134369] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 03/12/2022] [Accepted: 03/16/2022] [Indexed: 05/27/2023]
Abstract
The presence of arsenic in the groundwater of the densely-populated Bengal Basin evolved as a mass-poisoning agent and is a reason for the misery of millions of people living here. High-level arsenic was detected in the shallow aquifer-tube wells of the basin in the late-20th century. The redox conditions and the biogeochemical activities in the shallow aquifers support the existence of arsenic in its most toxic +3 state. The shallow aquifers are constructed by the Holocene reduced grey sands, having a lesser capacity to hold the arsenic brought from the Himalayas by the Ganga-Brahmaputra-Meghna river system. Among several other hypotheses, the reductive dissolution of arsenic bearing Fe-oxyhydroxides coupled with the microbial activities in the organic-matter-rich Holocene grey sands is believed to be the primary reason for releasing arsenic in groundwater of basinal shallow aquifers. The deep aquifers below the late Pleistocene aquifers and the Palaeo-interfluvial aquifers capped by the last glacial maximum Palaeosol generally contain arsenic-free or low-arsenic water. Ingress of arsenic into the deep aquifers from the shallow aquifers was considered to have been caused by extensive non-domestic pumping. However, studies have found that extensive pumping is unlikely to contaminate the deep aquifer water with higher levels of arsenic within decadal time scales. Irrigation-pumping may produce hydraulic barriers between the shallow and deep aquifer-groundwater and distributes arsenic in the topsoil by flushing. Significant disparities have been observed among the Bengal basinal groundwater arsenic concentrations. However, abrupt spatial variation in groundwater arsenic concentrations has been a key feature of the basin.
Collapse
Affiliation(s)
- Arpan Sarkar
- Department of Environmental Science & Engineering, Indian Institute of Technology (ISM) Dhanbad, Dhanbad, Jharkhand, 826004, India.
| | - Biswajit Paul
- Department of Environmental Science & Engineering, Indian Institute of Technology (ISM) Dhanbad, Dhanbad, Jharkhand, 826004, India.
| | - Gopala Krishna Darbha
- Environmental Nanoscience Laboratory, Department of Earth Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India; Centre for Climate and Environmental Studies, Indian Institute of Science Education and Research Kolkata, Mohanpur, Nadia, West Bengal, 741246, India.
| |
Collapse
|
2
|
Mozumder MRH, Bostick BC, Selim M, Islam MA, Shoenfelt EM, Ellis T, Mailloux BJ, Choudhury I, Ahmed KM, van Geen A. Similar retardation of arsenic in gray Holocene and orange Pleistocene sediments: Evidence from field-based column experiments in Bangladesh. WATER RESEARCH 2020; 183:116081. [PMID: 32784107 DOI: 10.1016/j.watres.2020.116081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 06/11/2023]
Abstract
Groundwater flow has the potential to introduce arsenic (As) in previously uncontaminated aquifers. The extent to which As transport is retarded by adsorption is particularly relevant in Bangladesh where low-As wells offer the best chance of reducing chronic exposure to As of a large rural population dependent on groundwater. In this study, column experiments were conducted with intact cores in the field to measure As retardation. Freshly collected cores of reduced iron (Fe-II) dominated gray sediment of Holocene age as well as oxidized Fe (III)-coated orange sediment of Pleistocene age were eluted at pore-water velocities of 40-230 cm/day with anoxic groundwater pumped directly from a well and containing 320 μg/L As. Up to 100 μg/L As was immediately released from gray sand but the main As breakthrough for both gray and orange sand occurred between 30 and 70 pore volumes, depending on flow rate. The early release of As from gray sand is attributed to the presence of a weakly bound pool of As. The sorption of As was kinetically limited in both gray and orange sand columns. We used a reversible multi-reaction transport model to simulate As breakthrough curves while keeping the model parameters as constant as possible. Contrary to the notion that dissolved As is sorbed more strongly to orange sands, we show that As was similarly retarded in both gray and orange sands in the field.
