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Kumar P, Kumar M, Barnawi AB, Maurya P, Singh S, Shah D, Yadav VK, Kumar A, Kumar R, Yadav KK, Gacem A, Ahmad A, Patel A, Alreshidi MA, Singh V, Yaseen ZM, Cabral-Pinto MMS, Vinayak V, Wanale SG. A review on fluoride contamination in groundwater and human health implications and its remediation: A sustainable approaches. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2024; 106:104356. [PMID: 38158029 DOI: 10.1016/j.etap.2023.104356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 12/15/2023] [Accepted: 12/23/2023] [Indexed: 01/03/2024]
Abstract
Contamination of drinking water due to fluoride (F-) is a major concern worldwide. Although fluoride is an essential trace element required for humans, it has severe human health implications if levels exceed 1.5 mg. L-1 in groundwater. Several treatment technologies have been adopted to remove fluoride and reduce the exposure risk. The present article highlights the source, geochemistry, spatial distribution, and health implications of high fluoride in groundwater. Also, it discusses the underlying mechanisms and controlling factors of fluoride contamination. The problem of fluoride-contaminated water is more severe in India's arid and semiarid regions than in other Asian countries. Treatment technologies like adsorption, ion exchange, precipitation, electrolysis, electrocoagulation, nanofiltration, coagulation-precipitation, and bioremediation have been summarized along with case studies to look for suitable technology for fluoride exposure reduction. Although present technologies are efficient enough to remove fluoride, they have specific limitations regarding cost, labour intensity, and regeneration requirements.
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Affiliation(s)
- Pankaj Kumar
- Department of Environmental Science, Parul Institute of Applied Sciences, Parul University, Vadodara, Gujarat 391760, India.
| | - Manoj Kumar
- Department of Hydro and Renewable Energy, Indian Institute of Technology Roorkee, Roorkee, Uttarakhand 247667, India
| | - Abdulwasa Bakr Barnawi
- Department of Electrical Engineering, College of Engineering, King Khalid University, Abha 61421, Saudi Arabia
| | - Parul Maurya
- Department of Environmental Science & Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad 826004, Jharkhand, India
| | - Snigdha Singh
- Department of Environmental Science, Parul Institute of Applied Sciences, Parul University, Vadodara, Gujarat 391760, India
| | - Deepankshi Shah
- Department of Environmental Science, Parul Institute of Applied Sciences, Parul University, Vadodara, Gujarat 391760, India
| | - Virendra Kumar Yadav
- Department of Life Sciences, Hemchandracharya North Gujarat University, Patan, Gujarat 384265, India
| | - Anand Kumar
- School of Management Studies, Nalanda University, Rajgir, Bihar 803116, India
| | - Ramesh Kumar
- Department of Environmental Science, School of Earth Sciences, Central University of Rajasthan, Ajmer, Rajasthan 305817, India
| | - Krishna Kumar Yadav
- Faculty of Science and Technology, Madhyanchal Professional University, Ratibad, Bhopal, Madhya Pradesh 462044, India; Environmental and Atmospheric Sciences Research Group, Scientific Research Center, Al-Ayen University, Thi-Qar, Nasiriyah 64001, Iraq.
| | - Amel Gacem
- Department of Physics, Faculty of Sciences, University 20 Août 1955, Skikda 21000, Algeria
| | - Akil Ahmad
- Department of Chemistry, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
| | - Ashish Patel
- Department of Life Sciences, Hemchandracharya North Gujarat University, Patan, Gujarat 384265, India
| | | | - Vipin Singh
- Department of Chemistry, Faculty of Science, Dayalbagh Educational Institute, Dayalbagh, Agra 282005, India
| | - Zaher Mundher Yaseen
- Civil and Environmental Engineering Department, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Marina M S Cabral-Pinto
- Geobiotec Research Centre, Department of Geoscience, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Vandana Vinayak
- Diatom Nanoengineering and Metabolism Laboratory, School of Applied Science, Dr Harisingh Gour Central University, Sagar, Madhya Pradesh 470003, India
| | - Shivraj Gangadhar Wanale
- School of Chemical Sciences, Swami Ramanand Teerth Marathwada University, Nanded, Maharashtra 431606, India
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Malik A, Katyal D, Narwal N, Kataria N, Ayyamperumal R, Khoo KS. Sources, distribution, associated health risks and remedial technologies for inorganic contamination in groundwater: A review in specific context of the state of Haryana, India. ENVIRONMENTAL RESEARCH 2023; 236:116696. [PMID: 37482126 DOI: 10.1016/j.envres.2023.116696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Revised: 07/12/2023] [Accepted: 07/16/2023] [Indexed: 07/25/2023]
Abstract
Haryana is one of the leading states in India in the agricultural and industrial production. With the expansion of these sectors, a continuous increase in water demand is leading to water crises arising from overexploitation and quality deterioration of the available water. Contamination of aquifer resources is a significant concern, because majority of population depends on the groundwater for various agricultural, industrial, and domestic needs. This review article provides an overview of groundwater contamination, associated health risks with different contaminants with regions severely affected by poor water quality, and delves in identifying the sources, by observing and recognising the types of industries dominant in the state with types of effluents discharge. It further suggests the possible mitigation measures such as advanced remedial technologies and proper management practices from the consequent contamination sources. It has been observed during the perusal of various studies and data that the degree of contamination was considerably higher in districts with heavy agro-industrial activities. The groundwater resources in three highly industrialized districts were found to be gravely contaminated with toxic heavy metals. Alongwith heavy metals, the salinity, hardness, nitrate, and fluoride are also posing significant problems in the aquifer resources of Haryana state. The article also discusses various technologies for remediation of different pollutants from groundwater so it can be made potable after treatment.
