Environmental contamination by heavy metals and assessing the impact of inhabitant microalgae in bioremediation: a case study of urban water of Yamuna River, India

A study assessed the presence of heavy metals (HMs) in Yamuna River water across different locations, seasons, and years, while also examining the efficacy of resident microalgae in HMs removal. High HM concentrations were found, with peak levels in Faridabad during the summer of 2022: Cr(II) at 132.064 µg/L, Pb(II) at 93.034 µg/L, Cu(II) at 218.6 µg/L, and Ni(II) at 347.1 µg/L. In Kalindi Kunj during the same season and year, As(lII) measured 8.05 µg/L and Cd(II) reached 31.587 µg/L. The study identified microalgae species proficient in HMs removal. Scenedesmus sp. achieved 76.11% Cr(II) and 59.83% Pb(II) removal, while Klebsormidium sp. displayed the highest rates with 78.49% Cd(II) and 64.00% As(lII) removal. Oocystis sp. and Chlorococcum sp. absorbed up to 86.53% Cu(II) and 58.54% Ni(II), respectively. This research highlights the variability of HMs in Yamuna River water and the potential of resident microalgae for HMs remediation.