Appraisal of hydrochemistry and suitability assessment for water in an agriculture-dominated aquatic ecosystem of Rajasthan, India

Abstract

The study is the first comprehensive investigation of the water quality and geochemistry of an ecologically important large endorheic lake located in Rajasthan, India. The water quality and its suitability appraisal classified the water as fit for drinking, irrigation, and industrial application with the possible problem of corrosion. Most of the dissolved ions were observed to be coming from crustal/natural origin, with the exception of chloride. The water was observed to be MgHCO3 type and CaMgCl type based on the relative abundance of ions. Considering the environmental relevance towards eutrophication, the Nitrogen:Phosphorous (N:P) value of 10:1 in water classified the lake in transition from oligotrophic to eutrophic with an urgent need of intervention to arrest addition of domestic wastewater and agricultural runoff. Additionally, Fourier Transmission Infra-Red (FTIR) investigation of sediments and soil revealed that the chemical signatures of soil and sediments are similar, and most of the sediments are transported into the lake from a short distance. The geochemical classification of water and mineralogical profile of soil and sediments of the lake confirmed that rock–water interaction (silicate weathering in particular) is controlling the water chemistry via direct cation exchange. Considering the importance of lake as a hotspot for tourists, migratory birds, crocodile conservation, aquaculture and its application for irrigation and drinking, present study recommends effective management of water quality for its sustainable use.Graphical abstract