title: Synthesis, characterization, and secondary sludge dewatering performance of a novel combined silicon-aluminum-iron-starch flocculant.
abstract: Flocculation is one of the most widely used cost-effective pretreatment method for sludge dewatering, and a novel environmentally friendly and efficient flocculant is highly desired in the sludge dewatering field. In this study, a novel combined silicon-aluminum-ferric-starch was synthesized by grafting silicon, aluminum, and iron onto a starch backbone. The synthesized starch flocculant was characterized using Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy, X-ray powder diffraction, and thermogravimetric analysis. The dewatering performance of secondary sludge was evaluated according to the capillary suction time, settling volume percentage, and specific resistance to filtration. The results indicated that the copolymer exhibited: (1) a good dewatering efficiency over a wide pH range of 3.0-11.0, (2) superior sludge dewatering performance compared to those of polyaluminum chloride (PACl), polyacrylamide (PAM), ferric chloride, and (3) a discontinuous surface with many channels or voids that helps to mobilize the impermeable thin layer of secondary sludge during filter pressing. Such a novel copolymer is a promising green flocculant for secondary sludge dewatering applications.
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China. Electronic address: qintlin@163.com.
authors.forename: Qintie
authors.initials: Q
authors.lastname: Lin
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
authors.forename: Huanlong
authors.initials: H
authors.lastname: Peng
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
authors.forename: Songxiong
authors.initials: S
authors.lastname: Zhong
authors.affiliation: School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, PR China.
authors.forename: Jiangxin
authors.initials: J
authors.lastname: Xiang
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D033362:Powder Diffraction; D012722:Sewage / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013213:Starch / Q000737:chemistry*; D013818:Thermogravimetry; D014865:Waste Disposal, Fluid / Q000379:methods; D014867:Water / Q000737:chemistry; D014961:X-Ray Diffraction
chemical_list: D012722:Sewage; D014867:Water; D013213:Starch; D000535:Aluminum; D007501:Iron; D012825:Silicon
keywords: Flocculant; Grafting synthesis; Sludge dewatering; Starch