title: Copper leaching of MSWI bottom ash co-disposed with refuse: effect of short-term accelerated weathering.
abstract: Co-disposal of refuse with municipal solid waste incinerator (MSWI) bottom ash (IBA) either multi-layered as landfill cover or mixed with refuse could pose additional risk to the environment because of enhanced leaching of heavy metals, especially Cu. This study applied short-term accelerated weathering to IBA, and monitored the mineralogical and chemical properties of IBA during the weathering process. Cu extractability of the weathered IBA was then evaluated using standard leaching protocols (i.e. SPLP and TCLP) and co-disposal leaching procedure. The results showed that weathering had little or no beneficial effect on Cu leaching in SPLP and TCLP, which can be explained by the adsorption and complexation of Cu with DOM. However, the Cu leaching of weathered IBA was reduced significantly when situated in fresh simulated landfill leachate. This was attributed to weakening Cu complexation with fulvic acid or hydrophilic fractions and/or intensifying Cu absorption to neoformed hydr(oxide) minerals in weathered IBA. The amount of total leaching Cu and Cu in free or labile complex fraction (the fraction with the highest mobility and bio-toxicity) of the 408-h weathered IBA were remarkably decreased by 86.3% and 97.6% in the 15-day co-disposal leaching test. Accelerated weathering of IBA may be an effective pretreatment method to decrease Cu leaching prior to its co-disposal with refuse.
authors.affiliation: The State Key Laboratory of Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Tongji University, 200092 Shanghai, China.
authors.forename: Lianghu
authors.initials: L
authors.lastname: Su
authors.forename: Guangzhai
authors.initials: G
authors.lastname: Guo
authors.forename: Xinlong
authors.initials: X
authors.lastname: Shi
authors.forename: Minyu
authors.initials: M
authors.lastname: Zuo
authors.forename: Dongjie
authors.initials: D
authors.lastname: Niu
authors.forename: Aihua
authors.initials: A
authors.lastname: Zhao
authors.forename: Youcai
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000327:Adsorption; D001578:Benzopyrans / Q000737:chemistry; D060729:Coal Ash / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D062611:Solid Waste; D013997:Time Factors; D064091:Waste Disposal Facilities; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D001578:Benzopyrans; D060729:Coal Ash; D062611:Solid Waste; D014874:Water Pollutants, Chemical; D003300:Copper; C005023:fulvic acid