title: Column bioleaching copper and its kinetics of waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans.
abstract: Application of bioleaching process for metal recovery from electronic waste has received an increasing attention in recent years. In this work, a column bioleaching of copper from waste printed circuit boards (WPCBs) by Acidithiobacillus ferrooxidans has been investigated. After column bioleaching for 28d, the copper recovery reached at 94.8% from the starting materials contained 24.8% copper. Additionally, the concentration of Fe(3+) concentration varied significantly during bioleaching, which inevitably will influence the Cu oxidation, thus bioleaching process. Thus the variation in Fe(3+) concentration should be taken into consideration in the conventional kinetic models of bioleaching process. Experimental results show that the rate of copper dissolution is controlled by external diffusion rather than internal one because of the iron hydrolysis and formation of jarosite precipitates at the surface of the material. The kinetics of column bioleaching WPCBs remains unchanged because the size and morphology of precipitates are unaffected by maintaining the pH of solution at 2.25 level. In bioleaching process, the formation of jarosite precipitate can be prevented by adding dilute sulfuric acid and maintaining an acidic condition of the leaching medium. In such way, the Fe(2)(+)-Fe(3+) cycle process can kept going and create a favorable condition for Cu bioleaching. Our experimental results show that column Cu bioleaching from WPCBs by A. ferrooxidans is promising.
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China. Electronic address: crickswust@163.com.
authors.forename: Shu
authors.initials: S
authors.lastname: Chen
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China.
authors.forename: Yuankun
authors.initials: Y
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550002, China.
authors.forename: Congqiang
authors.initials: C
authors.lastname: Liu
authors.affiliation: Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, Mianyang 621010, China.
authors.forename: Faqin
authors.initials: F
authors.lastname: Dong
authors.affiliation: Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang 621900, China.
authors.forename: Bijun
authors.initials: B
authors.lastname: Liu
mesh_terms: D042763:Acidithiobacillus / Q000254:growth & development*; D003300:Copper / Q000302:isolation & purification*; D059029:Electronic Waste / Q000032:analysis*; D005290:Ferric Compounds / Q000032:analysis*; D007700:Kinetics; D059027:Recycling; D013431:Sulfates / Q000032:analysis*
chemical_list: D005290:Ferric Compounds; D013431:Sulfates; C492331:jarosite; D003300:Copper
keywords: Acidithiobacillus ferrooxidans; Column bioleaching; Copper recovery; Kinetic model; Waste printed circuit boards