Evaluation of the fate of trace organic compounds using the Level III fugacity model: a case study of Rajbandh open dump site in Khulna City of Bangladesh

Abstract

Khulna is the 3rd largest city corporation in Bangladesh that produces 450 tons of Municipal solid waste (MSW) per day and dumps the waste in the Rajbandh open dump site. The main focus of this study is to determine the fate of chemicals in different environmental media at the Rajbandh open dump site. To accomplish the aim Level III fugacity model was evaluated which is subject to steady-state partitioning, reaction, advection, and intercompartmental transfer in an evaluative environment consisting of three compartments landfill gas (LFG), leachate, and waste. In this study, the model was implemented for six chemicals Trichloroethylene, Mono-chlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene, Hexachlorobenzene, and Benzene having different physiochemical properties. The result reveals that Benzene was found with the highest fugacity value of 2.03E + 00 Pa in all compartments while Hexachlorobenzene shows the highest value of concentration 2.67E-01 mol/m3 in the waste compartment. Regarding mass distribution, all chemical shows a higher mass remaining in the waste compartment in comparison with the other compartment. The result also reveals that the dominating removal process of a chemical from the system is the reaction process. For all the chemicals almost all the mass is removed from the environment by reaction process rather than advection in LFG and leachate. Finally, the estimated behavior of the selected chemical will help to evaluate the health and ecological hazards at the open dump site and take necessary steps to control the emission of such hazardous chemicals from the open dump site by the authority.