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Amorosi A, Sammartino I. Predicting natural arsenic enrichment in peat-bearing, alluvial and coastal depositional systems: A generalized model based on sequence stratigraphy. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 924:171571. [PMID: 38492587 DOI: 10.1016/j.scitotenv.2024.171571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 02/23/2024] [Accepted: 03/06/2024] [Indexed: 03/18/2024]
Abstract
Hazardously high concentrations of arsenic exceeding the threshold limits for soils and drinking waters have been widely reported from Quaternary sedimentary successions and shallow aquifers of alluvial and coastal lowlands worldwide, raising public health concerns due to potential human exposure to arsenic. A combined sedimentological and geochemical analysis of subsurface deposits, 2.5-50 m deep, from the SE Po Plain (Italy) documents a systematic tendency for naturally-occurring arsenic to accumulate in peat-rich layers, with concentrations invariably greater than maximum permissible levels. A total of 366 bulk sediment samples from 40 cores that penetrated peat-bearing deposits were analysed by X-ray fluorescence. Arsenic concentrations associated with 7 peat-free lithofacies associations (fluvial-channel, levee/crevasse, floodplain, swamp, lagoon/bay, beach-barrier, and offshore/prodelta) exhibit background values invariably below threshold levels (<20 mg/kg). In contrast, total arsenic contents from peaty clay and peat showed 2-6 times larger As accumulation. A total of 204 near-surface (0-2.5 m) samples from modern alluvial and coastal depositional environments exhibit the same trends as their deeper counterparts, total arsenic peaking at peat horizons above the threshold values for contaminated soils. The arsenic-bearing, peat-rich Quaternary successions of the Po Plain accumulated under persisting reducing conditions in wetlands of backstepping estuarine and prograding deltaic depositional environments during the Early-Middle Holocene sea-level rise and subsequent stillstand. Contamination of the Holocene and underlying Pleistocene aquifer systems likely occurred through the release of As by microbially-mediated reductive dissolution. Using high-resolution sequence-stratigraphic concepts, we document that the Late Pleistocene-Holocene lithofacies architecture dictates the subsurface distribution of As. The "wetland trajectory", i.e. the path taken by the landward/seaward shift of peat-rich depositional environments during the Holocene, may help predict spatial patterns of natural As distribution, delineating the highest As-hazard zones and providing a realistic view of aquifer contamination even in unknown areas.
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Affiliation(s)
- Alessandro Amorosi
- Department of Biological, Geological and Environmental Sciences (BiGeA), University of Bologna, Via Zamboni 67, 40126 Bologna, Italy.
| | - Irene Sammartino
- National Research Council (CNR), Institute of Marine Science (ISMAR), Via Gobetti 101, 40129 Bologna, Italy.
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Nawrin N, Arnaud E, Priebe E. Geospatial analysis of groundwater arsenic and fluoride in Quaternary aquifers of southern Ontario, Canada. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 923:171485. [PMID: 38447736 DOI: 10.1016/j.scitotenv.2024.171485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 02/23/2024] [Accepted: 03/03/2024] [Indexed: 03/08/2024]
Abstract
The geological setting of an area plays a critical role in the transfer and ultimate distribution of hydrochemical constituents present in groundwater. In southern Ontario, Canada, the present physiography was significantly influenced by glacial processes during the Quaternary period. The heterogeneous nature and complex pattern of shallow subsurface glacial overburden sediments, likely affect the fate of different groundwater constituents. In this study, arsenic (As) and fluoride (F-) concentrations from 515 water wells, that are constructed within overburden sediment, were analyzed with the physiographic map of southern Ontario along with other related variables. Geospatial mapping and several spatial statistical analyses were performed to examine the possible geological influence on As and F- distribution and water-well susceptibility at a regional scale. Key findings suggest four physiographic settings were significant variables influencing the distribution of As and F- in differently constructed bored/dug and drilled wells. Bored/dug wells in Bevelled Till Plains and bored/dug wells in Undrumlinized and Bevelled Till Plains were found to be relatively susceptible to As and F- contamination respectively. In contrast, bored/dug and drilled wells in Drumlinized Till Plains and Drumlins and drilled wells in Sand Plains seemed to be relatively safe from F- and As respectively. The statistical regression analyses suggested that other variables, such as the application of phosphate fertilizer and the textures of till, influenced the spatial distribution of As and F- as well as which types of wells (bored/dug or drilled) were impacted. The geospatial mapping and statistical cluster analysis indicated that the possible sources of elevated As and F- in drilled wells are the clasts of underlying bedrock. The relationship between physiographic settings and impacted overburden wells in southern Ontario provides planners with an approach to water-well susceptibility assessments at the regional scale, which in turn can guide further local analysis for water resource management.
