Trends in Decreasing Disinfection By-Products Formation during Electrochemical Technologies
Djamel Ghernaout, Noureddine Elboughdiri, Abdulaziz Alghamdi, Badia Ghernaout
Abstract
Disinfecting water and wastewater electrochemically is a cost-effective and environmentally friendly alternative for the chemical disinfection. During electrochemical disinfection, the water is passed through an electrolytic cell which is equipped with a set of electrodes. The effectiveness of the process depends upon cell configuration, electrode material, electrolyte composition, microorganism, water flow rate, and current density. One of the main advantages of electrodisinfection is the on-site production of disinfectants; thereby the common drawbacks of chlorination including transportation and storage of hazardous chemicals can be avoided. On the other hand, the high cell voltages due to low electrical conductivity of water and the high capital cost are the main bottlenecks for electrodisinfection. The generation of chlorinated by-products stays the main worry related to electrochemical water treatment processes. This work discusses the main tendencies in dealing with such issues. In some setups, the electrolyte separates the anode and cathode is a proton exchange membrane. This assists to reduce the formation of perchlorate and such conduct is improved in the smallest cell for which the so short contact periods between the electrodes and the water helps to avert the formation of perchlorates when working in a single-pass mode, which becomes a really remarkable point. Other strategies are examined such as developed electrochemical advanced oxidation process, the electroperoxone (E-peroxone) process, which combines ozonation with in situ electro-generation of hydrogen peroxide (H 2 O 2 ) from cathodic oxygen reduction.