Collapse
Affiliation(s)
- M Rajib H Mozumder
- Lamont-Doherty Earth Observatory of Columbia University, NY, 10964, USA; Now at Gradient, One Beacon Street, 17th Floor, Boston, MA, 02108, USA.
| | | | - Magdi Selim
- School of Plant, Environmental, and Soil Sciences, Louisiana State University AgCenter, Baton Rouge, LA, 70803, USA
| | - M Atikul Islam
- Department of Geology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Elizabeth M Shoenfelt
- Lamont-Doherty Earth Observatory of Columbia University, NY, 10964, USA; Now at Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Tyler Ellis
- Lamont-Doherty Earth Observatory of Columbia University, NY, 10964, USA
| | - Brian J Mailloux
- Environmental Science, Barnard College, New York, NY, 10027, USA
| | - Imtiaz Choudhury
- Department of Geology, University of Dhaka, Dhaka, 1000, Bangladesh
| | - Kazi M Ahmed
- Department of Geology, University of Dhaka, Dhaka, 1000, Bangladesh
| | | |
Collapse
|
3
|
Mozumder MRH, Michael HA, Mihajlov I, Khan MR, Knappett PSK, Bostick BC, Mailloux BJ, Ahmed KM, Choudhury I, Koffman T, Ellis T, Whaley-Martin K, San Pedro R, Slater G, Stute M, Schlosser P, van Geen A. Origin of Groundwater Arsenic in a Rural Pleistocene Aquifer in Bangladesh Depressurized by Distal Municipal Pumping. WATER RESOURCES RESEARCH 2020; 56:e2020WR027178. [PMID: 33958831 PMCID: PMC8099038 DOI: 10.1029/2020wr027178] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2020] [Accepted: 04/30/2020] [Indexed: 05/26/2023]
Abstract
Across South Asia, millions of villagers have reduced their exposure to high-arsenic (As) groundwater by switching to low-As wells. Isotopic tracers and flow modeling are used in this study to understand the groundwater flow system of a semi-confined aquifer of Pleistocene (>10 kyr) age in Bangladesh that is generally low in As but has been perturbed by massive pumping at a distance of about 25 km for the municipal water supply of Dhaka. A 10- to 15-m-thick clay aquitard caps much of the intermediate aquifer (>40- to 90-m depth) in the 3-km2 study area, with some interruptions by younger channel sand deposits indicative of river scouring. Hydraulic heads in the intermediate aquifer below the clay-capped areas are 1-2 m lower than in the high-As shallow aquifer above the clay layer. In contrast, similar heads in the shallow and intermediate aquifer are observed where the clay layer is missing. The head distribution suggests a pattern of downward flow through interruptions in the aquitard and lateral advection from the sandy areas to the confined portion of the aquifer. The interpreted flow system is consistent with 3H-3He ages, stable isotope data, and groundwater flow modeling. Lateral flow could explain an association of elevated As with high methane concentrations within layers of gray sand below certain clay-capped portions of the Pleistocene aquifer. An influx of dissolved organic carbon from the clay layer itself leading to a reduction of initially orange sands has also likely contributed to the rise of As.
Collapse
Affiliation(s)
- M. R. H. Mozumder
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
- Now at Gradient, Boston, MA, USA
| | - H. A. Michael
- Department of Earth Sciences, University of Delaware, Newark, DE, USA
| | - I. Mihajlov
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
- Now at Geosyntec Consultants, Huntington Beach, CA, USA
| | - M. R. Khan
- Department of Geology, University of Dhaka, Dhaka, Bangladesh
| | - P. S. K. Knappett
- Geology & Geophysics, Texas A&M University, College Station, TX, USA
| | - B. C. Bostick
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - B. J. Mailloux
- Environmental Science, Barnard College, New York, NY, USA
| | - K. M. Ahmed
- Department of Geology, University of Dhaka, Dhaka, Bangladesh
| | - I. Choudhury
- Department of Geology, University of Dhaka, Dhaka, Bangladesh
| | - T. Koffman
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
- Now at Land Resources and Environmental Sciences, Montana State University, Bozeman, MT, USA
| | - T. Ellis
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| | - K. Whaley-Martin
- Earth and Environmental Sciences, McMaster University, Hamilton, Ontario, Canada
- Now at Civil and Mineral Engineering Department, University of Toronto, Ontario, Canada
| | - R. San Pedro
- Earth and Environmental Sciences, McMaster University, Hamilton, Ontario, Canada
| | - G. Slater
- Earth and Environmental Sciences, McMaster University, Hamilton, Ontario, Canada
| | - M. Stute
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
- Environmental Science, Barnard College, New York, NY, USA
| | - P. Schlosser
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
