Abstract: ?Iron-carbon micro-electrolysis process is proposed for efficient treatment of drilling wastewater in the oil and gas extraction industry. ?Single-factor experiments were conducted to systematically investigate the effects of initial pH, iron-carbon ratio, aeration rate, and reaction time on COD removal rate and color removal rate. On this basis, a quadratic polynomial regression model was established with COD removal rate and color removal rate as response variables, followed by analysis of variance (ANOVA) and residual normality testing, and finally multi-objective optimization was performed using the satisfaction function method. The results show that the optimal operating parameters for treating drilling wastewater by the micro-electrolysis process are an initial pH of 3.5, an iron-carbon ratio of 2.4, an aeration volume of 0.91L/min and a reaction time of 46 min. At this time, the COD and color removal rates predicted by the model can reach 90.6% and 94.1% respectively. The research results can provide a theoretical basis for the harmless treatment of drilling wastewater.

Key words: drilling wastewater, micro-electrolysis, central composite design, COD, chromaticity