Landfill CH_4 Oxidation, N_2O, and CO_2 Emissions from Wastewater-Incubated Mineralised Refuse: The Effect of Heavy Metal Addition and Environmental Factor Variations

摘要

The first investigations on anthropogenic methane (CH_4) oxidation and nitrous oxide (N_2O) emissions from mineralised refuse after wastewater treatment are reported. The maximum methane oxidation rate (MOR) in the incubated material was 15.48 μmol/g dry weight/h, which was substantially higher than those for the original mineralised refuse or soil. A correlation analysis (P＞0.05) showed that the mean particle size (D_(50)) value, organic matter content, NH_4~+-N nitrification, and NO_3~--N generation rates (P＜0.05) were highly positively correlated with the MOR for each of the three materials. The addition of heavy metals (i.e., Pb, Zn, Cr, and Cd) resulted in a 20 % decrease in MOR relative to the unamended control for both the incubated mineralised refuse (P＜0.05) and the original mineralised refuse (P＜0.05), and the MOR for soil decreased by 2.5 times relative to the control (P＞0.05). Following the addition of distilled water, N_2O emissions from the incubated mineralised refuse were almost two times and 1 order of magnitude greater than those of the MOR (P＞0.05) and soil (P＞0.05). The stimulation of N_2O emissions from the mineralised refuse could be neglected under the much higher MOR of a municipal solid waste landfill. Because of its high tolerance for environmental factor variations (i.e., soil temperature and water content) and heavy metal addition, mineralised refuse could be used to filter a wide variety of wastewaters to increase the MOR.