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Affiliation(s)
- Nazia Nawrin
- School of Environmental Sciences and Morwick G360 Groundwater Research Institute, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada.
| | - Emmanuelle Arnaud
- School of Environmental Sciences and Morwick G360 Groundwater Research Institute, University of Guelph, 50 Stone Road East, Guelph, Ontario N1G 2W1, Canada
| | - Elizabeth Priebe
- Canadian Nuclear Laboratories, 286 Plant Rd, Chalk River, Ontario K0J 1J0, Canada
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3
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Raff JL, Goodbred SL, Pickering JL, Sincavage RS, Ayers JC, Hossain MS, Wilson CA, Paola C, Steckler MS, Mondal DR, Grimaud JL, Grall CJ, Rogers KG, Ahmed KM, Akhter SH, Carlson BN, Chamberlain EL, Dejter M, Gilligan JM, Hale RP, Khan MR, Muktadir MG, Rahman MM, Williams LA. Sediment delivery to sustain the Ganges-Brahmaputra delta under climate change and anthropogenic impacts. Nat Commun 2023; 14:2429. [PMID: 37105978 PMCID: PMC10140268 DOI: 10.1038/s41467-023-38057-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
The principal nature-based solution for offsetting relative sea-level rise in the Ganges-Brahmaputra delta is the unabated delivery, dispersal, and deposition of the rivers' ~1 billion-tonne annual sediment load. Recent hydrological transport modeling suggests that strengthening monsoon precipitation in the 21st century could increase this sediment delivery 34-60%; yet other studies demonstrate that sediment could decline 15-80% if planned dams and river diversions are fully implemented. We validate these modeled ranges by developing a comprehensive field-based sediment budget that quantifies the supply of Ganges-Brahmaputra river sediment under varying Holocene climate conditions. Our data reveal natural responses in sediment supply comparable to previously modeled results and suggest that increased sediment delivery may be capable of offsetting accelerated sea-level rise. This prospect for a naturally sustained Ganges-Brahmaputra delta presents possibilities beyond the dystopian future often posed for this system, but the implementation of currently proposed dams and diversions would preclude such opportunities.
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Affiliation(s)
- Jessica L Raff
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA.
| | - Steven L Goodbred
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA.
| | - Jennifer L Pickering
- Center for Applied Earth Science and Engineering Research, The University of Memphis, Memphis, TN, USA
| | | | - John C Ayers
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA
| | - Md Saddam Hossain
- Center for Applied Earth Science and Engineering Research, The University of Memphis, Memphis, TN, USA
| | - Carol A Wilson
- Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA, USA
| | - Chris Paola
- Department of Earth and Environmental Sciences, St Anthony Falls Laboratory, University of Minnesota, Minneapolis, MN, USA
| | - Michael S Steckler
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
| | - Dhiman R Mondal
- Haystack Observatory, Massachusetts Institute of Technology, Westford, MA, USA
| | - Jean-Louis Grimaud
- Centre de Géosciences, PSL University/ MINES Paris, Fontainebleau, France
| | - Celine Jo Grall
- Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, USA
- CNRS - Littoral Environnement et Sociétés, La Rochelle University, La Rochelle, France
| | - Kimberly G Rogers
- Institute for Arctic and Alpine Research, University of Colorado, Boulder, CO, USA
| | | | | | - Brandee N Carlson
- Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX, USA
| | | | - Meagan Dejter
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA
| | - Jonathan M Gilligan
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA
| | - Richard P Hale
- Department of Ocean & Earth Sciences, Old Dominion University, Norfolk, VA, USA
| | - Mahfuzur R Khan
- Department of Geology, University of Dhaka, Dhaka, Bangladesh
| | - Md Golam Muktadir
- Department of Environmental Science, Bangladesh University of Professionals, Dhaka, Bangladesh
| | - Md Munsur Rahman
- Institute of Water and Flood Management, Bangladesh University of Engineering and Technology, Dhaka, Bangladesh
| | - Lauren A Williams
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, TN, USA
