Pilot study on treating with the micro-alkalized makeup water of recirculated cooling water system by an integrated membrane process

摘要

In the pilot-scale study, a kind of pretreated wastewater from the pickling process in a steel wire rope manufacturer was reused by a novel integrated membrane process (Reverse osmosis and R-HCO3 anion-exchange resin combined in series), and the operating parameters for the system had been optimized. After the pretreatment process through neutralization, coagulation, clarification sand filtration, and ultra-filtration in sequence, the wastewater was treated with the integrated membrane process. The integrated membrane process can remove most of inorganic and organic ions and realize the micro-alikalization for product water, which can facilitate the zero liquid discharge for cooling water system. Furthermore, the operating parameters of this process were optimized as well: when the pH of inlet water was 8.57, the dosage of scale inhibitor agent was 2.5mg/L, the optimized operating trans-membrane pressure was 1.32MPa, the flux was 39.87 L/(m(2)h), and water recovery rate was 55%. The filtering flow of the resin bed was 20-30m/h, and the regeneration agent (0.7mol/L NaHCO3) consumption ratio is 3.2.