Impacts of Landfill Leachate on the Surrounding Environment: A Case Study on Amin Bazar Landfill, Dhaka (Bangladesh)

Abstract

Currently, a total of about 15,000 tons/day of waste is generated in the entire Dhaka city with an average per capita waste generation of 0.641 kg/day. Only 37% of this waste is collected and dumped into the two sanitary landfill sites, which is the only waste management system in Dhaka. To investigate the impact of landfill leachate of Amin Bazar landfill on the environmental compartments, a total of 14 composite samples (two leachates, three surface water, three groundwater, three soil, and three plants) were collected and analyzed for physicochemical parameters and heavy metal(loid)s concentration. Based on the result of physicochemical parameters, all results were found higher in the leachate samples than the permissible limit. The heavy metal(loid)s in leachate samples have a value of high levels of contamination. Surface water, groundwater, soil, and vegetation are all polluted as a result of high levels of metal contamination. Although the Water Quality Index values of the samples based on heavy metal(loid)s concentrations were within the acceptable range, heavy metal concentrations in the soil and plants were quite high. The concentrations of lead (Pb—8 mg/kg), cadmium (Cd—0.4 mg/kg), chromium (Cr—2.26 mg/kg), and cobalt (Co—1.72 mg/kg) in all plant samples were found to be higher than the allowable limit. The individual concentration of arsenic (As—0.021 mg/L) in the leachate was higher than the maximum allowed limit. Inverse Distance Weighted analysis through ArcGIS showed that landfill leachate has the maximum probability of contaminating the surrounding environment with heavy metal(loid)s. Results showed that samples collected near the landfill have higher concentrations of heavy metal(loid)s than others, which establishes the contribution of landfill leachate in contaminating the environment with heavy metal(loid)s. The improper leachate management of landfill has a high impact on the environment.