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Podgorski J, Araya D, Berg M. Geogenic manganese and iron in groundwater of Southeast Asia and Bangladesh - Machine learning spatial prediction modeling and comparison with arsenic. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 833:155131. [PMID: 35405246 DOI: 10.1016/j.scitotenv.2022.155131] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 03/25/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Naturally occurring, geogenic manganese (Mn) and iron (Fe) are frequently found dissolved in groundwater at concentrations that make the water difficult to use (deposits, unpleasant taste) or, in the case of Mn, a potential health hazard. Over 6000 groundwater measurements of Mn and Fe in Southeast Asia and Bangladesh were assembled and statistically examined with other physicochemical parameters. The machine learning methods random forest and generalized boosted regression modeling were used with spatially continuous environmental parameters (climate, geology, soil, topography) to model and map the probability of groundwater Mn > 400 μg/L and Fe > 0.3 mg/L for Southeast Asia and Bangladesh. The modeling indicated that drier climatic conditions are associated with a tendency of elevated Mn concentrations, whereas high Fe concentrations tend to be found in a more humid climate with elevated levels of soil organic carbon. The spatial distribution of Mn > 400 μg/L and Fe > 0.3 mg/L was compared and contrasted with that of the critical geogenic contaminant arsenic (As), confirming that high Fe concentrations are often associated with high As concentrations, whereas areas of high concentrations of Mn and As are frequently found adjacent to each other. The probability maps draw attention to areas prone to elevated concentrations of geogenic Mn and Fe in groundwater and can help direct efforts to mitigate their negative effects. The greatest Mn hazard is found in densely populated northwest Bangladesh and the Mekong, Red and Ma River Deltas of Cambodia and Vietnam. Widespread elevated Fe concentrations and their associated negative effects on water infrastructure pose challenges to water supply. The Mn and Fe prediction maps demonstrate the value of machine learning for the geospatial prediction modeling and mapping of groundwater contaminants as well as the potential for further constituents to be targeted by this novel approach.
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Affiliation(s)
- Joel Podgorski
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Water Resources and Drinking Water, 8600 Dübendorf, Switzerland.
| | - Dahyann Araya
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Water Resources and Drinking Water, 8600 Dübendorf, Switzerland
| | - Michael Berg
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, Department Water Resources and Drinking Water, 8600 Dübendorf, Switzerland
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Bindal S, Singh CK. Predicting groundwater arsenic contamination: Regions at risk in highest populated state of India. WATER RESEARCH 2019; 159:65-76. [PMID: 31078753 DOI: 10.1016/j.watres.2019.04.054] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/20/2019] [Accepted: 04/28/2019] [Indexed: 05/27/2023]
Abstract
Arsenic (As) contamination of groundwater is a public health concern, impacting the lives of approximately 100 million people in India. Chronic exposure to As significantly increases mortality due to the occurrence of several types of cancer, respiratory and cardiac diseases. Uttar Pradesh is a part of the middle Indo-Gangetic plains and has been found to be severely affected by As contamination of groundwater, as established by several small-scale studies. The current study incorporates a hybrid method based on a random forest ensemble algorithm and univariate feature selection using 1473 data points for predicting As in the region. Twenty direct/proxy predictor variables were considered to describe the geochemical environment, aquifer conditions and topography that are responsible for As enrichment in groundwater. The map of As predicted through the hybrid random forest ensemble model shows an overall accuracy of 84.67%. The hybrid random forest model performs better than the univariate, logistic, fuzzy, adaptive fuzzy and adaptive neuro fuzzy inference systems, which have been widely used for As prediction. The projected number of rural populations at risk due to high As exposure is 12% of the total population of the region, which accounts for 23.48 million people who are at risk. The predictive map provides insight for the regions where future testing campaigns and interventions for mitigation should be prioritized by policymakers.
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Affiliation(s)
- Sonal Bindal
- Analytical and Geochemistry Laboratory, Dept. of Energy and Environment, TERI School of Advanced Studies, New Delhi, India
| | - Chander Kumar Singh
- Analytical and Geochemistry Laboratory, Dept. of Energy and Environment, TERI School of Advanced Studies, New Delhi, India.
