Synthesis Of Cationic Flocculant And Study Of Micro-sand Enhanced Flocculation Technology To Treat Oilfield Sewage

Aiming at the problems that the development of oilfield produces large amount of sewage which contaminated the environment badly, this paper introduced indoor analysis and test methods to measure various components in oilfield sewage. And the sewage form three sewage treatment station in Yanchang oilfield was analysiszed. Based on two surfactants, white oil, water-soluble nonionic monomers and alcohol were used to form a kind of microemulsion. Flocculant was synthesized by the way of microemulsion synthesis using AM and DMDAAC as monomers and then the type and dosage of initiator, reacting temperature and time was studied to know their influence to the molecule weight of the flocculant. Optimal synthesizing condition was then achieved.The flocculant synthesized by invert microemulsion method was evaluated using the sewage from Yanchang Yongning station. In the evaluating process, floc size, tubidity and COD removing rate were used as evaluation index. Experimental results showed that the flocculant synthesized by invert microemulsion method performed better than flocculant synthesized by conventional method.Afterwards, accompanying with synthesized flocculant the flocculating performance was enhanced by micro-sand technique and then studied. The factors that influencing flocculating performance were ranked by orthogonal experiment analysis. Experimental results indicated that the ranking of main factors that influencing flocculating performance is: dosage of floccutant, size of micro-sand, micro-sand dosage and pH. The single factor analytic approach was used to analyze the influence law of each factor and then optimal condition was achieved. Experimental results showed that the content and median particle size of suspending solid in sewage can meet the standard of reinjection after treatment of optimal condition.