Effects of hydrogen peroxide, temperature and treatment time on degradation properties of polyethersulfone ultrafiltration membrane

Abstract

Oxidative cleaning agents such as hydrogen peroxide $(H_2 O_2 )$ and sodium hypochlorite (NaClO) used in water and wastewater treatment play an important role in the degradation and rapid aging of the polymeric membranes. In addition, when the temperature is above the maximum operating range of the membrane, it negatively affects the membrane performance.$H_2 O_2 $ ,which is also known as a green and environmentally friendly strong oxidant because of releasing only water as a by-product, can provide good cleaning efficiency under temperature, but its influence on membrane aging is not fully understood. In this study, the aging of polyethersulfone (PES) ultrafiltration (UF) membrane using $H_2 O_2 $ under high-temperature conditions and degradation of the polymeric membrane were systematically investigated using response surface methodology (RSM). The effects of $H_2 O_2 $ concentration, temperature, and treatment time were tested on membrane flux, contact angle, pore size, and porosity for decomposed membrane. The results showed that normalized permeability was significantly changed approximately 2.34-folds by $H_2 O_2 $ concentration at an exposure dose of 5 mM and 373 K temperature. Moreover, the largest pore sizes as 161.23 nm and 160.73 nm were obtained at the conditions of 2.5 mM $H_2 O_2 $concentration and 373 K temperature. The lowest contact angle (54.76°) and porosity (61.88%) were obtained at the same conditions. The results depicted that $H_2 O_2 $ can be used for membrane cleaning with minimum membrane degradation at moderate conditions