Simulating Effect of Potassium Carbonate on Quantity and Quality of Municipal Solid Waste Leachate

This study was aimed to assess the leachate properties of the treated municipal solid waste by potassium carbonate (K2CO3) obtained from a landfill located in Barmshour, Iran. Consequently, two bioreactors were filled with the same waste in the laboratory. Potassium carbonate was added to one of the reactors and then both bioreactors were cured under the same conditions for 6 months. The physico-chemical properties of the produced leachate such as the volume, pH, COD, BOD, metals and non-metal ion concentration were measured at different time intervals. Results indicated that the applied K2CO3 initially increased the leachate volume; however, it decreased the volume of leachate by 72.7% after 6 months. The pH of the control sample observed to be acidic (< 5) after 30 days. Adding K2CO3 prevented the reduction of the pH of leachate since it is an alkaline additive and the pH was measured 7.6-9.2 after 30 days. Furthermore, concentrations of all heavy metals were reduced in the leachate by adding potassium carbonate. At the end of the experiment, the COD and BOD of the reactor treated with K2CO3 were reduced by 39.4% and 37.8%, respectively. The leachate pollution index was calculated to be 28.1 and 19.4 after 180 days of the experiment for the untreated sample and potassium carbonate added sample, respectively. The overall results obtained in this study indicated that adding potassium carbonate to the waste can reasonably well improve the quality of leachate and can reduce its environmental hazards.