title: Biosynthesis of bifunctional iron oxyhydrosulfate by Acidithiobacillus ferroxidans and their application to coagulation and adsorption.
abstract: Coagulation and adsorption are important environmental technologies, which were widely applied in water treatment. In this study, a type of villous iron oxyhydrosulfate with low crystallinity, high content iron, sulfate and hydroxyl was synthesized by Acidithiobacillus ferrooxidans, which possessed coagulation and heavy metal adsorption ability simultaneously. The results showed that the Cu(II) adsorption capacity increased within a small range over the pH range of 3.0-5.0 but increased evidently over the range of 6.0-8.0. The maximal Cu(II) adsorption capacity of sample Af and Gf reached 50.97 and 46.08mg/g respectively. The optimum pH for Cr(VI) adsorption was 6.0, and the maximal adsorption capacity reached 51.32 and 59.57mg/g. The Langmuir isotherm can better describe the adsorption behavior of Cr(VI). Coagulation performance of the iron oxyhydrosulfate (Sh) has been significantly enhanced by polysilicic acid (PSA), which was mainly determined by PSA/Sh ratio, pH and coagulant dosage. Coagulation efficiency maintained approximately at 98% when the PSA/Sh ratio ranged from 0.4/0.1 to 1.0/0.1. Polysilicic acid worked efficiently in wide pH range extending, from 2 to 3.5. Coagulation performance improved significantly with the increasing of the coagulant dosage at lower dosage range, while, at higher dosage range, the improvement was not evident even with more coagulant addition.
authors.affiliation: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China.
authors.forename: Min
authors.initials: M
authors.lastname: Gan
authors.affiliation: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China.
authors.forename: Zibo
authors.initials: Z
authors.lastname: Song
authors.affiliation: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China.
authors.forename: Shiqi
authors.initials: S
authors.lastname: Jie
authors.affiliation: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China. Electronic address: zhujy@mail.csu.edu.cn.
authors.forename: Jianyu
authors.initials: J
authors.lastname: Zhu
authors.affiliation: Graduate School, Hunan Agricultural University, Changsha 410083, China.
authors.forename: Yaowu
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: School of Minerals Processing and Bioengineering, Key Laboratory of Biometallurgy of Ministry of Education, Central South University, Changsha 410083, China.
authors.forename: Xinxing
authors.initials: X
authors.lastname: Liu
mesh_terms: D042763:Acidithiobacillus / Q000378:metabolism*; D000327:Adsorption; D052918:Environmental Restoration and Remediation; D005290:Ferric Compounds / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D005427:Flocculation; D058085:Iron Compounds / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D013431:Sulfates / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D005290:Ferric Compounds; D058085:Iron Compounds; D013431:Sulfates; C492331:jarosite; C511969:schwertmannite
keywords: Adsorption; Biosynthesis; Coagulation; Heavy metals; Iron oxyhydrosulfate