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Affiliation(s)
- Aastha Malik
- University School of Environment Management, Guru Gobind Singh Indraprastha University, New Delhi, 110078, India
| | - Deeksha Katyal
- University School of Environment Management, Guru Gobind Singh Indraprastha University, New Delhi, 110078, India.
| | - Nishita Narwal
- University School of Environment Management, Guru Gobind Singh Indraprastha University, New Delhi, 110078, India
| | - Navish Kataria
- Department of Environmental Sciences, J. C. Bose University of Science & Technology, YMCA, Faridabad, 121006, Haryana, India
| | | | - Kuan Shiong Khoo
- Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan, Taiwan; Centre for Herbal Pharmacology and Environmental Sustainability, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, 603103, Tamil Nadu, India.
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3
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Huang X, Han Y, Xiao Z, Wang S, Wang S, Zhang M, Zeng T, Tang L, Li H, Qi S. Fluoride occurrence in geothermal water of fault zone area, Southeast China. CHEMOSPHERE 2023; 328:138468. [PMID: 36948255 DOI: 10.1016/j.chemosphere.2023.138468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 03/08/2023] [Accepted: 03/19/2023] [Indexed: 06/18/2023]
Abstract
Fluoride (F-) is a common trace component in groundwater, and long-term exposure to high-F- groundwater is harmful to human health. Fluoride concentrations that exceed the World Health Organization guideline for drinking water (1.5 mg/L) have been detected in thermal and non-thermal groundwater from Southeast China, where the causes of the high fluoride occurrence are lack of study. To study the formation and migration mechanism of high fluoride groundwater from Southeast China, we carried out a systemic sampling of water samples in the surrounding area of Heyuan deep fault zone and Zijin-Boluo fault zone, then a comprehensive discussion including water hydrogeochemical, stable isotope composition, as well as hydrogeology analysis was conducted. Fluoride concentrations in geothermal and non-thermal water samples range from 1.11 to 22.76 mg/L and 0.04-8.3 mg/L, respectively. High temperature, alkaline conditions, and the depleted Ca2+ by reverse cation exchange and calcite precipitation would promote the release of fluoride from host rock to geothermal water. The availability of Ca-bearing and F-bearing minerals in host rock causes significant differences in fluoride concentrations between carbonate reservoir and granite reservoir. Hydrochemical diagrams reveal that the composition of groundwater is affected by mixing and that fractures act as the mixing channels in our study area. The addition of cold groundwater limits the fluoride concentrations by lowing temperature and increasing Ca2+ levels of geothermal water. Additionally, the relationship between F- and SiO2 indicates that geothermal water promotes the fluoride enrichment in cold groundwater, especially in confined aquifers which are more susceptible to geothermal water. The direct input of geothermal fluoride and secondary enrichment caused by alkaline condition contribute to the formation of high F- concentrations (7.2-8.3 mg/L) in confined groundwater. Our findings highlight that the natural evolution of geothermal systems in fault zone can result in the formation of geogenic contaminated groundwater.
