Heavy metal contamination of sediments and water of indian sundarban: implications on biofilm growth

Abstract

Multi-species intertidal biofilms have a high level of stress tolerance due to their extended exposure to the dynamic environmental conditions facilitating in-situ sequestration of contaminants. Heavy metals tend to accumulate in these intertidal sediments and eventually get desorbed with changing physicochemical conditions. Once released to the overlying water they become bioavailable to living organisms, making the sediments a potential secondary source of metal pollutants. The focus of our study is to identify the partition of heavy metals (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, V, Zn) in biofilms (absorbed and adsorbed), water and sediments across salinity gradient in intertidal sediment of Sundarbans during the winter season (1st week of January, 2023). In this study, we also measured the different physico-chemical parameters of water and we find out the correlation between the environmental factors and metals concentration. We also measured the CF, EF, Igeo, and RI of heavy metals according to the location to find out the source of those metals. The contamination factor (CF), geo-accumulation index (Igeo), and ecological risk index (ERI) highlighted that the sampling areas were mostly exposed to Ni, Cd contamination. The multivariate statistical techniques such as Factor Analysis (FA) have been widely used for identifying sources of pollution and their spatial distribution in the river network. To maintain the sound environment and healthy ecosystem of the river and the surrounding areas, need proper management and monitoring of water quality of the river.