title: Passivation process and the mechanism of packing particles in the Fe0/GAC system during the treatment of ABS resin wastewater.
abstract: This study provides mechanistic insights into the passivation of the packing particles during the treatment of acrylonitrile-butadiene-styrene (ABS) resin wastewater by the Fe0/GAC system. The granular-activated carbon (GAC) and iron chippings (Fe0) were mixed together with a volumetric ratio of 1:1. GAC has a mean particle size of approximately 3-5 mm, a specific surface of 748 m2 g(-1), a total pore volume of 0.48 mL g(-1) and a bulk density of 0.49 g cm(-3). The iron chippings have a compact and non-porous surface morphology. The results show that the packing particles in the Fe0/GAC system would lose their activity because the removal of TOC and PO4(3-) for ABS resin wastewater could not carried out by the Fe0/GAC system after 40 days continuous running. Meanwhile, the availability of O2 and intrinsic reactivity of Fe0 play a key role on the form of passive film with different iron oxidation states. The passive film on the surface of iron chippings was formed by two phases: (a) local corrosion phase (0-20 d) and (b) co-precipitation phase (20-40 d), while that of GAC was mainly formed by the co-precipitation of corrosion products with SO4(2-) and PO4(3-) because SO4(2-) and PO4(3-) would not easily reach the Fe0 surface. Therefore, in order to avoid the occurrence of filler passivation, high concentrations of SO4(2-) and PO4(3-) in wastewater should be removed before the treatment process of the Fe/GAC system.
authors.forename: Bo
authors.initials: B
authors.lastname: Lai
authors.forename: Yuexi
authors.initials: Y
authors.lastname: Zhou
authors.forename: Juling
authors.initials: J
authors.lastname: Wang
authors.forename: Yunhong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zhiqiang
authors.initials: Z
authors.lastname: Chen
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D000181:Acrylonitrile / Q000737:chemistry*; D000327:Adsorption; D002070:Butadienes / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010100:Oxygen / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry*; D020058:Styrene / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry; D013499:Surface Properties; D062065:Wastewater; D014873:Water Pollutants / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*
chemical_list: D000180:Acrylic Resins; D000181:Acrylonitrile; D002070:Butadienes; D002244:Carbon; D007501:Iron; D010100:Oxygen; D010710:Phosphates; D011137:Polystyrenes; D020058:Styrene; D013455:Sulfur; D062065:Wastewater; D014873:Water Pollutants; D014874:Water Pollutants, Chemical; C024636:ABS resin; C031763:1,3-butadiene