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Affiliation(s)
- Xuelian Huang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China; School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China
| | - Yongjie Han
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China
| | - Zhicai Xiao
- School of Applied Technology, Lijiang Normal University, Lijiang, 674199, China
| | - Shuai Wang
- School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China; School of Resources, China University of Geosciences, Wuhan, 430074, China
| | - Sijia Wang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China
| | - Min Zhang
- Team 935, Geology Bureau for Nonferrous Metals of Guangdong Province, Huizhou, 516001, China
| | - Turong Zeng
- No.4 Geological Brigade, Guangdong Geological Bureau, Zhanjiang, 524049, China
| | - Ling Tang
- Team 935, Geology Bureau for Nonferrous Metals of Guangdong Province, Huizhou, 516001, China
| | - Hailong Li
- Chinese Academy of Geological Sciences, Beijing, 100037, China
| | - Shihua Qi
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan, 430078, China; School of Environmental Studies, China University of Geosciences, Wuhan, 430078, China.
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Kumar R, Sharma P, Sharma PK, Rose PK, Singh RK, Kumar N, Sahoo PK, Maity JP, Ghosh A, Kumar M, Bhattacharya P, Pandey A. Rice husk biochar - A novel engineered bio-based material for transforming groundwater-mediated fluoride cycling in natural environments. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 343:118222. [PMID: 37235991 DOI: 10.1016/j.jenvman.2023.118222] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 04/25/2023] [Accepted: 05/19/2023] [Indexed: 05/28/2023]
Abstract
Biochar, a promising carbon-rich and carbon-negative material, can control water pollution, harness the synergy of sustainable development goals, and achieve circular economy. This study examined the performance feasibility of treating fluoride-contaminated surface and groundwater using raw and modified biochar synthesized from agricultural waste rice husk as problem-fixing renewable carbon-neutral material. Physicochemical characterizations of raw/modified biochars were investigated using FESEM-EDAX, FTIR, XRD, BET, CHSN, VSM, pHpzc, Zeta potential, and particle size analysis were analyzed to identify the surface morphology, functional groups, structural, and electrokinetic behavior. In fluoride (F-) cycling, performance feasibility was tested at various governing factors, contact time (0-120 min), initial F- levels (10-50 mg L-1), biochar dose (0.1-0.5 g L-1), pH (2-9), salt strengths (0-50 mM), temperatures (301-328 K), and various co-occurring ions. Results revealed that activated magnetic biochar (AMB) possessed higher adsorption capacity than raw biochar (RB) and activated biochar (AB) at pH 7. The results indicated that maximum F- removal (98.13%) was achieved using AMB at pH 7 for 10 mg L-1. Electrostatic attraction, ion exchange, pore fillings, and surface complexation govern F- removal mechanisms. Pseudo-second-order and Freundlich were the best fit kinetic and isotherm for F- sorption, respectively. Increased biochar dose drives an increase in active sites due to F- level gradient and mass transfer between biochar-fluoride interactions, which reported maximum mass transfer for AMB than RB and AB. Fluoride adsorption using AMB could be described through chemisorption processes at room temperature (301 K), though endothermic sorption follows the physisorption process. Fluoride removal efficiency reduced, from 67.70% to 53.23%, with increased salt concentrations from 0 to 50 mM NaCl solutions, respectively, due to increased hydrodynamic diameter. Biochar was used to treat natural fluoride-contaminated surface and groundwater in real-world problem-solving measures, showed removal efficiency of 91.20% and 95.61%, respectively, for 10 mg L-1 F- contamination, and has been performed multiple times after systematic adsorption-desorption experiments. Lastly, techno-economic analysis was analyzed for biochar synthesis and F- treatment performance costs. Overall, our results revealed worth output and concluded with recommendations for future research on F- adsorption using biochar.
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Affiliation(s)
- Rakesh Kumar
- School of Ecology and Environment Studies, Nalanda University, Rajgir, Bihar 803116, India.
| | | | - Pushpa Kumari Sharma
- Aryabhatta Centre for Nanoscience & Nanotechnology, Aryabhatta Knowledge University, Patna, Bihar 800001, India
| | - Pawan Kumar Rose
- Department of Energy and Environmental Sciences, Chaudhary Devi Lal University, Sirsa, Haryana 125055, India
| | - Rakesh Kumar Singh
- Aryabhatta Centre for Nanoscience & Nanotechnology, Aryabhatta Knowledge University, Patna, Bihar 800001, India
| | - Nishant Kumar
- Aryabhatta Centre for Nanoscience & Nanotechnology, Aryabhatta Knowledge University, Patna, Bihar 800001, India
| | - Prafulla Kumar Sahoo
- Department of Environmental Sciences and Technology, School of Environment and Earth Sciences, Central University of Punjab, Bathinda, Punjab 151001, India
| | - Jyoti Prakash Maity
- Environmental Science Laboratory, Department of Chemistry, School of Applied Sciences, KIIT Deemed to be University, Bhubaneswar, Odisha 751024, India
| | - Ashok Ghosh
- Mahavir Cancer Sansthan and Research Centre, Phulwarisharif, Patna 801505, Bihar, India; Bihar State Pollution Control Board, Patna, Bihar 800010, India
| | - Manish Kumar
- Sustainability Cluster, School of Engineering, University of Petroleum and Energy Studies, Dehradun, Uttarakhand 248007, India; Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Monterrey, Eugenio Garza Sada 2501 Sur, Monterrey 64849, Mexico.
