Water is indispensable for human life and economic development, and therefore, water treatment is one of the primary technical processes essential for people’s living and the overall sectors of the national economy.
Desalination by electrosorption is a novel water treatment technique, which is a combination of electrochemical method and adsorption method of separation. It is employed to purify water by removing salts and other substances dissolved in water by using the adsorption of ions and charged particles in water when an electric field is applied to an electrode made of conductive adsorbent material.
The core of electrosorption technology is the selection of electrode material and the design of electrode structure. Carbon adsorbent materials such as activated carbon, activated carbon fibers, graphene, carbon nanotubes and carbon aerogels are used as electrode material.
Kim Chang Sok, a researcher at the School of Science and Engineering, calculated the desalination rate by electrosorption of activated carbon electrodes from the electrical double layer phenomena at the liquid interface and the characteristics of activated carbon, and investigated the main factors i.e. voltage, interelectrode distance, water flow rate and treatment time, influencing the desalination of groundwater by electrosorption using electrodes. On this basis, he determined the optimum electrosorption conditions.
When the voltage was 2V, the interelectrode distance 15mm, the water flow rate 4m3/(kg·h) and the time 45min, the electrical conductivity and the hardness decreased by 43.8% and 33.5%, respectively.
The results confirmed that water treatment by electrosorption is an effective method with high desalination and softening efficiency, low power consumption and no environmental pollution.