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Mukherjee A, Fryar AE, Eastridge EM, Nally RS, Chakraborty M, Scanlon BR. Controls on high and low groundwater arsenic on the opposite banks of the lower reaches of River Ganges, Bengal basin, India. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 645:1371-1387. [PMID: 30248860 DOI: 10.1016/j.scitotenv.2018.06.376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 06/22/2018] [Accepted: 06/29/2018] [Indexed: 06/08/2023]
Abstract
Understanding the controls on spatial variability of groundwater arsenic (As) is critical for mitigating As contamination. The objective of this study is to determine controls on previously unexplained differences in groundwater As concentrations, which are high along the east bank and low along the west bank of the River Bhagirathi-Hoogly (B-H), the primary Indian distributary of the River Ganges, on the western margin of the Bengal basin. A total of 54 wells were sampled after the monsoon season at four sites (two each east and west of the B-H) in Murshidabad district, West Bengal, for field parameters, major and minor solutes, and stable isotopes of water. An additional four boreholes were drilled for analyses of sediment texture, mineralogy, total organic and inorganic carbon, and total As and other metal(loid)s. Results show that higher As in east-bank groundwater (median 0.031 mg/L) is associated with generally more anoxic conditions (higher median total Fe and lower median EH and NO3-) relative to west-bank groundwater (median As < 0.001 mg/L), consistent with previous studies. In contrast, concentrations of Mn in the study area are highest in west-bank wells near the B-H. Carbonate and silicate weathering appear to be more important in east- and west-bank groundwater, respectively, which may reflect differences in sediment sources. Ranges of total As are similar in east- and west-bank sediments. Relatively depleted values of δ18O and δ2H in the east-bank aquifer and streams appear to reflect focused recharge through paleochannels, while relatively enriched west-bank values suggest diffuse recharge to upland aquifers. We speculate that water infiltrating through erosional, stratigraphic "windows" carries organic matter capable of mobilizing As in east-bank groundwater. This comprehensive evaluation of groundwater chemistry provides a more detailed understanding of controls on As variability within the basin.
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Affiliation(s)
- Abhijit Mukherjee
- Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur 721302, India; School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Alan E Fryar
- Department of Earth and Environmental Sciences, University of Kentucky, 101 Slone Building, Lexington, KY 40506-0053, USA
| | - Emily M Eastridge
- Department of Earth and Environmental Sciences, University of Kentucky, 101 Slone Building, Lexington, KY 40506-0053, USA
| | - Rachel S Nally
- Department of Earth and Environmental Sciences, University of Kentucky, 101 Slone Building, Lexington, KY 40506-0053, USA
| | - Madhumita Chakraborty
- Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur 721302, India
| | - Bridget R Scanlon
- Bureau of Economic Geology, University of Texas at Austin, University Station, Box X, Austin, TX 78713-8924, USA
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Jakobsen R, Kazmierczak J, Sø HU, Postma D. Spatial Variability of Groundwater Arsenic Concentration as Controlled by Hydrogeology: Conceptual Analysis Using 2-D Reactive Transport Modeling. WATER RESOURCES RESEARCH 2018; 54:10254-10269. [PMID: 31007297 PMCID: PMC6472640 DOI: 10.1029/2018wr023685] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 11/08/2018] [Accepted: 11/15/2018] [Indexed: 05/24/2023]
Abstract
Combined geological, hydrogeological, and geochemical controls on the arsenic concentration of contaminated aquifers in SE Asia were explored by two-dimensional (2-D) reactive transport modeling of data sets from Bangladesh, Cambodia, and Vietnam. For each site, the field data are summarized and used to create a conceptual 2-D reactive transport model that elucidates characteristic features influencing the groundwater arsenic concentration. Comparison of models for Bangladesh and Vietnam indicates that fine-grained layers overlying young sandy aquifers generate shallow high arsenic groundwater because low vertical groundwater velocities allow sufficient time for kinetic As release from the sediment. The low vertical groundwater velocity below major river channels, predicted by the model, also creates long groundwater residence times, leading to high arsenic groundwater. Young aquifer sediments release more arsenic than older sediments, and alternating young and older sediments create complex patterns of high and low arsenic groundwater. Over time, floodplain basins will subside, and river channels migrate, causing sedimentation and erosion on the floodplain while creating local environments with evolving hydrogeology and groundwater geochemistry. We have developed a three-step model for the evolution of the Red River floodplain with sedimentation and shifting channels over the last 6000 years. The results show comparable timescales between the dynamics of arsenic release and of river migration, causing complex groundwater As distributions, comprising geochemical palinopsia of long vanished rivers.
