title: Treatment of aging oily wastewater by demulsification/flocculation.
abstract: The aging oily wastewater (AOW) from Tarim oilfield in China was treated by demulsification/flocculation. A novel sewage treatment agent (YL-7) was developed using a cationic surfactant (LY) and flocculants (polydimethyl diallyl ammonium chloride (PDMDAAC)/polyaluminum chloride (PAC)). At an YL-7 dosage of 320 mg L(-1) at 323 K for 90 min, the oil content of AOW was reduced from 728.8 mg L(-1) to 23.7 mg L(-1), and oil removal efficiency reached 96.7%. Microorganism flocs (extracted from AOW) with high negative zeta potential enhanced the stability of oil/water emulsion. LY and PDMDAAC neutralized the negative charge on the oil droplet surface. PDMDAAC and PAC mainly bridged and swept flocs during the flocculation process. YL-7 was found to be a suitable sewage treatment agent in removing oil from AOW.
authors.affiliation: a School of Chemical Engineering, East China University of Science and Technology , Shanghai , P.R. China.
authors.forename: Jing Y
authors.initials: JY
authors.lastname: Yang
authors.affiliation: a School of Chemical Engineering, East China University of Science and Technology , Shanghai , P.R. China.
authors.forename: Liang
authors.initials: L
authors.lastname: Yan
authors.affiliation: a School of Chemical Engineering, East China University of Science and Technology , Shanghai , P.R. China.
authors.forename: Shao P
authors.initials: SP
authors.lastname: Li
authors.affiliation: a School of Chemical Engineering, East China University of Science and Technology , Shanghai , P.R. China.
authors.forename: Xin R
authors.initials: XR
authors.lastname: Xu
mesh_terms: D000536:Aluminum Hydroxide / Q000737:chemistry*; D002681:China; D052918:Environmental Restoration and Remediation / Q000379:methods*; D005427:Flocculation; D006863:Hydrogen-Ion Concentration; D061329:Oil and Gas Fields / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D000536:Aluminum Hydroxide; D062065:Wastewater; D014874:Water Pollutants, Chemical
keywords: Aging oily wastewater; flocculation; microorganism flocs; zeta potential