- Now at Julie Ann Wrigley Global Institute of Sustainability, Arizona State University, Tempe, AZ, USA
| | - A. van Geen
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, USA
| |
Collapse
|
4
|
Mihajlov I, Mozumder MRH, Bostick BC, Stute M, Mailloux BJ, Knappett PSK, Choudhury I, Ahmed KM, Schlosser P, van Geen A. Arsenic contamination of Bangladesh aquifers exacerbated by clay layers. Nat Commun 2020; 11:2244. [PMID: 32382006 PMCID: PMC7205959 DOI: 10.1038/s41467-020-16104-z] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 04/08/2020] [Indexed: 12/31/2022] Open
Abstract
Confining clay layers typically protect groundwater aquifers against downward intrusion of contaminants. In the context of groundwater arsenic in Bangladesh, we challenge this notion here by showing that organic carbon drawn from a clay layer into a low-arsenic pre-Holocene (>12 kyr-old) aquifer promotes the reductive dissolution of iron oxides and the release of arsenic. The finding explains a steady rise in arsenic concentrations in a pre-Holocene aquifer below such a clay layer and the repeated failure of a structurally sound community well. Tritium measurements indicate that groundwater from the affected depth interval (40–50 m) was recharged >60 years ago. Deeper (55–65 m) groundwater in the same pre-Holocene aquifer was recharged only 10–50 years ago but is still low in arsenic. Proximity to a confining clay layer that expels organic carbon as an indirect response to groundwater pumping, rather than directly accelerated recharge, caused arsenic contamination of this pre-Holocene aquifer. Generally it is thought that confining clay layers provide protection to low-arsenic groundwaters against intrusion of shallower, high-arsenic groundwater bodies. Here, the authors show that impermeable clay layers can increase arsenic input to underlying groundwater systems due to reduction of iron oxides coupled to carbon oxidation.
Collapse
Affiliation(s)
- Ivan Mihajlov
- Department of Earth and Environmental Sciences, Columbia University, New York, NY, 10025, USA.,Geosyntec Consultants, Huntington Beach, CA, 92648, USA
| | - M Rajib H Mozumder
- Department of Earth and Environmental Sciences, Columbia University, New York, NY, 10025, USA.,Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA.,Gradient, Cambridge, MA, 02138, USA
| | - Benjamín C Bostick
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA
| | - Martin Stute
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA.,Environmental Sciences, Barnard College, New York, NY, 10025, USA
| | - Brian J Mailloux
- Environmental Sciences, Barnard College, New York, NY, 10025, USA
| | - Peter S K Knappett
- Department of Geology & Geophysics, Texas A&M University, College Station, TX, 77843, USA
| | | | | | - Peter Schlosser
- Department of Earth and Environmental Sciences, Columbia University, New York, NY, 10025, USA.,Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA.,School of Sustainability, Arizona State University, Tempe, AZ, 85281, USA
| | - Alexander van Geen
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY, 10964, USA.
| |
Collapse
|
5
|
Jamil N, Feng H, Ahmed KM, Choudhury I, Barnwal P, van Geen A. Effectiveness of Different Approaches to Arsenic Mitigation over 18 Years in Araihazar, Bangladesh: Implications for National Policy. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:5596-5604. [PMID: 31033281 PMCID: PMC6535723 DOI: 10.1021/acs.est.9b01375] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
About 20 million rural Bangladeshis continue to drink well water containing >50 μg/L arsenic (As). This analysis argues for reprioritizing interventions on the basis of a survey of wells serving a population of 380,000 conducted one decade after a previous round of testing overseen by the government. The available data indicate that testing alone reduced the exposed population in the area in the short term by about 130,000 by identifying the subset of low As wells that could be shared at a total cost of <US$1 per person whose exposure was reduced. Testing also had a longer term impact, as 60,000 exposed inhabitants lowered their exposure by installing new wells to tap intermediate (45-90 m) aquifers that are low in As at their own expense of US$30 per person whose exposure was reduced. In contrast, the installation of over 900 deep (>150 m) wells and a single piped-water supply system by the government reduced exposure of little more than 7000 inhabitants at a cost of US$150 per person whose exposure was reduced. The findings make a strong case for long-term funding of free well testing on a massive scale with piped water or groundwater treatment only as a last resort.
