A novel method for the remediation of synthetic acid mine drainage using eggshell waste, H₂O₂ and KHCO₃

Acid mine drainage (AMD) is a challenging problem due to its environmental consequences. This study aims to remove contaminants from synthetic AMD with a novel treatment approach using calcined eggshell wastes in Fenton-like conditions. Treatment with 900 degrees C calcined eggshell waste was observed to be more impactful in comparison to raw and 600 degrees C calcined eggshell waste. However, treatment with 900 degrees C calcined eggshell waste in Fenton-like conditions has displayed outstanding treatment potential for synthetic AMD, with approximately complete removal (> 99 %) of cationic presence. Additionally, results indicate around 96 % removal of SO42- ions from synthetic AMD for an initial concentration of 19,500 +/- 100 ppm. Characterization of sludge validates the removal of metal ions and SO42- ions as detected by the MPAES and spectrometry analysis of treated water. The approximated cost analysis showed that the preparation cost of 900 degrees C calcined eggshell for large-scale production was 51 % less than the cost of conventionally used quicklime. The study provides novel insights into the mechanism of Fenton oxidation for AMD treatment. Based on the results, this method confirms the effective and economical treatment possibility with 900 degrees C calcined eggshell waste in Fenton-like conditions and can put forward a step for sustainable AMD treatment from waste.