Performance study of compounded biocover material for methane removal based on cattle manure compost

Abstract

ABSTRACTMethane is the second most significant greenhouse gas. Landfill cover soils play an important role in mitigation of methane emission from critical sources – Landfills. In this study, methane removal biocover materials based on cattle manure compost (CMC) were constructed and its performance was investigated. When comparing CH4 removal abilities of sand (S), clay soil (CS), paddy soil (PS) and CMC, CMC was the most effective biocover material for the reduction of methane emission. The maximum removal rate (Vmax) and half saturation constant (Km) of CMC peaked at 3451.25 ± 18.57 μg g−1 h−1 and 3.67 ± 0.02 × 105 ppm, respectively, which are higher than those in previous studies. Thereafter, three compounded biocover materials (CBMs) were established based on the mixture of CMC and other three materials (ratio of 2:8). The rate of the three CBMs was enhanced by 13.56, 13.27 and 16.42 times, respectively, more than the S, CS and PS by adding CMC. Saturated water content of 80% and 35°C were found to be the optimum moisture and temperature, respectively, for CBMs. Analysis of community diversity using terminal restriction fragment length polymorphism (T-RFLP) showed that the diversity and evenness indexes of the CBMs decreased after adding CMC; Type I methanotroph was the most dominated methanotroph in the CBMs. CMC not only influenced bacterial community but also improved nutrient and CH4 removal capacity of CBMs. All results showed that CMC and CBMs could effectively remove CH4, and the screening and construction of CBMs are important for decreasing CH4 emission.