REMEDIATION OF SYNTHETIC AMD USING WASTE DERIVED ADSORBENTS AND BACTERIAL STRAINS (BACILLUS CEREUS MTCC-430)

Abstract

Acid mine drainage poses a significant environmental challenge due to its adverse effects on water quality and ecosystem health. This research work investigated the efficacy of various adsorbents, including raw eggshell, bagasse fly ash, iron slag, and rice husk ash, for removing contaminants from synthetic AMD. Results revealed that raw eggshells exhibited the highest removal efficiency, with almost complete removal of cations. Furthermore, the treated samples were analysed using various techniques, including XRD, FESEMEDX, FTIR, and MPAES, and spectrometry analysis to evaluate the metal removal efficiency and chemical composition of the generated sludge. The results indicated that raw eggshells exhibited the highest removal efficiencies, achieving > 99% removal of Fe, Zn, and Al and substantial removal of Ni, Co and Pb. Sulphate removal is around 58%. A bio-remediation step using Bacillus cereus MTCC 430 was further implemented to treat the AMD filtrate generated after treatment with raw eggshells to mitigate the concentration of sulphate and metal ions. The combined treatment of raw eggshell and Bacillus cereus MTCC 430 enhanced sulphate removal efficiency to 91.405% and improved the removal of Ni, Co, and Pb to >99%. Further, for Cu, and Mg the removal was more than 68%. The removal rate for Ca, and Mn, was 65.11%, and 98.4%, respectively. The findings highlight the potential of these adsorbents, particularly raw eggshells, along with bio-remediation of AMD and emphasise the importance of considering bio-remediation techniques for comprehensive treatment.