Bioremediation of soil polluted with cadmium and zinc using microflora from abattoir effluent

Abstract

Heavy metals are toxic and detrimental environmental pollutants. Their release into the environment could be a major cause of water and soil pollution majorly exacerbated by industrialization. This study was conducted to assess the ability of abattoir effluent to remediate soil contaminated with heavy metals such as, cadmium and zinc. Soil sample was artificially contaminated by adding 50g of Cd(NO₃)₂XH₂O and ZnClXH₂O to uncontaminated soil. The bacteria isolated and characterized from the abattoir effluent were Salmonella sp., Escherichia coli, Staphylococcus sp., Shigella sp., Pseudomonas sp., Enterobacter sp., Proteus sp., and Micrococcus sp. while the fungi species analyzed includes Aspergillus niger, Penicillium sp, Trichoderma sp, and Rhizopus sp. in the abattoir effluent. After remediation, the results showed significant (P < 0.05) reductions in heavy metal concentrations in the soil samples. Specifically, sample containing 200ml of abattoir effluent had the highest cadmium removal efficiency of 98% while sample containing 300ml of abattoir effluent recorded 79% removal performance in zinc. The study showed that microflora in abattoir effluent have the potential of removing heavy metals such as cadmium and zinc from polluted soil over a period of 3 weeks.