title: Bacteria-assisted preparation of nano α-Fe2O3 red pigment powders from waste ferrous sulfate.
abstract: Massive ferrous sulfate with excess sulfuric acid is produced in titanium dioxide industry each year, ending up stockpiled or in landfills as solid waste, which is hazardous to environment and in urgent demand to be recycled. In this study, waste ferrous sulfate was used as a second raw material to synthesize nano α-Fe2O3 red pigment powders with a bacteria-assisted oxidation process by Acidithiobacillus ferrooxidans. The synthesis route, mainly consisting of bio-oxidation, precipitation and calcination, was investigated by means of titration, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM) and X-ray fluorescence (XRF) to obtain optimum conditions. Under the optimum conditions, nano α-Fe2O3 red pigment powders contained 98.24wt.% of Fe2O3 were successfully prepared, with a morphology of spheroidal and particle size ranged from 22nm to 86nm and averaged at 45nm. Moreover, the resulting product fulfilled ISO 1248-2006, the standards of iron oxide pigments.
authors.affiliation: Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Chuankai
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zeng
authors.affiliation: Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Panyu
authors.initials: P
authors.lastname: Li
authors.affiliation: Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China.
authors.forename: Tonghui
authors.initials: T
authors.lastname: Xie
authors.affiliation: Department of Pharmaceutical & Biological Engineering, School of Chemical Engineering, Sichuan University, Chengdu 610065, PR China. Electronic address: zhangyongkui@scu.edu.cn.
authors.forename: Yongkui
authors.initials: Y
authors.lastname: Zhang
mesh_terms: D042763:Acidithiobacillus / Q000378:metabolism*; D005290:Ferric Compounds / Q000032:analysis* / Q000737:chemistry; D005296:Ferrous Compounds / Q000737:chemistry*; D007220:Industrial Waste; D053758:Nanoparticles / Q000032:analysis* / Q000737:chemistry; D010084:Oxidation-Reduction; D011208:Powders; D012037:Refuse Disposal / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D005296:Ferrous Compounds; D007220:Industrial Waste; D011208:Powders; C000499:ferric oxide; C020748:ferrous sulfate
keywords: Acidithiobacillus ferrooxidans; Bio-oxidation; Nano α-Fe(2)O(3); Red pigment; Waste ferrous sulfate