Hydrochemical signatures of industrial pollution: Impacts on surface and groundwater in the Aluva–Kochi Industrial Belt, Kerala, southern India

Water pollution caused by industrial activities poses a significant threat to surface and groundwater resources, particularly in regions with rapid industrialization. This study examines the impact of industrial pollution on the Periyar River and associated groundwater systems in the Aluva–Kochi Industrial Belt, Kerala, southern India. A comprehensive hydrochemical analysis of 50 water samples was conducted to assess drinking and irrigation suitability, identifying key constituents such as heavy metals, organic pollutants, and high salinity levels. The study employs multivariate statistical techniques, including hierarchical cluster analysis and Pearson correlation, to determine pollution sources and hydrogeochemical processes influencing water quality. Findings indicate elevated concentrations of heavy metals such as Ti, Ga, Ba, Sr, and Ag in the collected samples, with levels exceeding the permissible limits prescribed by WHO and BIS standards. Moreover, hydrogeochemical assessments reveal a transition from Ca–Mg–HCO3 to Na–Cl and Na–HCO3 water types, suggesting pollution from industrial discharge influence. The study highlights the urgent need for improved wastewater management and regulatory interventions to mitigate the adverse effects of industrial pollution on regional water resources. This study fills a critical gap by providing a comprehensive assessment of how industrial effluents contribute to hydrochemical alterations and water quality degradation in the Aluva–Kochi Industrial Belt of Kerala.