Quantification of regional leachate variance from municipal solid waste landfills in China. (December 2015)

• Record Type: Journal Article
• Authors: Yang, Na; Damgaard, Anders; Kjeldsen, Peter; Shao, Li-Ming; He, Pin-Jing
• Is Part Of: Waste management. Volume 46(2015)
• Page Start: 362
• Page End: 372
• Publication Date: 2015-12
• Subjects: Municipal solid waste -- Leachate generation -- Hydrological modelling -- Precipitation infiltration -- Waste water squeezing -- Regional variation; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2015.09.016
• Languages: English
• ISSNs: 0956-053X

Abstract

Graphical abstract: Highlights: A leachate quantification method was established for MSW landfilling. Water squeezed out of waste is non-negligible for waste with high moisture content. Leachate generation performances differ in various geographic regions in China. Leachate amounts are significantly lower in northwestern China. Long-term generation contribute more than 60% in southern 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.