title: Quantification of regional leachate variance from municipal solid waste landfills in China.
abstract: The quantity of leachate is crucial when assessing pollution emanating from municipal landfills. In most cases, existing leachate quantification measures only take into account one source - precipitation, which resulted in serious underestimation in China due to its waste properties: high moisture contents. To overcome this problem, a new estimation method was established considering two sources: (1) precipitation infiltrated throughout waste layers, which was simulated with the HELP model, (2) water squeezed out of the waste itself, which was theoretically calculated using actual data of Chinese waste. The two sources depended on climate conditions and waste characteristics, respectively, which both varied in different regions. In this study, 31 Chinese cities were investigated and classified into three geographic regions according to landfill leachate generation performance: northwestern China (China-NW) with semi-arid and temperate climate and waste moisture content of about 46.0%, northern China (China-N) with semi-humid and temperate climate and waste moisture content of about 58.2%, and southern China (China-S) with humid and sub-tropical/tropical climate and waste moisture content of about 58.2%. In China-NW, accumulated leachate amounts were very low and mainly the result of waste degradation, implying on-site spraying/irrigation or recirculation may be an economic approach to treatment. In China-N, water squeezed out of waste by compaction totaled 22-45% of overall leachate amounts in the first 40 years, so decreasing the initial moisture content of waste arriving at landfills could reduce leachate generation. In China-S, the leachate generated by infiltrated precipitation after HDPE geomembranes in top cover started failing, contributed more than 60% of the overall amounts over 100 years of landfilling. Therefore, the quality and placing of HDPE geomembranes in the top cover should be controlled strictly for the purpose of mitigation leachate generation.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai 200092, China; Shenzhen Academy of Environmental Sciences, 50 Honggui Road, Shenzhen 518001, China.
authors.forename: Na
authors.initials: N
authors.lastname: Yang
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark. Electronic address: adam@env.dtu.dk.
authors.forename: Anders
authors.initials: A
authors.lastname: Damgaard
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark, 2800 Kongens Lyngby, Denmark.
authors.forename: Peter
authors.initials: P
authors.lastname: Kjeldsen
authors.affiliation: Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, China.
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Shao
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, 1239 Siping Road, Shanghai 200092, China; Institute of Waste Treatment and Reclamation, Tongji University, 1239 Siping Road, Shanghai 200092, China. Electronic address: solidwaste@tongji.edu.cn.
authors.forename: Pin-Jing
authors.initials: PJ
authors.lastname: He
mesh_terms: D002681:China; D002947:Cities; D002980:Climate; D004784:Environmental Monitoring / Q000379:methods*; D008962:Models, Theoretical; D064091:Waste Disposal Facilities; D018505:Waste Management; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Hydrological modelling; Leachate generation; Municipal solid waste; Precipitation infiltration; Regional variation; Waste water squeezing