Heavy metal wastewater treatment in RO water treatment system

RO technology has been applied in the treatment of heavy metal wastewater earlier, and a lot of research has been done at home and abroad. As early as the 1970s, RO technology has been applied in the treatment of electroplating wastewater, mainly for the treatment of nickel plating, chromium, zinc rinsing water and mixed heavy metal wastewater.

MohsenNiaa added Na2EDTA to chelate Cu2+ and Ni2+ ions, and then filtered through RO, the ion rejection rate of Cu2+ and Ni2+ can be increased to 99.5%. Covarrubias, Bo-dalo, etc. used RO membrane to treat tannery wastewater, and the results showed that RO membrane had a high removal rate of chromium and organic matter in leather industry wastewater.

Changsha Liyuan New Materials Co., Ltd. uses membrane separation technology to concentrate electroplating nickel rinsing water, and the retention rate of nickel ions is greater than 99%. After one-stage nanofiltration and two-stage RO concentration, the concentration of nickel ions in the concentrated solution reaches 50g·L- 1. The permeate can be reused after treatment. Zhang Liankai adjusted the pH of the heavy metal wastewater generated in the pickling workshop of printed circuit boards to neutrality, and then used the ultrafiltration + RO process to conduct the pilot test. The removal rate of Cu2+ and total dissolved solids by the RO system was 99.9% and 98.9%, respectively.