title: Titanium tetrachloride for silver nanoparticle-humic acid composite contaminant removal in coagulation-ultrafiltration hybrid process: floc property and membrane fouling.
abstract: Titanium-based coagulation is expected to achieve both efficient water purification and sludge recycling. This study is the first attempt to use titanium tetrachloride (TiCl4) for silver nanoparticle (AgNP)-humic acid composite contaminant removal in a coagulation-ultrafiltration (C-UF) process, where characterization of flocs and membrane fouling under varied coagulant dose, initial solution pH, and AgNP concentration conditions are the main contents. Results suggested that the TiCl4achieved high AgNP removal in the form of silver nanoparticle through adsorption and sweep flocculation and simultaneously exerted additional 68.2 % higher dissolved organic carbon removal than Al2(SO4)3. The TiCl4produced larger and stronger flocs but with weaker recoverability and less compact degree than did Al2(SO4)3. Floc properties were independent of AgNP concentration except floc fractal dimension, which was negatively correlated with AgNP concentration. The TiCl4precoagulation caused less membrane fouling within wider pH range than Al2(SO4)3did in the C-UF process. Incorporation of AgNPs during the TiCl4pretreatment process facilitated the mitigation of membrane fouling, which was, however, negligibly influenced by AgNP concentration in the case of Al2(SO4)3.
authors: Department of Civil Engineering, Faculty of Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.|Key Laboratory for Special Functional Aggregated Materials of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
authors: Yanxia
authors: Y
authors: Zhao
authors: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No.27 Shanda South Road, Jinan, 250100, People's Republic of China.
authors: Yangyang
authors: Y
authors: Sun
authors: School of Environmental Science and Engineering, Qilu University of Technology, Jinan, 250353, China.
authors: Chang
authors: C
authors: Tian
authors: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No.27 Shanda South Road, Jinan, 250100, People's Republic of China.
authors: Baoyu
authors: B
authors: Gao
authors: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, No.27 Shanda South Road, Jinan, 250100, People's Republic of China. wangyan_sdjn@aliyun.com.
authors: Yan
authors: Y
authors: Wang
authors: Centre for Technology in Water and Wastewater, School of Civil and Environmental Engineering, University of Technology, (UTS), P.O. Box 123, Broadway, Sydney, NSW, 2007, Australia.
authors: Hokyong
authors: H
authors: Shon
authors: Key Laboratory for Special Functional Aggregated Materials of Education Ministry, School of Chemistry and Chemical Engineering, Shandong University, Jinan, 250100, China.
authors: Yanzhao
authors: Y
authors: Yang
mesh_terms: D005427:Flocculation; D006812:Humic Substances / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000032:analysis*; D012834:Silver / Q000032:analysis*; D012996:Solutions; D014025:Titanium / Q000737:chemistry*; D014462:Ultrafiltration; D014873:Water Pollutants / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
chemical_list: D006812:Humic Substances; D008567:Membranes, Artificial; D012996:Solutions; D014873:Water Pollutants; D012834:Silver; C025096:titanium tetrachloride; D014025:Titanium
keywords: Coagulation-ultrafiltration; Floc characteristics; Membrane fouling; Silver nanoparticles; Titanium tetrachloride