Remediation potential of (Pleurotus ostreatus and Eisenia fetida) on some heavy metals contents of crude oil polluted soil in Rivers State

Abstract

This study evaluated the effectiveness of Eisenia fetida (earthworm) and Pleurotus ostreatus (mushroom) in remediating heavy metals in  soil polluted with crude oil at concentrations of 0%, 5%, 7.5%, and 10% over six months. Standard chemical methods measured heavy  metal contents, revealing that levels of Lead, Iron, Chromium, and Cadmium increased with higher crude oil concentrations. Lead levels  rose from 0.39 mg/kg at 0% to 19.6 mg/kg at 10%, while Iron ranged from 26.1 to 3.27 mg/kg. After three months, mushrooms reduced heavy metals more effectively than earthworms, which showed minimal reduction at both three and six months. At 10% crude oil  pollution over six months, mushrooms reduced Lead by 90%, Iron by 95%, Chromium by 75%, and Cadmium by 64%. Earthworms reduced  lead by 70%, Iron by 60%, Chromium by 68%, and Cadmium by 54%. The study concluded that while both P. ostreatus and E.  fetida supported soil remediation, P. ostreatus was more effective.