Regeneration of granular activated carbon by an electrochemical process

An electrochemical (EC) process was used to investigate the effectiveness of regeneration of field-spent granular activated carbon (SGAC) collected from a wastewater treatment plant. The influences of regeneration parameters such as processing time, voltage gradient, and processing fluid, were performed. The performance of EC regeneration was evaluated via batch methylene blue (MB) adsorption tests. Increasing voltage and prolonging the process would increase the regeneration efficiency (RE). By considering the energy demand, the optimum conditions for a 91.1% RE with an energy cost of 39 US$/ton were: 0.1 M NaCl, 24 h, and 5 V/cm. Compared to thermal, ultrasonic, and base washing regenerations, this EC process is effective and economic viable for GAC regeneration.