Adsorption of anion polyacrylamide from aqueous solution by polytetrafluoroethylene (PTFE) membrane as an adsorbent: Kinetic and isotherm studies

Efficiencies and mechanisms of the chemical cleaning of fouled polytetrafluoroethylene (PTFE) membranes during the microfiltration of alkali/surfactant/polymer flooding oilfield wastewater

“…Before observing the membrane sample, a conductive layer of gold, of approximately 2 nm thickness, was plated on the membrane surface by sputtering (Gatan, USA). 1 The functional groups on PTFE membranes were observed by Fourier transform infrared spectroscopy (FTIR, Nicolet 560, Thermo Electron Corp., USA), and the measured wavenumber range was 4000-650 cm À1 . 34…”

“…Furthermore, the effects of cleaning sequence (NaClO + NaOH-HCl or HCl-NaClO + NaOH), temperature (20-50 C), and time (0.5-5 h) on the cleaning efficiencies were also investigated. Aer each cleaning cycle, deionized water was ltered again to determine the ux recovery (FR); the calculation process used is shown in eqn (1).…”

“…In recent decades, alkali/surfactant/polymer (ASP) ooding oileld wastewater is being increasingly produced during the oil recovery process. [1][2][3] This wastewater needs to be processed prior to getting discharged into the environment to avoid the risk of severe pollution caused by its organic and inorganic components. 1 Many countries that possess oilelds are seeking efficient and cost effective methods to manage this wastewater.…”

“…[1][2][3] This wastewater needs to be processed prior to getting discharged into the environment to avoid the risk of severe pollution caused by its organic and inorganic components. 1 Many countries that possess oilelds are seeking efficient and cost effective methods to manage this wastewater. 4,5 In some oilelds, conventional techniques have been used to treat the wastewater; however, the emulsied and soluble oils in the wastewater cannot be effectively disposed.…”

“…Thus, it is preferred for ASP ooding oileld wastewater treatment. 1,2,[10][11][12] However, one of the obstacles impeding the large-scale development of MF is membrane fouling, which accounts for the decrease in membrane permeability or a rise in membrane resistance, resulting in the increase in operation costs and cleaning frequency. 13 Although many methods have been adopted to prevent and alleviate membrane fouling, it remains inevitable during the MF process.…”