title: Oil-water separation property of polymer-contained wastewater from polymer-flooding oilfields in Bohai Bay, China.
abstract: In this study, the effects of gravitational settling time, temperature, speed and time of centrifugation, flocculant type and dosage, bubble size and gas amount were investigated. The results show that the simple increase in settling time and temperature is of no use for oil-water separation of the three wastewater samples. As far as oil-water separation efficiency is concerned, increasing centrifugal speed and centrifugal time is highly effective for L sample, and has a certain effect on J sample, but is not valid for S sample. The flocculants are highly effective for S and L samples, and the oil-water separation efficiency increases with an increase in the concentration of inorganic cationic flocculants. There exist critical reagent concentrations for the organic cationic and the nonionic flocculants, wherein a higher or lower concentration of flocculant would cause a decrease in the treatment efficiency. Flotation is an effective approach for oil-water separation of polymer-contained wastewater from the three oilfields. The oil-water separation efficiency can be enhanced by increasing floatation agent concentration, flotation time and gas amount, and by decreasing bubble size.
authors.affiliation: a State Key Laboratory of Oil & Gas Reservoir Geology and Exploitation Engineering , Southwest Petroleum University , Sichuan , Chengdu 610500 , People's Republic of China.
authors.forename: Hua-xing
authors.initials: HX
authors.lastname: Chen
authors.forename: Hong-ming
authors.initials: HM
authors.lastname: Tang
authors.forename: Ming
authors.initials: M
authors.lastname: Duan
authors.forename: Yi-gang
authors.initials: YG
authors.lastname: Liu
authors.forename: Min
authors.initials: M
authors.lastname: Liu
authors.forename: Feng
authors.initials: F
authors.lastname: Zhao
mesh_terms: D002498:Centrifugation; D002681:China; D005427:Flocculation; D006358:Hot Temperature; D009821:Oils / Q000302:isolation & purification*; D010578:Petroleum; D059392:Petroleum Pollution / Q000517:prevention & control; D011108:Polymers / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000737:chemistry*
chemical_list: D009821:Oils; D010578:Petroleum; D011108:Polymers; D062065:Wastewater
keywords: offshore oilfield; oil–water separation; polymer flooding; polymer-contained wastewater; transmittance