Study on the Influencing Factor of Zeta Potential and Treating Conditions for Polymer-Flooded Oily Waste Water

The influence of oil content, solid suspend (SS) content and polymer concentration on zeta potential of polymer containing waste water has been studied. The result shows that with the increasing in polymer content, the zeta potential absolute value of charged particles, increase and the average relative displacement of charged particles changed obviously. With the increasing in oil content and solid suspend content have no great influence on zeta potential of charged particles and average relative displacement of charged particles. The result shows that polymer content is the main reason influencing the stability of polymer-flooded oily waste water. The zeta potential of wastewater has been determinated under different stirring rate and different dosage of coagulate flocculating agent. The results show that when the stirring rate is 300 r/min and coagulate flocculating agent BHQ-08 is 100 mg/L, the oil removal efficiency of polymer flooded wastewater is the highest in simulation and on-site polymer flooding, being 64.2% and 70.9% respectively. The absolute values of zeta potential for simulation and on-site polymer flooding decrease by 12.51% and 19.65% respectively. When the stirring rate is 300 r/min and coagulate flocculating agent BHQ-08 is 250 mg/L, absolute value of zeta potential decrease to the lowest, being 33.19 mV, with the best flocculating and aggregating effect, and the oil removal effect is also the best. The study results provide technical reference for processing wastewater containing polymers in oilfield polymer flooding.