| | - Prosun Bhattacharya
- Department of Sustainable Development, Environmental Sciences and Engineering, KTH Royal Institute of Technology, Teknikringen 10B SE-100 44 Stockholm, Sweden; KWR Water Cycle Research Institute, Groningenhaven 7, 3433 PE, Nieuwegein, the Netherlands
| | - Ashok Pandey
- Sustainability Cluster, School of Engineering, University of Petroleum and Energy Studies, Dehradun, Uttarakhand 248007, India; Centre for Innovation and Translational Research, CSIR-Indian Institute of Toxicology Research, Lucknow 226 001, India
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Muthu Prabhu S, Yusuf M, Ahn Y, Park HB, Choi J, Amin MA, Yadav KK, Jeon BH. Fluoride occurrence in environment, regulations, and remediation methods for soil: A comprehensive review. CHEMOSPHERE 2023; 324:138334. [PMID: 36893864 DOI: 10.1016/j.chemosphere.2023.138334] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/04/2023] [Accepted: 03/06/2023] [Indexed: 06/18/2023]
Abstract
Fluoride, a naturally occurring chemical element, is largely insoluble in soils. More than 90% of the fluoride in soil is bound to soil particles and is unable to be dissolved. As part of the soil, fluoride is predominantly located in the colloid or clay fraction of the soil, and the movement of fluoride is strongly affected by the sorption capacity of the soil, which is affected by pH, the type of soil sorbent present, and the salinity. The Canadian Council of Ministers of the Environment soil quality guideline for fluoride in soils under a residential/parkland land use scenario is 400 mg/kg. In this review, we focus on fluoride contamination in soil and subsurface environments, and the various sources of fluorides are discussed in detail. The average fluoride concentration in soil in different countries and their regulations for soil and water are comprehensively reviewed. In this article, the latest advances in defluoridation methods are highlighted and the importance of further research addressing efficient and cost-effective methods to remediate fluoride contamination in soil is critically discussed. Methods used to mitigate fluoride risks by removing fluoride from the soil are presented. We strongly recommend that regulators and soil chemists in all countries explore opportunities to improve defluoridation methods and consider adopting more stringent regulations for fluoride in soil depending on geologic conditions.
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Affiliation(s)
- Subbaiah Muthu Prabhu
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea; Department of Chemistry, School of Advanced Sciences, VIT-AP University, Vijayawada, 522 237, Andhra Pradesh, India
| | - Mohammed Yusuf
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea
| | - Yongtae Ahn
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
| | - Ho Bum Park
- Department of Energy Engineering, Hanyang University, Seoul, 04763, Republic of Korea
| | - Jaeyoung Choi
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, Hwarang-ro 14, Seongbuk-gu, Seoul, 02792, Republic of Korea
| | - Mohammed A Amin
- Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif, 21944, Saudi Arabia
| | - Krishna Kumar Yadav
- Faculty of Science and Technology, Madhyanchal Professional University, Tatibad, Bhopal, 462044, India
| | - Byong-Hun Jeon
- Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
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Sarkar S, Mukherjee A, Chakraborty M, Quamar MT, Duttagupta S, Bhattacharya A. Prediction of elevated groundwater fluoride across India using multi-model approach: insights on the influence of geologic and environmental factors. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:31998-32013. [PMID: 36459318 DOI: 10.1007/s11356-022-24328-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 11/16/2022] [Indexed: 06/17/2023]
Abstract
Elevated fluoride in groundwater is a severe problem in India due to its extensive occurrence and detrimental health impacts on the large population that thrives on groundwater. Although fluoride is primarily a geogenic pollutant, existing model-based studies lack the amalgamation of the influence of geologic factors, specifically tectonics, for identifying groundwater fluoride distribution. This drawback encourages the present study to investigate the association of the tectonic framework with fluoride in a multi-model approach. We have applied three machine learning models (random forest, boosted regression tree, and logistic regression) to predict elevated groundwater fluoride based on fluoride measurements across India. The random forest model outperformed other models with an accuracy of 93%. Tectonics was found to be one of the most important predictors alongside "depth to water table." Two major areas of high risk identified were the northwest parts and the south-southeast cratonic peninsular region. The random forest model also performed significantly well over the validation dataset. We estimate that nearly 257 million people are exposed to elevated fluoride risk in India. We endeavor that the findings of our study would be an effective tool for identifying the areas at risk of elevated fluoride and also assist in undertaking effective groundwater management strategies.
