title: Effect of viscosity, basicity and organic content of composite flocculant on the decolorization performance and mechanism for reactive dyeing wastewater.
abstract: A coagulation/flocculation process using the composite flocculant polyaluminum chloride-epichlorohydrin dimethylamine (PAC-EPI-DMA) was employed for the treatment of an anionic azo dye (Reactive Brilliant Red K-2BP dye). The effect of viscosity (eta), basicity (B = [OH]/[Al]) and organic content (W(P)) on the flocculation performance as well as the mechanism of PAC-EPI-DMA flocculant were investigated. The eta was the key factor affecting the dye removal efficiency of PAC-EPI-DMA. PAC-EPI-DMA with an intermediate eta (2400 mPa x sec) gave higher decolorization efficiency by adsorption bridging and charge neutralization due to the co-effect of PAC and EPI-DMA polymers. The W(P) of the composite flocculant was a minor important factor for the flocculation. The adsorption bridging of PAC-EPI-DMA with eta of 300 or 4300 mPa x sec played an important role with the increase of W(P), whereas the charge neutralization of them was weaker with the increase of W(P). There was interaction between W(P) and B on the removal of reactive dye. The composite flocculant with intermediate viscosity and organic content was effective for the treatment of reactive dyeing wastewater, which could achieve high reactive dye removal efficiency with low organic dosage.
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China. 53wyf@163.com
authors.forename: Yuanfang
authors.initials: Y
authors.lastname: Wang
authors.forename: Baoyu
authors.initials: B
authors.lastname: Gao
authors.forename: Qinyan
authors.initials: Q
authors.lastname: Yue
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry* / Q000302:isolation & purification; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D011108:Polymers / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D014783:Viscosity; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D011108:Polymers; D000644:Quaternary Ammonium Compounds; D014874:Water Pollutants, Chemical; C551304:polyepichlorohydrin-dimethylamine; C525123:reactive brilliant red K-BP; C016213:aluminum oxychloride; D000536:Aluminum Hydroxide