Collapse
Affiliation(s)
- Nadia
B. Jamil
- Department
of Earth and Environmental Studies, Montclair
State University, Montclair, New Jersey, United States
| | - Huan Feng
- Department
of Earth and Environmental Studies, Montclair
State University, Montclair, New Jersey, United States
| | | | | | - Prabhat Barnwal
- Department
of Economics, Michigan State University, East Lansing, Michigan, United States
| | - Alexander van Geen
- Lamont-Doherty
Earth Observatory, Columbia University, Palisades, New York, United States
- Phone: 845 365 8644; e-mail:
| |
Collapse
|
6
|
Seasonal Variation of Water Quality in Unregulated Domestic Wells. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2019; 16:ijerph16091569. [PMID: 31060292 PMCID: PMC6539867 DOI: 10.3390/ijerph16091569] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 04/30/2019] [Accepted: 05/01/2019] [Indexed: 12/01/2022]
Abstract
In the United States (U.S.), up to 14% of the population depend on private wells as their primary drinking water source. The U.S. government does not regulate contaminants in private wells. The goals of this study were to investigate the quality of drinking water from unregulated private wells within one mile (1.6 kilometers) of an effluent-dominated river in the arid Southwest, determine differences in contaminant levels between wet and dry seasons, and identify contributions from human sources by specifically measuring man-made organic contaminants (perfluorooctanoic acid (PFOA), perfluorooctane sulfate (PFOS), and sucralose). Samples were collected during two dry seasons and two wet seasons over the course of two years and analyzed for microbial (Escherichia coli), inorganic (arsenic, cadmium, chromium, copper, lead, mercury, nitrate), and synthetic organic (PFOA, PFOS, and sucralose) contaminants. Arsenic, nitrate, and Escherichia coli concentrations exceeded their respective regulatory levels of 0.01 mg/L, 10 mg/L, and 1 colony forming unit (CFU)/100 mL, respectively. The measured concentrations of PFOA and PFOS exceeded the respective Public Health Advisory level. Arsenic, PFOA, PFOS, and sucralose were significantly higher during the dry seasons, whereas E. coli was higher during the wet seasons. While some contaminants were correlated (e.g., As and Hg ρ = 0.87; PFOA and PFOS ρ = 0.45), the lack of correlation between different contaminant types indicates that they may arise from different sources. Multi-faceted interventions are needed to reduce exposure to drinking water above health-based guidelines.
Collapse
|
7
|
Berberich J, Li T, Sahle-Demessie E. Biosensors for Monitoring Water Pollutants: A Case Study With Arsenic in Groundwater. SEP SCI TECHNOL 2019. [DOI: 10.1016/b978-0-12-815730-5.00011-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
8
|
McArthur JM, Sikdar PK, Leng MJ, Ghosal U, Sen I. Groundwater Quality beneath an Asian Megacity on a Delta: Kolkata's (Calcutta's) Disappearing Arsenic and Present Manganese. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:5161-5172. [PMID: 29676565 DOI: 10.1021/acs.est.7b04996] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Kolkata, the capital city of West Bengal, exploits groundwater for public water-supply. The groundwater has been reported to be widely polluted by arsenic (As). Analysis for As in 280 groundwaters from across Kolkata, failed to detect As concentrations >10 μg/L from natural processes. Arsenic concentrations between 10 and 79 μg/L found in 14 of the 280 groundwaters are remnant from a pollution-plume emanating from a single factory site where Paris Green, an arsenical pesticide, was manufactured between 1965 and 1985. In 45% of groundwaters sampled, concentrations of Mn exceed 0.4 mg/L, a putative health guideline value for drinking water. Sporadic minor hazards are posed by Pb > 10 μg/L introduced into groundwater from well-fittings, from 4% of groundwaters with F concentrations between 0.75 and 1 mg/L, and the 14% of groundwaters containing more than 500 mg/L Na, concentrations that might contribute to excessive daily intake of Na. Compounding hazards from As, F, Mn, Na, and Pb, shows that 64% of public wells and 40% of municipal wells supply groundwater of suspect quality. Groundwaters comply with WHO Guideline Values for drinking water in terms of Cr, Cu, Co, NO2, NO3, Sb, Se, and U. Aesthetic guideline values for Fe, Mn, SO4, and Cl are exceeded for many groundwaters.
