title: Flocculation performance and mechanism of graphene oxide for removal of various contaminants from water.
abstract: The application of nanomaterials in water treatment plants has attracted significant attention recently. This study investigates the possibility of using graphene oxide (GO) as a novel flocculant to remove contaminants with different surface charges from water, including two particulate ones (kaolin and hematite) and two soluble ones (humic acid (HA) and cationic light yellow 7GL dye (7GL)). The flocculation performances of traditional polyaluminum chloride (PAC) and original graphite were also tested for comparison. Fractal theory was applied to evaluate the floc properties and explore the flocculation mechanism in combination with zeta potential measurements. For negatively charged contaminants, kaolin and HA, GO was observed to remove these contaminants successfully via the sweeping flocculation effect under acidic and neutral conditions. However, GO was less efficient than PAC. For positively charged contaminants, hematite and 7GL, the flocculation performances of GO were significantly improved than those of PAC via patching effect for hematite suspension and charge neutralization effect for 7GL solution. The results highlighted the extensive potential applicability of GO as a suitable flocculant in water treatment.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, School of Chemistry & Chemical Engineering, Nanjing University, Nanjing 210093, PR China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Yang
authors.forename: Han
authors.initials: H
authors.lastname: Yan
authors.forename: Hu
authors.initials: H
authors.lastname: Yang
authors.forename: Haibo
authors.initials: H
authors.lastname: Li
authors.forename: Aimin
authors.initials: A
authors.lastname: Li
authors.forename: Rongshi
authors.initials: R
authors.lastname: Cheng
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry; D005374:Filtration; D005427:Flocculation; D006108:Graphite / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007616:Kaolin / Q000737:chemistry; D012996:Solutions; D055672:Static Electricity; D014865:Waste Disposal, Fluid; D062065:Wastewater / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification
chemical_list: D000536:Aluminum Hydroxide; D006108:Graphite; D007616:Kaolin; D012996:Solutions; D062065:Wastewater; D014874:Water Pollutants, Chemical; C016213:aluminum oxychloride