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Affiliation(s)
| | | | - Helle Ugilt Sø
- Geological Survey of Denmark and GreenlandCopenhagenDenmark
- Now at Ramboll Group A/SCopenhagenDenmark
| | - Dieke Postma
- Geological Survey of Denmark and GreenlandCopenhagenDenmark
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Sathe SS, Mahanta C, Mishra P. Simultaneous influence of indigenous microorganism along with abiotic factors controlling arsenic mobilization in Brahmaputra floodplain, India. JOURNAL OF CONTAMINANT HYDROLOGY 2018; 213:1-14. [PMID: 29598853 DOI: 10.1016/j.jconhyd.2018.03.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Revised: 02/13/2018] [Accepted: 03/02/2018] [Indexed: 06/08/2023]
Abstract
In the dynamic cycling of oxic and anoxic aqueous alluvial aquifer environments, varying Arsenic (As) concentrations are controlled by both abiotic and biotic factors. Studies have shown a significant form of toxic As (III) being released through the reductive dissolution of iron-oxy/hydroxide minerals and microbial reduction mechanisms, which leads to a serious health concern. The present study was performed in order to assess the abiotic and biotic factors influencing As release into the alluvial aquifer groundwater in Brahmaputra floodplain, India. The groundwater chemistry, characterization of the sediments, isolation, identification and characterization of prominent As releasing indigenous bacterium were conducted. The measured solid and liquid phases of total As concentration were ranged between 0.02 and 17.2 mg kg-1 and 8 to 353 μg L-1, respectively. The morphology and mineralogy showed the presence of detrital and authigenic mineral assemblages whereas primary and secondary As bearing Realgar and Claudetite minerals were identified, respectively. Furthermore, significant non-labile As fraction was found associated with the amorphous oxides of Fe, Mn and Al. The observed groundwater chemistry and sediment color, deduced a sub-oxic reducing aquifer conditions in As-contaminated regions. In addition, 16S rDNA sequencing results of the isolated bacterium showed the prominent Pseudomonas aeruginosa responsible for the mobilization of As, reducing condition, biomineralization and causing grey color to the sediments at the shallower and deeper aquifers in the study area. These findings suggest that microbial metabolic activities are equally responsible in iron-oxy/hydroxide reductive dissolution, controlling As mobilization in dynamic fluvial flood plains.
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Affiliation(s)
- Sandip S Sathe
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India.
| | - Chandan Mahanta
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati 781039, Assam, India
| | - Pushpanjali Mishra
- Department of Computer Science and Engineering, Sri Ramswaroop Memorial College of Engineering and Management, Lucknow 227105, Uttar Pradesh, India
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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.
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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
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10
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de Meyer CMC, Rodríguez JM, Carpio EA, García PA, Stengel C, Berg M. Arsenic, manganese and aluminum contamination in groundwater resources of Western Amazonia (Peru). THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 607-608:1437-1450. [PMID: 28763940 DOI: 10.1016/j.scitotenv.2017.07.059] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 07/06/2017] [Accepted: 07/07/2017] [Indexed: 06/07/2023]
Abstract
This paper presents a first integrated survey on the occurrence and distribution of geogenic contaminants in groundwater resources of Western Amazonia in Peru. An increasing number of groundwater wells have been constructed for drinking water purposes in the last decades; however, the chemical quality of the groundwater resources in the Amazon region is poorly studied. We collected groundwater from the regions of Iquitos and Pucallpa to analyze the hydrochemical characteristics, including trace elements. The source aquifer of each well was determined by interpretation of the available geological information, which identified four different aquifer types with distinct hydrochemical properties. The majority of the wells in two of the aquifer types tap groundwater enriched in aluminum, arsenic, or manganese at levels harmful to human health. Holocene alluvial aquifers along the main Amazon tributaries with anoxic, near pH-neutral groundwater contained high concentrations of arsenic (up to 700μg/L) and manganese (up to 4mg/L). Around Iquitos, the acidic groundwater (4.2≤pH≤5.5) from unconfined aquifers composed of pure sand had dissolved aluminum concentrations of up to 3.3mg/L. Groundwater from older or deeper aquifers generally was of good chemical quality. The high concentrations of toxic elements highlight the urgent need to assess the groundwater quality throughout Western Amazonia.
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Affiliation(s)
- Caroline M C de Meyer
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
| | - Juan M Rodríguez
- Facultad de Ciencias, Universidad Nacional de Ingeniería, Lima, Peru.
| | - Edward A Carpio
- Facultad de Ciencias, Universidad Nacional de Ingeniería, Lima, Peru
| | - Pilar A García
- Facultad de Ciencias, Universidad Nacional de Ingeniería, Lima, Peru
| | - Caroline Stengel
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland
| | - Michael Berg
- Eawag, Swiss Federal Institute of Aquatic Science and Technology, 8600 Dübendorf, Switzerland.
