title: Removal of heavy metals from fly ash leachate using combined bioelectrochemical systems and electrolysis.
abstract: Based on environmental and energetic analysis, a novel combined approach using bioelectrochemical systems (BES) followed by electrolysis reactors (ER) was tested for heavy metals removal from fly ash leachate, which contained high detectable levels of Zn, Pb and Cu according to X-ray diffraction analysis. Acetic acid was used as the fly ash leaching agent and tested under various leaching conditions. A favorable condition for the leaching process was identified to be liquid/solid ratio of 14:1 (w/w) and leaching duration 10h at initial pH 1.0. It was confirmed that the removal of heavy metals from fly ash leachate with the combination of BESs and ER is feasible. The metal removal efficiency was achieved at 98.5%, 95.4% and 98.1% for Cu(II), Zn(II), and Pb(II), respectively. Results of scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) indicated that Cu(II) was reduced and recovered mainly as metal Cu on cathodes related to power production, while Zn(II) and Pb(II) were not spontaneously reduced in BESs without applied voltage and basically electrolyzed in the electrolysis reactors.
authors.affiliation: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China. Electronic address: taohc@pkusz.edu.cn.
authors.forename: Hu-Chun
authors.initials: HC
authors.lastname: Tao
authors.affiliation: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Lei
authors.affiliation: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Shi
authors.affiliation: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Xiao-Nan
authors.initials: XN
authors.lastname: Sun
authors.affiliation: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Xue-Yan
authors.initials: XY
authors.lastname: Wei
authors.affiliation: Key Laboratory for Heavy Metal Pollution Control and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
authors.forename: Li-Juan
authors.initials: LJ
authors.lastname: Zhang
authors.affiliation: Department of Civil & Environmental Engineering, Center for Sustainable Development & Global Competitiveness, Stanford University, Stanford, CA 94305-4020, USA.
authors.forename: Wei-Min
authors.initials: WM
authors.lastname: Wu
mesh_terms: D060729:Coal Ash / Q000737:chemistry; D004572:Electrolysis; D005240:Feasibility Studies; D019216:Metals, Heavy / Q000302:isolation & purification*; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D060729:Coal Ash; D019216:Metals, Heavy
keywords: Bioelectrochemical systems; Electrolysis; Fly ash; Metal recovery