Heavy metals contamination in sediments of Bharalu river, Guwahati, Assam, India: A tributary of river Brahmaputra

Abstract

This study aimed to assess heavy metals in the surface sediments of the Bharalu river, India. Metal concentrations ranged from 6.65−54.6 mg/kg for Ni, 25.2−250.0 mg/kg for Zn, 83.3−139.1 mg/kg for Pb, and 11940.0−31250.0 mg/kg for Fe. The level of metal contamination was assessed using sediment quality guidelines, geo-accumulation index (Igeo), enrichment factor (EF), pollution Load Index (PLI),Nemerow’s pollution index (PIN), and potential ecological risk index. Pb exceeded the sediment quality guidelines at all sites indicating a potential threat to the river ecosystem. (Igeo) and EF also showed moderate to severe enrichment for Pb. Potential ecological risk (RI) showed low risk in the sediments, and Pb is the major contributor to ecological risk. Overall, pollution indices revealed comparably higher contamination of the sediments in the downstream sites than in the upstream site. PCA and correlation matrix analysis indicated both anthropogenic and natural origins for metals. Among anthropogenic sources, urban discharges and waste dumping could be mainly attributed to metal contamination in the river sediments. These findings may aid in developing future river management methods explicitly aimed at tackling heavy metal pollution to prevent further damage to the river ecosystem.

Pollution Induced-stress on Biodiversity and Restoration Strategy for India’s Heavily Contaminated Bharalu River

“…Bharalu serves as the natural drainage of the city and the river carries sewage and wastage from markets, commercial establishments, hotels, restaurants, schools etc. Parties to this decimation have been the vegetable & fish markets, the hotels & restaurants and the insensitive, callous, and apathetic citizens who throw household garbage into the river without batting an eyelid [1]. Many inhabitants have even directed their sewage outlet pipes on to the Bharalu thereby little realizing that the serious health hazard caused by their action will backfire on themselves and the city dwellers one day.…”