Metal Fractionation in Surface Sediments of the Brahmaputra River and Implications for Their Mobilization

Abstract

The Brahmaputra River is the largest tropical river in India that flows along the Himalayan regions and it is the lifeline of millions of people. Metal fractionation in the Brahmaputra River’s surface sediments and its correlation with turbidity are assessed in this study. The interaction between metal fractions and the overlying water is studied using multivariate statistical analyses. The strong positive correlation between NH4 of the overlying water and the exchangeable fractions in sediments signifies that the metals in the exchangeable fractions can be substituted by NH4. Subsequently, these metals can be released into the overlying water. The fluctuation in turbidity from 73 to 875 NTU indicates a large variation in the suspended matter concentration, and a higher concentration of suspended matter could provide attachment sites for pollutants such as metals. Significant variation in turbidity manifests a potentially high risk of pollution. In addition, the observation of local people along the Brahmaputra River turning its color to muddy indicates the need for continuous monitoring of water quality and an assessment of pollution is crucial. Although the Brahmaputra River’s risk assessment code is at low risk, the exchangeable fractions of Ni and Zn are present at all sites. Thus, the Brahmaputra River requires early preventive measures and management strategies to control metal pollution. This study contributes to an understanding of the fluctuation of turbidity of a tropical river. We provide baseline data for policymakers, and the importance of further intensive studies on metal pollution in the Himalayan Rivers is highlighted.

Identifying Most Suitable Priority Areas for Soil-Water Conservation Using Coupling Mechanism in Guwahati Urban Watershed

“…In addition, Yang et al (2021) employed the CCDM (coupling coordination model) and GIS spatial methodologies to examine the correlation, coupling, and coordination degrees between the geo-ecological environment and urbanization in Chongqing Municipality.Guwahati Metropolitan Area is one of the most urbanized areas in India, on the bank of the Brahmaputra River. Therefore, because of the urbanization, this river has experienced flow of domestic waste or sewages and industrial debris from the city, such as hazardous, chemical, industrial solid, and solid waste generated by municipalities (Pondari et al, 2020;Tsering et al, 2020). Little work has been done so far in the urban watershed of Guwahati, focusing on soil-water conservation modelling.…”