Bioremediation potential of biochar and metal tolerant Bacillus cereus on heavy metal polluted mine surrounding pond and assessed cytotoxicity and phytotoxicity attributes of treated water on Brine shrimp larvae and Paddy seedling

Abstract

BackgroundThe soil has been polluted severely with metals leached from mine tailings. Thus, these mine tailings can also reduce the fertility of farmland nearby the mining activities. The research was performed to assess the physicochemical attributes of water sample collected from magnesite mine surrounding pond and evaluate the bioremediation potential of pre-characterized biochar and Bacillus cereus under various treatments set up in a laboratory condition. MethodsStandard acid digestion method was followed to quantify the metal content in the soil. In-vitro remediation method was performed to determine the remediation potential of biochar and B. cereus. In-vitro method was followed to find the toxicity on Artemia franciscana larvae and Orysa sativa. FindingsThe results shows that the heavy metal contents like As, Cd, Pb, Cr, Cu, Zn, Cl−, SO42−, as well as Hg beyond the permissible limit. The dissolved oxygen (DO) level was also notably poor. The bioremediation study with various treatment groups (BT1, BT2, BT3, and BT4) showed that the group BT2 (biochar + B. cereus) effectively reduced the heavy metals in the treated pond water under 10 days of exposure. Furthermore, the BT2 treated water sample alone showed no toxic effects on A. franciscana larvae and O. sativa.