Abstract
Residual anionic polyacrylamide in polymer-flooding oil production wastewater results in the formation of a thermodynamically stable system. In this study, the effects of three different types of medicaments, namely, cationic, anionic and nonionic agents, in dynamic treatments, such as adding a position, dosage and combined processes of chemical addition, on the oil removal rate of sewage were examined. In the treatment with a single agent, the oil removal rate of the cationic agent CQY-1 and the nonionic agent CHF-2 was ≥ 97.8%. The charge characteristics of different ionic agents for the combined dosing treatment indicated that the oil removal rate was better than that of a single agent; the combined dosing ratio was 50 mg/L CHP-1 and 50 mg/L CHP-2. At 80 mg/L CQY-1, the oil removal rate of the dynamic process was ≥ 98.8%, and the dosage of CQY-1 was reduced from 200 mg/L to 50–150 mg/L, which corresponded to a decrease of 25.0%–75.0%. Therefore, the combined dosing process effectively reduced the single dosage.