title: Landfill CH4 oxidation by mineralized refuse: effects of NH4(+)-N incubation, water content and temperature.
abstract: Mineralized refuse, excavated from a municipal solid waste (MSW) landfill that had been closed for more than 10 years, was incubated in livestock wastewater for 150 d to accumulate ammonia-oxidizing bacteria and also co-oxidize methane (CH(4)). The extent of CH(4) oxidation and carbon dioxide (CO(2)) emissions from the incubated mineralized refuse (IMR) were investigated to assess its applicability as a bio-cover material at landfill sites for minimizing total greenhouse gas emission equivalents. From the initial 200 mg nitrogen (N) kg(-1) incubated for 120 h, the nitrate-N content produced in the IMR was twice (P<0.05) that of the untreated original mineralized refuse (OMR) and 3.81 (P<0.05) times that of soil. For an initial CH(4) concentration of approximately 10% by volume in the headspace, CH(4) consumption and net emission of CO(2) from the soil, IMR and OMR all agreed well with first-order and zero-order kinetics models for a 120-h incubation (R(2)=0.667 and R(2)=0.995, respectively). Similar to N turnover, the rate of consumption of CH(4) by the mineralized refuse was some 50.0% higher than for soil (P<0.05). Based on the net rate of CO(2) generation, the CH(4) oxidation rate by IMR was 14.2% (P>0.05) greater than for OMR and 56.1% (P>0.05) higher than for soil. Variation of water content and temperature produced substantially higher CH(4) consumption rates by IMR than by either OMR or soil. After treatment by livestock wastewater, the CH(4) oxidation capacity of mineralized refuse was moderately improved, due to the enhancement of CH(4) adsorption by retained suspended solids and the subsequent co-oxidation by the accumulated ammonia-oxidizing bacteria. By correlation analysis for the three experimental materials, CH(4) oxidation rate was significantly correlated with specific surface area and organic matter content (P<0.05), and was positively correlated with CO(2) generation, NH(4)(+)N nitrification and NO(3)(-)N generation rate (P>0.05).
authors.affiliation: Nanjing Institute of Environmental Sciences of the Ministry of Environmental Protection of PR China, Nanjing, Jiangsu, 210042, PR China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Houhu
authors.initials: H
authors.lastname: Zhang
authors.forename: Bo
authors.initials: B
authors.lastname: Jia
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Zhu
authors.forename: Tianyin
authors.initials: T
authors.lastname: Huang
authors.forename: Xiangji
authors.initials: X
authors.lastname: Kong
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry*; D000397:Air Pollution / Q000517:prevention & control*; D000641:Ammonia / Q000032:analysis / Q000737:chemistry*; D002245:Carbon Dioxide / Q000032:analysis; D008697:Methane / Q000032:analysis / Q000737:chemistry*; D058465:Nitrification; D009584:Nitrogen / Q000032:analysis / Q000737:chemistry*; D010084:Oxidation-Reduction; D012037:Refuse Disposal / Q000379:methods*; D014867:Water
chemical_list: D000393:Air Pollutants; D014867:Water; D002245:Carbon Dioxide; D000641:Ammonia; D009584:Nitrogen; D008697:Methane