Arsenic and heavy metal contamination, enrichment processes, and health risk assessment in groundwater of Bijnor district, Upper Gangetic plain, India

Abstract

An investigation on groundwater quality assessment was carried out in Bijnor District, upper Gangetic plain, India to demarcate the general geochemical characteristics, hydrochemical processes that are evolving the groundwater, heavy metal contamination, and their enrichment mechanism and prepare a map of their spatial distribution across the study area. The majority of the study region lies beneath quaternary alluvial sediments deposited by the rivers Ganga and Ramganga drainage systems. A total of 41 groundwater samples were collected from both governments as well as private wells in all the five tehsils of the Bijnor District. Groundwater samples were analyzed for pH, EC, Eh, and TDS at the field, major anions viz., F-, Cl-, NO2-, NO3-, SO42-, and major cations viz., Li, Na, NH4, K, Ca, and Mg were determined by the Ion Chromatography (IC) equipment and heavy metals viz., Cr, Mn, Fe, Co, Ni, As, Cd and Pb were determined using Inductively Coupled Plasma Mass Spectrometry (ICPMS-MS). Piper diagram was drawn for the hydrochemical facies classification and heavy metal pollution indices were evaluated to determine their contamination. pH value indicates the highly alkaline groundwater in the region. Mg bicarbonate is found as the dominating hydrochemical facies in the groundwater. Sediment water interaction is playing an important role in groundwater evolution. Out of 41 samples, 9 samples collected have As value above the guideline limit of 10 µg/L. The spatial distribution suggested that higher contamination of As is occurring in the southern region of the Bijnor district. Therefore, the southern portion should be the primary health, ecological and environmental concern.