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11
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McArthur JM, Ghosal U, Sikdar PK, Ball JD. Arsenic in Groundwater: The Deep Late Pleistocene Aquifers of the Western Bengal Basin. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2016; 50:3469-76. [PMID: 27010474 DOI: 10.1021/acs.est.5b02477] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
in groundwaters from 145 wells across central West Bengal, India, those from Pleistocene aquifers at depths >70 m beneath paleo-interfluves contain <10 μg/L As. Pleistocene aquifers beneath deep paleo-channels typically host groundwaters containing 10-100 μg/L As at depths between 120 and 180 m. The depth profiles of As and SO4 and the conservative tracers Cl/Br, δ(18)O, and δ(2)H show that the As in Pleistocene groundwater beneath deep paleo-channels is relict and does not arise from migration downward of As-polluted groundwater in overlying aquifers. We postulate that the As was liberated in situ by reduction of minimal iron oxyhydroxides in the gray Pleistocene sands by organic matter infiltrating from riverbeds during late Pleistocene or earliest Holocene times. Mitigation of the widespread As-pollution in shallow aquifers through exploitation of deep Pleistocene aquifers would improve if guided by an understanding of the distribution of buried paleo-channels and paleo-interfluves and the knowledge that As may be present naturally in groundwater at depths >150 m beneath deep paleo-channels.
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Affiliation(s)
- J M McArthur
- Department of Earth Sciences, University College London , Gower Street, London WC1E 6BT, U.K
| | - U Ghosal
- Department of Environment Management, Indian Institute of Social Welfare and Business Management , College Square (West), Kolkata-700073, India
| | - P K Sikdar
- Department of Environment Management, Indian Institute of Social Welfare and Business Management , College Square (West), Kolkata-700073, India
| | - J D Ball
- School of Environmental Science, University of Liverpool , Brownlow Street, Liverpool L69 3GP, U.K
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Ghosal U, Sikdar PK, McArthur JM. Palaeosol Control of Arsenic Pollution: The Bengal Basin in West Bengal, India. GROUND WATER 2015; 53:588-99. [PMID: 25099955 DOI: 10.1111/gwat.12251] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 06/26/2014] [Indexed: 05/21/2023]
Abstract
Groundwater in the Bengal Basin is badly polluted by arsenic (As) which adversely affects human health. To provide low-As groundwater for As mitigation, it was sought across 235 km(2) of central West Bengal, in the western part of the basin. By drilling 76 boreholes and chemical analysis of 535 water wells, groundwater with <10 µg/L As in shallow aquifers was found under one-third of a study area. The groundwater is in late Pleistocene palaeo-interfluvial aquifers of weathered brown sand that are capped by a palaeosol of red clay. The aquifers form two N-S trending lineaments that are bounded on the east by an As-polluted deep palaeo-channel aquifer and separated by a shallower palaeo-channel aquifer. The depth to the top of the palaeo-interfluvial aquifers is mostly between 35 and 38 m below ground level (mbgl). The palaeo-interfluvial aquifers are overlain by shallow palaeo-channel aquifers of gray sand in which groundwater is usually As-polluted. The palaeosol now protects the palaeo-interfluvial aquifers from downward migration of As-polluted groundwater in overlying shallow palaeo-channel aquifers. The depth to the palaeo-interfluvial aquifers of 35 to 38 mbgl makes the cost of their exploitation affordable to most of the rural poor of West Bengal, who can install a well cheaply to depths up to 60 mbgl. The protection against pollution afforded by the palaeosol means that the palaeo-interfluvial aquifers will provide a long-term source of low-As groundwater to mitigate As pollution of groundwater in the shallower, heavily used, palaeo-channel aquifers. This option for mitigation is cheap to employ and instantly available.