Collapse
Affiliation(s)
- J M McArthur
- Earth Sciences , University College London , Gower Street , London WC1E 6BT , United Kingdom
| | - P K Sikdar
- Department of Environment Management , Indian Institute of Social Welfare and Business Management , Management House, College Square (West) , Kolkata 700 073 , India
| | - M J Leng
- NERC Isotope Geosciences Laboratory , British Geological Survey , Keyworth , Nottingham NG12 5GG , United Kingdom
- Centre for Environmental Geochemistry, School of Biosciences, Sutton Bonington Campus , University of Nottingham , Loughborough LE12 5RD , United Kingdom
| | - U Ghosal
- Department of Environment Management , Indian Institute of Social Welfare and Business Management , Management House, College Square (West) , Kolkata 700 073 , India
| | - I Sen
- Department of Environment Management , Indian Institute of Social Welfare and Business Management , Management House, College Square (West) , Kolkata 700 073 , India
| |
Collapse
|
9
|
Mihajlov I, Stute M, Schlosser P, Mailloux BJ, Zheng Y, Choudhury I, Ahmed K, van Geen A. Recharge of low-arsenic aquifers tapped by community wells in Araihazar, Bangladesh, inferred from environmental isotopes. WATER RESOURCES RESEARCH 2016; 52:3324-3349. [PMID: 28966406 PMCID: PMC5617127 DOI: 10.1002/2015wr018224] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
More than 100,000 community wells have been installed in the 150-300 m depth range throughout Bangladesh over the past decade to provide low-arsenic drinking water (<10 μg/L As), but little is known about how aquifers tapped by these wells are recharged. Within a 25 km2 area of Bangladesh east of Dhaka, groundwater from 65 low-As wells in the 35-240 m depth range was sampled for tritium (3H), oxygen and hydrogen isotopes of water (18O/16O and 2H/1H), carbon isotope ratios in dissolved inorganic carbon (DIC, 14C/12C and 13C/12C), noble gases, and a suite of dissolved constituents, including major cations, anions, and trace elements. At shallow depths (<90 m), 24 out of 42 wells contain detectable 3H of up to 6 TU, indicating the presence of groundwater recharged within 60 years. Radiocarbon (14C) ages in DIC range from modern to 10 kyr. In the 90-240 m depth range, however, only 5 wells shallower than 150 m contain detectable 3H (<0.3 TU) and 14C ages of DIC cluster around 10 kyr. The radiogenic helium (4He) content in groundwater increases linearly across the entire range of 14C ages at a rate of 2.5×10-12 ccSTP 4He g-1 yr-1. Within the samples from depths >90 m, systematic relationships between 18O/16O, 2H/1H, 13C/12C and 14C/12C, and variations in noble gas temperatures, suggest that changes in monsoon intensity and vegetation cover occurred at the onset of the Holocene, when the sampled water was recharged. Thus, the deeper low-As aquifers remain relatively isolated from the shallow, high-As aquifer.
Collapse
Affiliation(s)
- I. Mihajlov
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY
10964, USA
- Department of Earth and Environmental Sciences, Columbia University, New
York, NY 10027, USA
| | - M. Stute
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY
10964, USA
- Barnard College, New York, NY 10027, USA
| | - P. Schlosser
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY
10964, USA
- Department of Earth and Environmental Sciences, Columbia University, New
York, NY 10027, USA
- Department of Earth and Environmental Engineering, Columbia University, New
York, NY 10027, USA
| | | | - Y. Zheng
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY
10964, USA
- Queens College, City University of New York, New York, NY 11367, USA
| | - I. Choudhury
- Department of Geology, Dhaka University, Dhaka 1000, Bangladesh
| | - K.M. Ahmed
- Department of Geology, Dhaka University, Dhaka 1000, Bangladesh
| | - A. van Geen
- Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY
10964, USA
| |
Collapse
|