APPORTIONMENT OF LEACHATE TO GROUNDWATER POLLUTION AROUND UNCONTROLLED LANDFILL BY CHEMICAL MASS BALANCES

Abstract

To investigate the status of groundwater contamination around landfill site, groundwater samples from monitoring wells and existing wells were collected and analyzed. Chemical equilibrium program (MINTEQA2) and chemical mass balances (CMBs) were applied to get more information on pollutant speciation and the leachate behavior in the groundwater basin. From the chemical equilibrium model it is noticed that most of divalent metal ions in the contaminated groundwater are as the form of metal carbonate precipitates. Results showed that it was possible to estimate the mixing ratio of groundwater to leachate in monitoring well where the CMBs was applicable, and the fingerprints of groundwater quality of old landfill and currently active site were significantly different.