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Affiliation(s)
- U Ghosal
- Department of Environment Management, Indian Institute of Social Welfare and Business Management, College Square (West), Kolkata, 700073, India
| | - P K Sikdar
- Department of Environment Management, Indian Institute of Social Welfare and Business Management, College Square (West), Kolkata, 700073, India
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Wilson CA, Goodbred SL. Construction and maintenance of the Ganges-Brahmaputra-Meghna delta: linking process, morphology, and stratigraphy. ANNUAL REVIEW OF MARINE SCIENCE 2015; 7:67-88. [PMID: 25251271 DOI: 10.1146/annurev-marine-010213-135032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We present a review of the processes, morphology, and stratigraphy of the Ganges-Brahmaputra-Meghna delta (GBMD), including insights gained from detailed elevation data. The review shows that the GBMD is best characterized as a composite system, with different regions having morphologic and stratigraphic attributes of an upland fluvial fan delta; a lowland, backwater-reach delta; a downdrift tidal delta plain; and an offshore subaqueous-delta clinoform. These distinct areas of upland and lowland fluvial reaches and tidal dominance vary in time and space, and we distinguish late-Holocene phases of delta construction, maintenance, and decline similar to delta-lobe cycling in other systems. The overall stability of the GBMD landform, relative to many deltas, reflects the efficient, widespread dispersal of sediment by the large monsoon discharge and high-energy tides that affect this region. However, we do identify portions of the delta that are in decline and losing elevation relative to sea level owing to insufficient sediment delivery. These areas, some of which are well inland of the coast, represent those most at risk to the continued effect of sea-level rise.
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Affiliation(s)
- Carol A Wilson
- Department of Earth and Environmental Sciences, Vanderbilt University, Nashville, Tennessee 37240; ,
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Biswas A, Bhattacharya P, Mukherjee A, Nath B, Alexanderson H, Kundu AK, Chatterjee D, Jacks G. Shallow hydrostratigraphy in an arsenic affected region of Bengal Basin: implication for targeting safe aquifers for drinking water supply. THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 485-486:12-22. [PMID: 24704952 DOI: 10.1016/j.scitotenv.2014.03.045] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2014] [Revised: 03/07/2014] [Accepted: 03/07/2014] [Indexed: 06/03/2023]
Abstract
To delineate arsenic (As) safe aquifer(s) within shallow depth, the present study has investigated the shallow hydrostratigraphic framework over an area of 100 km(2) at Chakdaha Block of Nadia District, West Bengal. Drilling of 29 boreholes and subsequent hydrostratigraphic modeling has identified three types of aquifer within 50 m below ground level (bgl). Aquifer-1 represents a thick paleochannel sequence, deposited parallel to the River Hooghly and Ichamati. Aquifer-2 is formed locally within the overbank deposits in the central floodplain area and its vertical extension is strictly limited to 25 m bgl. Aquifer-3 is distributed underneath the overbank deposits and represents an interfluvial aquifer of the area. Aquifer-3 is of Pleistocene age (~70 ka), while aquifer-1 and 2 represent the Holocene deposits (age <9.51 ka), indicating that there was a major hiatus in the sediment deposition after depositing the aquifer-3. Over the area, aquifer-3 is markedly separated from the overlying Holocene deposits by successive upward sequences of brown and olive to pale blue impervious clay layers. The groundwater quality is very much similar in aquifer-1 and 2, where the concentration of As and Fe very commonly exceeds 10 μg/L and 5 mg/L, respectively. Based on similar sediment color, these two aquifers have jointly been designated as the gray sand aquifer (GSA), which constitutes 40% (1.84×10(9) m(3)) of the total drilled volume (4.65×10(9) m(3)). In aquifer-3, the concentration of As and Fe is very low, mostly <2 μg/L and 1mg/L, respectively. This aquifer has been designated as the brown sand aquifer (BSA) according to color of the aquifer materials and represents 10% (4.8×10(8) m(3)) of the total drilled volume. This study further documents that though the concentration of As is very low at BSA, the concentration of Mn often exceeds the drinking water guidelines.
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Affiliation(s)
- Ashis Biswas
- KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm, Sweden; Department of Chemistry, University of Kalyani, Kalyani 741235, West Bengal, India.
