Treatment of produced polymer-containing wastewater at oilfield using airlift ceramic membrane filtration equipment

A novel airlift ceramic membrane filtration equipment was employed to treat the produced polymer-containing wastewater at oilfield. In the process of treatment on the produced polymer-containing wastewater at oilfield by ceramic membrane filtration, the energy consumption was reduced due to the gas-liquid two phase flow in place of monophase flow of liquid. Effects of aeration pore size, aeration rate and transmembrane pressure on membrane flux were investigated. It showed that the microporous aeration promoted the more homogeneous distribution of gas inside membrane tube, hence inhibited membrane contamination and concentration polarization and the alleviated decay of membrane flux. The maximum flux was achieved under condition of 1 μm of aeration pore size, of which the membrane flux increased remarkably with an increase in aeration rate from 300 to 600 L·h^-1. Moreover, the transmembrane pressure influenced the membrane flux significantly, with an optimal pressure of 0.4 MPa. The various parameters of quality of the permeated water are stable, which satisfies the requirements of the standard 5.1.1 of reusing water. The energy consumption per ton water of airlift ceramic membrane filtration equipment was also calculated.