Study on cooperative treatment of natural gas pipeline cleaning wastewater and membrane module

Abstract

Abstract Membrane module and pigging wastewater are common pollutants in natural gas transmission process. The treatment of these pollutants is difficult. In this paper, ultrasonic (US), persulfate (PS) and ultrasonic coupled persulfate were used to degrade organic matter in natural gas cleaning wastewater. The effects of pH, initial PS concentration, ultrasonic power, PS dosing batch and other factors on chemical oxygen demand (COD) degradation efficiency of pigging wastewater were investigated. The experimental results show that the optimal treatment effect can be obtained when the dosage of sodium PS is 80g/L, pH=4, the dosing number is 5, and the ultrasonic power is 840 W. After 6 h of reaction, the removal rate of COD can reach 80.08 %. Considering the synergistic treatment of the ultrasonic coupling PS on the solid-liquid pollutant, we adjust the ultrasonic power to 55W (frequency is 40kHz), pH=4.5, dosing twice (total dosage 150mg/L), and the final COD concentration below 100mg/L. However, when pre-ultrasonic activated persulfate in clear water, COD removal rate can reach 95.35 %, which can meet the effluent requirements.