A feasibility study of industrial wastewater recovery using electrodialysis reversal

摘要

A wastewater reclamation and reuse"mini-plant"was established at the site of China Steel Corporation(CSC)wastewater treatment plant.The purpose of the mini-plant is to demonstrate the technical and economical feasibility of electrodialysis reversal(EDR)process.The mini-plant includes a sand filtration unit and an EDR unit which has a daily treatment capacity of 350 CMD.Raw wastewater had an averaged conductivity of 3860 mu S/cm,pH between 7.7 and 8.3,and COD between 30 and 70 mg/L.When the EDR unit operates at a 75% of water reclamation rate,92% of desalination rate,98% of chlorine ion removal,80% of sulfate removal,99% of calcium ion removal,and 51% of COD removal rate can be achieved.The water quality of product stream is 305 mu S/cm for conductivity,13 mg/L for chlorine ion,86 mg/L for sulfate,1.4 mg/L for calcium ion,and of 20 mg/L for COD concentration.Operation cost of the EDR mini-plant was also estimated in this project.The electricity required for electrodes power supply and pumping is 0.85 kW h per cubic meter of treated water.Total operation cost including electricity fee and chemical cost is about 0.146 per cubic meter of treated water.