An Electrocatalytic Membrane Reactor with Self‐Cleaning Function for Industrial Wastewater Treatment

Abstract

Industrial wastewater has become a global issue due to its high concentration of pollutants, especially refractory organic compounds. Membrane technology has attracted considerable attention in industrial wastewater purification over the past decades owing to its high flexibility regarding water quality and low investment costs. However, inherent membrane fouling caused by concentration polarization and pore blocking leads to low plant reliability and limits wide industrial application in wastewater treatment. Controlling and mitigating membrane fouling has become the most critical problem in the field of membrane technology for water and wastewater treatment. To tackle this challenging issue, many strategies have been implemented, such as pretreating feed water, development of antifouling membranes, new design of membrane modules, optimizing operating conditions, and integrating membrane processes with other techniques. Despite all the efforts, membrane fouling is still not completely solved. Apart from membrane technology, photocatalytic oxidation and electrocatalytic oxidation, with their low toxicity and high efficiency, have been considered competitive candidates for industrial wastewater treatment. However, low utilization of visible-light photons and difficult recycling of photocatalysts for photocatalytic oxidation, as well as the huge energy consumption for electrocatalytic oxidation, hinder their extensive application. Besides, their combination with membrane technology is still far from satisfactory for water treatment. To solve the challenging problem of membrane fouling in industrial water treatment, we propose a simple strategy that could avoid membrane fouling completely. We present the design of a novel electrocatalytic membrane reactor (ECMR) with self-cleaning function (Figure 1). In the reactor, a tubular conductive membrane as anode and a stainless steel tube surrounding the membrane as cathode were connected by a dc regulated power supply (Figure S1 in the Supporting Information). During the treatment, the wastewater permeates through the membrane from the outside in by means of a suck pump operating in a dead-end manner and the “clean” water is obtained from the inside.