| | - Prosun Bhattacharya
- KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm, Sweden
| | - Abhijit Mukherjee
- Department of Geology and Geophysics, Indian Institute of Technology-Kharagpur, Kharagpur 721302, West Bengal, India
| | - Bibhash Nath
- School of Geosciences, The University of Sydney, Sydney, NSW 2006, Australia
| | - Helena Alexanderson
- Department of Geology, Lund University, Sölvegatan 12, SE-223 62 Lund, Sweden
| | - Amit K Kundu
- Department of Chemistry, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Debashis Chatterjee
- Department of Chemistry, University of Kalyani, Kalyani 741235, West Bengal, India
| | - Gunnar Jacks
- KTH-International Groundwater Arsenic Research Group, Division of Land and Water Resources Engineering, Department of Sustainable Development, Environmental Science and Engineering, KTH Royal Institute of Technology, Teknikringen 76, SE-100 44 Stockholm, Sweden
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Mirlean N, Baisch P, Diniz D. Arsenic in groundwater of the Paraiba do Sul delta, Brazil: An atmospheric source? THE SCIENCE OF THE TOTAL ENVIRONMENT 2014; 482-483:148-156. [PMID: 24642100 DOI: 10.1016/j.scitotenv.2014.02.138] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2014] [Revised: 02/28/2014] [Accepted: 02/28/2014] [Indexed: 06/03/2023]
Abstract
High concentrations of arsenic (>50μg L(-1)) have been detected for the first time in groundwater of the wave-dominated Paraiba do Sul delta, Brazil. The deltaic shallow groundwater aquifer is enriched in arsenic fixed by authigenic sulfides. A study of palynomorphs confirmed that aquifer sediments were formed in inter-dune lakes/swamps lately covered by eolian sands. The organic sediments of contemporaneous inter-dune lake/swamp contain very high concentration of As: up to 180mg kg(-1) and 163μg L(-1) in dry gyttja material and interstitial water, respectively. The As in recent lake/swamp sediments is retained by iron hydroxides in upper and probably by sulfides in lower layers. In the absence of connection of inter-dune lakes/swamps with fluvial currents, the atmospheric input of As could be considered as the principal source in sediments. The calculation demonstrates the possibility of high concentrations of As accumulation in sediments of inter-dune lakes/swamps from atmospheric precipitations within several centuries before they will be covered by eolian sands and turned into shallow aquifer. Considering the commonalities of wave-dominated delta formations, we can predict more prevalent As accumulation in delta plain groundwater.
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Affiliation(s)
- N Mirlean
- Federal University of Rio Grande, Oceanography Institute, Brazil.
| | - P Baisch
- Federal University of Rio Grande, Oceanography Institute, Brazil
| | - D Diniz
- Federal University of Rio Grande, Oceanography Institute, Brazil
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Spatial and temporal evolutions of groundwater arsenic approximately along the flow path in the Hetao basin, Inner Mongolia. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s11434-013-5773-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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McArthur JM, Sikdar PK, Hoque MA, Ghosal U. Waste-water impacts on groundwater: Cl/Br ratios and implications for arsenic pollution of groundwater in the Bengal Basin and Red River Basin, Vietnam. THE SCIENCE OF THE TOTAL ENVIRONMENT 2012; 437:390-402. [PMID: 22960402 DOI: 10.1016/j.scitotenv.2012.07.068] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 07/19/2012] [Accepted: 07/22/2012] [Indexed: 05/02/2023]
Abstract
Across West Bengal and Bangladesh, concentrations of Cl in much groundwater exceed the natural, upper limit of 10 mg/L. The Cl/Br mass ratios in groundwaters range up to 2500 and scatter along mixing lines between waste-water and dilute groundwater, with many falling near the mean end-member value for waste-water of 1561 at 126 mg/L Cl. Values of Cl/Br exceed the seawater ratio of 288 in uncommon NO(3)-bearing groundwaters, and in those containing measurable amounts of salt-corrected SO(4) (SO(4) corrected for marine salt). The data show that shallow groundwater tapped by tube-wells in the Bengal Basin has been widely contaminated by waste-water derived from pit latrines, septic tanks, and other methods of sanitary disposal, although reducing conditions in the aquifers have removed most evidence of NO(3) additions from these sources, and much evidence of their additions of SO(4). In groundwaters from wells in palaeo-channel settings, end-member modelling shows that >25% of wells yield water that comprises ≥10% of waste-water. In palaeo-interfluvial settings, only wells at the margins of the palaeo-interfluvial sequence contain detectable waste water. Settings are identifiable by well-colour survey, owner information, water composition, and drilling. Values of Cl/Br and faecal coliform counts are both inversely related to concentrations of pollutant As in groundwater, suggesting that waste-water contributions to groundwater in the near-field of septic-tanks and pit-latrines (within 30 m) suppress the mechanism of As-pollution and lessen the prevalence and severity of As pollution. In the far-field of such sources, organic matter in waste-water may increase groundwater pollution by As.
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Affiliation(s)
- J M McArthur
- Department of Earth Sciences, University College London, Gower Street, London WC1E 6BT, UK.
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