title: Recycling of iron and silicon from drinking water treatment sludge for synthesis of magnetic iron oxide@SiO₂ composites.
abstract: More attention has been paid to the deterioration of water bodies polluted by drinking water treatment sludge (DWTS) in recent years. It is important to develop methods to effectively treat DWTS by avoiding secondary pollution. We report herein a novel investigation for recovery of Si and Fe from DWTS, which are used for the synthesis of two iron oxide@SiO2 composites for adsorption of reactive red X-3B (RRX-3B) and NaNO2. The results show that Fe(3+) (acid-leaching) and Si(4+) (basic-leaching) can be successfully recovered from roasted DWTS. Whether to dissolve Fe(OH)3 precipitation is the key point for obtaining Fe3O4 or γ-Fe2O3 particles using the solvothermal method. The magnetic characteristics of Fe3O4@SiO2 (390.0 m(2) g(-1)) or Fe2O3@SiO2 (220.9 m(2) g(-1)) are slightly influenced by the coated porous SiO2 layer. Peaks of Fe-O stretching vibration (580 cm(-1)) and asymmetric Si-O-Si stretching vibrations (1080 cm(-1)) of Fe3O4@SiO2 indicate the successful coating of a thin silica layer (20-150 nm). The adsorption capacity of RRX-3B and NaNO2 by Fe3O4@SiO2 is better than that of Fe2O3@SiO2, and both composites can be recycled through an external magnetic field. This method is an efficient and environmentally friendly method for recycling DWTS.
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China.|Key Laboratory of Chemical Engineering Process and Technology for High-Efficiency Conversion, College of Heilongjiang Province, Heilongjiang University, Harbin, 150080, China.
authors.forename: Lingyou
authors.initials: L
authors.lastname: Meng
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China.
authors.forename: Yingzi
authors.initials: Y
authors.lastname: Chan
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China.
authors.forename: Han
authors.initials: H
authors.lastname: Wang
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China. hlju_chem226@163.com.|School of Civil Engineering, Heilongjiang Institute of Technology, Harbin, 150050, China. hlju_chem226@163.com.
authors.forename: Ying
authors.initials: Y
authors.lastname: Dai
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China, School of Chemistry and Materials Science, Heilongjiang University, Harbin, 150080, China. zoujinlong@aliyun.com.|Key Laboratory of Chemical Engineering Process and Technology for High-Efficiency Conversion, College of Heilongjiang Province, Heilongjiang University, Harbin, 150080, China. zoujinlong@aliyun.com.
authors.forename: Jinlong
authors.initials: J
authors.lastname: Zou
mesh_terms: D000327:Adsorption; D005290:Ferric Compounds / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D059027:Recycling; D012722:Sewage / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D005290:Ferric Compounds; D012722:Sewage; C000499:ferric oxide; D012822:Silicon Dioxide; D007501:Iron; D012825:Silicon
keywords: Adsorption; Drinking water treatment sludge; Extraction; Magnetic composite; Recycling