Biofouling Removal from Membranes Using Nonthermal Plasma

An essential aspect of wastewater treatment systems based on membranes is fouling, which leads to a decrease in their performance and durability. The membrane biofouling is directly related to the deposition of biological particles (e.g., microorganisms in the form of biofilm) on the membrane surface. The objective of the study was to investigate the possibility of using nonthermal plasma for membrane treatment to overcome the biofouling problem. The removal of biological cells from the membrane surface was performed in a dielectric barrier discharge (DBD) plasma. The biofoulant (i.e., activated sludge) on the surface of membranes was treated with plasma for 3-10 min, corresponding to a plasma dose of 13-42 J cm(-2). Results of biofouling removal studies indicated that the process was very efficient (i.e., lethal effect was also observed) and dependent on the type of membrane and exposure time to the nonthermal plasma. Moreover, investigations of the influence of plasma treatment on extracellular polymeric substances of biofilms have confirmed the possibility of using plasma in the process of protein release from biological structures, which results in their destruction. It seems that plasma technologies can be part of the so-called hybrid methods of removing biological contamination of membranes used in wastewater treatment.