title: Characterization of refuse landfill leachates of three different stages in landfill stabilization process.
abstract: Landfill leachates with different ages (mature leachate, 11 years; semi-mature leachate, 5 years; fresh leachate, under operation) were collected from Laogang Refuse Landfill, Shanghai to characterize the colloid size distribution and variations of leachate. These leachates were separated using micro-filtration and ultra-filtration into specific size fractions, i.e., suspended particles (SP) (> 1.2 microm), coarse colloids (CC) (1.2-0.45 microm), fine colloids (FC) (0.45 microm, 5 kDa/1 kDa molecular weight (MW)), and dissolved organic matters (DM, < 5 kDa/1 kDa MW). The specific colloids in each size fraction were quantified and characterized through chemical oxygen demands (COD), total solid (TS), pH, NH4+-N, total organic carbon (TOC) and fixed solid (FS). It was found that COD, NH4+-N and TS in leachate decreased significantly over ages, while pH increased. The dissolved fractions (< 5 kDa/1 kDa) dominated (over 50%) in three leachates in terms of COD, and the organic matter content in dissolved fraction of leachates decreased and the inorganic matter increased as the disposal time extended, with the TOC/COD ratio 30%-7%. Dissolved fractions decreased from 82% to 40% in terms of TOC as the disposal time extended, suggested that the organic matter remained in leachate would form into middle molecular weight substances during the degradation process.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiaotong University, Shanghai 200240, China. louworld12@sjtu.edu.cn
authors.forename: Ziyang
authors.initials: Z
authors.lastname: Lou
authors.forename: Bin
authors.initials: B
authors.lastname: Dong
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chai
authors.forename: Yu
authors.initials: Y
authors.lastname: Song
authors.forename: Youcai
authors.initials: Y
authors.lastname: Zhao
authors.forename: Nanwen
authors.initials: N
authors.lastname: Zhu
mesh_terms: D005374:Filtration; D008567:Membranes, Artificial; D016062:Porosity; D012037:Refuse Disposal
chemical_list: D008567:Membranes, Artificial