Riparian Soil Heavy Metal Contamination and Pollution Assessment and Management Planning Integrating Multiple Indices, Statistical and Geospatial Approaches.

Abstract

This research assesses heavy metal contamination within the riparian zone of the Danro River, a tributary of the Ganges River basin in India, particularly impacted by sand mining activities. The study conducted analyses on major and trace elements in soil samples, focusing on those identified as ecologically hazardous by the Water Framework Directive of India. Utilizing a combination of indices (Enrichment Factor, Pollution Load Index, and Index of geo-accumulation) and statistical techniques such as Principal Component Analysis (PCA), the investigation aimed to evaluate contamination severity, ecological risks, and pollution sources. Results revealed arsenic concentrations ranging from 0.00-0.54 mg/kg to 117-136 mg/kg, and ecological risks for cadmium exceeding 30. PCA identified three dominant factors explaining over 95% of variance. This study also employed the Analytic Hierarchy Process (AHP) method to assess land use suitability. Results unveiled that chromium and nickel predominantly stemmed from natural origins, while arsenic, cadmium, lead, and zinc exhibited a mixed origin. While most sites displayed low to moderate contamination, south-western portion of the basin demonstrated significantly elevated copper concentrations. Cadmium emerged as a particular concern, posing downstream ecological risks alongside chromium, nickel, and zinc, surpassing established thresholds. Further examination using PCA analysis pinpointed three primary pollution sources: traffic emissions, industrial activities, and natural processes. The research concludes by proposing a novel approach for remediation, including the Miyawaki technique alongside traditional methods like electrokinetic remediation and soil leaching. Policy suggestions advocate for collaborative efforts between economic entities and governments to promote sustainable practices that minimize heavy metal pollution.