Assessment of the Toxic Characteristics and Pollution Potential of Leachate generated from a Municipal Solid Waste (MSW) landfill site in Guwahati, Assam, India

Abstract The disposal of Municipal Solid Waste (MSW) in unregulated landfills can have serious consequences for both the environment and human health. Landfills produce leachate, a major pollutant of soil and water. This liquid waste contains dissolved organic materials, heavy metals, hazardous substances, inorganic pollutants and suspended parti cles. This investigation focused on the characterisation of the leachate and its potential impact on the existing environment near the open dumping site located in West Boragaon, Guwahati, Assam, India. In total, 15 composite samples from varying distances were analysed for physico-chemical parameters and heavy metals, including Fe, Cu, Ni, Pb, Mn, Co, Cr, Zn, As, and Cd. The results revealed that the TDS (0.7–1.648 × 10 3 mg/L), TSS (1.1–1.8 × 10 3 mg/L), COD (1.693–2.526 × 10 3 mg/L), BOD (4.16–16.67 mg/L), TA (1.25–2.0 × 10 3 mg/L) and ions su ch as SO 4 2- (0.09–0.28 × 10 2 mg/L), Cl - (0.916–3.007 10 2 mg/L), Ca 2+ (1.002–2.104 × 10 2 mg/L), Mg 2+ (0.22– 0.548 × 10 2 mg/L), NO 3 - (0.43–0.83 mg/L), PO 4 3- (1.4–1.6 mg/L) which undergo significant variations. The average concentrations of heavy metals were in the order of: Fe > Mn > Zn > As > Cu > Ni > Cd > Co > Pb > Cr. The leachate pollution index (LPI) was 7.96 (~ 8) indicated moderate level of heavy metal pollution in the entire site. The I geo values for most of the heavy metals indicated moderate to high levels of pollution.