Biofouling Removal from Membranes Using Nonthermal Plasma

Irena Maliszewska,Tomasz Czapka

doi:10.3390/en13174318

Abstract

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.

Highlights

The issue of water purity is urgent because of its impact on the ecosystem as well as human and animal health
It seems that plasma technologies can be part of the so-called hybrid methods of removing biological contamination of membranes used in wastewater treatment
The purpose of this paper is to present the possibility of using nonthermal plasma for membrane cleaning to overcome the biofouling problem in wastewater treatment

Summary

Introduction

The issue of water purity is urgent because of its impact on the ecosystem as well as human and animal health. Water in the form of wastewater contains significant amounts of harmful compounds (e.g., chemical, biological, heavy metals, etc.), and needs to be treated to improve its quality to the required safety level. Water management is becoming increasingly challenging and several wastewater treatment methods have emerged in recent decades [1]. The separation of materials through a membrane depends on pore and molecule size, and water treatment procedures use different types of membranes [2]. The hydrophobicity of membranes is a disadvantage contributing to their fouling. Membrane fouling is triggered by deposition and accumulation of inorganic and organic molecules (i.e., microbial cells) on the filter membrane resulting in complete blocking of the pores [5]. Biofouling is a comprehensive, dynamic, and fairly slow process involving various biological mechanisms that have not been fully understood yet [6,7]

Objectives

Methods

Results

Conclusion