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Affiliation(s)
- Soumyajit Sarkar
- School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, West Bengal, India
| | - Abhijit Mukherjee
- School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, West Bengal, India.
- Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur, 721302, West Bengal, India.
| | - Madhumita Chakraborty
- Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur, 721302, West Bengal, India
| | - Md Tahseen Quamar
- Department of Geology and Geophysics, Indian Institute of Technology Kharagpur, Kharagpur, 721302, West Bengal, India
| | - Srimanti Duttagupta
- Graduate School of Public Health, San Diego State University, San Diego, CA, 92182, USA
| | - Animesh Bhattacharya
- School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, West Bengal, India
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Yapo NS, Aw S, Briton BGH, Drogui P, Yao KB, Adouby K. Removal of fluoride in groundwater by adsorption using hydroxyapatite modified Corbula trigona shell powder. CHEMICAL ENGINEERING JOURNAL ADVANCES 2022. [DOI: 10.1016/j.ceja.2022.100386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
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Subba Rao N, Das R, Gugulothu S. Understanding the factors contributing to groundwater salinity in the coastal region of Andhra Pradesh, India. JOURNAL OF CONTAMINANT HYDROLOGY 2022; 250:104053. [PMID: 35981428 DOI: 10.1016/j.jconhyd.2022.104053] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 07/10/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
The present study focused on understanding the factors responsible for groundwater salinity in the coastal region, Prakasam district, Andhra Pradesh, India. Groundwater samples were collected and analysed for pH, EC, TDS, TA, TH, CH, NCH, EA, Ca2+, Mg2+, Na+, K+, HCO3-, Cl-, SO42-, NO3-, and F-. Groundwater quality was assessed using entropy weighted water quality index (EWQI), Chadha and Gibbs diagrams, ionic ratios, chloro-alkaline indices (CA), saturation indices (SI), principal component analysis (PCA), and hierarchical cluster analysis (HCA). TDS vs TH indicated that 86% of groundwater samples fall under brackish-cum-very hard water-quality type, while TA and TH relationship showed that 70% and 30% of groundwater samples fall under non‑carbonate hardness (NCH) and excess alkalinity (EA), respectively. EWQI classified groundwater samples into medium (22%), poor (40%), and exremely poor (38%) water quality types, indicating that most samples are not suitable for drinking purposes. Hydrogeochemical types in Chadha diagram showed saline water (Na+-Cl-) type in 92% of groundwater samples. Ionic ratios indicated that anthropogenic activities resulting from the leaching of surface water pollutants are the main source of groundwater pollution. Base ion exchange was indicated as the main process in CA indices. SI revealed precipitation of the calcite phase and dissolution of the gypsum and halite phases in groundwater. Evaporation appeared in Gibb's diagram as a primary process rather than a geogenic origin. PC1 (Na+, Cl-, SO42-, Mg2+, K+, and NO3-) and PC2 (HCO3- and F-) were considered salinity-process and alkalinity-process, respectively. The main sources of salinity in groundwater are brackish-water aquaculture and salt-making activities with household waste, septic tank spills, irrigation-return-flows, and chemical fertilizers being secondary sources. HCA classified groundwater samples into Group-I (46%), which represents domestic water, agricultural activities, etc., Group-II (30.24%), which shows the influence of both Group-I and Group-II, and Group-III (23.76%), which specifies brackish-water aquaculture and salt-making activities. Consequently, the present study obviously indicated that the groundwater quality of anthropogenic origin has largely overcome the influence of geogenic sources. The EWQI classification spatially delineated the study region into medium, high, and very high vulnerable zones, covering 28.69%, 32.75%, and 38.56%, respectively. Therefore, it is suggested to control the dumping of domestic waste and septic tank leaks, limit irrigation-return-flows and chemical fertilizers, ban brackish water aquaculture and salt production activities, and strictly implement an aquifer recharge management strategy to ensure human health. This study will assist decision-makers in addressing groundwater salinity issues in coastal regions.
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Affiliation(s)
- N Subba Rao
- Department of Geology, Andhra University, Visakhapatnam 530 003, Andhra Pradesh, India.
| | - Rashmirekha Das
- Department of Geology, Utkal University, Bhubaneswar 751 004, Odisha, India
| | - Sakram Gugulothu
- CSIR-National Geophysical Research Institute, Hyderabad 500 007, Telangana, India
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