两性清水剂处理聚合物驱含油污水

Treatment of oily wastewater produced from polymer flooding by amphoteric clarifier

关键词:  聚合物驱  含聚污水  两性清水剂  絮凝  油泥 

Key words:  polymer flooding  polymer-containing produced water  amphoteric water clarifier  flocculation  oily sludge

摘要:

聚合物驱含油污水中含有较高浓度的残留聚合物,采用传统的阳离子型清水剂不佳,并产生大量黏性“油泥”,对油田生产造成不利影响。为解决上述问题,研制了一种新型的两性清水剂QS-01。结果 表明,QS-01的ρ(加药)为130 mg/L以上时具有良好的清水除油效果,处理后水体澄清透明,ρ(油)由5 000 mg/L降至45 mg/L以下；QS-01可处理温度范围较宽(50～80 ℃),并具有良好的稳定性；ρ(加药)为150 mg/L条件下进行放大评价实验,处理后的污水ρ(油)为40 mg/L,絮体呈松散状,有良好流动性。机理分析结果表明,两性清水剂可有效破坏油水界面双电层,降低油水界面膜强度,并与残留聚合物间的相互作用大幅减弱,因而有望解决含聚污水处理中的“油泥”问题。 

Abstract:

Owing to residual hydrolyzed polyacrylamide, oily wastewater produced from polymer flooding was difficult to be treated for its high viscosity and emulsified characteristics. Cationic water clarifier, currently used at increased dosages, can destabilize the polymer in oily wastewater, thus resulting with a large quantity of viscous oily sludge. To settle this problem, a novel amphoteric clarifier QS-01 was synthesized. The experiment results showed that:when the water clarifier was dosed at 130 mg/L and above, the treated wastewater was clear and even colorless with the residual oil concentration decreased dramatically from 5 000 mg/L to 45 mg/L; QS-01 exhibited excellent water-clarification effects at a wide range of temperature from 50 ℃ to 80 ℃; in scale-up assessment experiments, QS-01 also showed satisfying performance with the bright and clean resultant aqueous phase, and the flocs with good fluidity and low viscosity. The mechanism analysis revealed that QS-01 could decrease the thickness of the oil-water interface electric double layer and the strength of interfacial film, and thus weaken the electrostatic neutralization interactions between the clarifier and the anionic polymer in wastewater. It indicated that the problem of viscous polymer-containing oily sludge could be avoided by QS-01.