Investigation on two integrated membrane systems for the reuse of electroplating wastewater

Abstract

A pilot study was done on a nanofiltration (NF)‐reverse osmosis (RO) and RO‐NF integrated membrane system about the feasibility of membrane for electroplating rinse wastewater treatment in concentrate stage configuration. Nickel sulphate solution was used as a synthetic wastewater. Water recovery, metal rejection and specific entropy production (SEP) were investigated under different operation pressure, feed temperature and feed concentration. The results showed water recovery of RO‐NF system was more than 10% higher than NF‐RO system but the SEP was 14.47% lower than NF‐RO system. The detailed analysis on economic cost and environmental impact of two systems was conducted based on a certain operation condition. Results indicated that the cost of RO‐NF system was 0.46 $/m3, which was lower than NF‐RO system, and the prevention cost of RO‐NF system was 11.46% lower than NF‐RO system. Generally, RO‐NF system was better than NF‐RO system.

Resource utilization of electroplating wastewater: obstacles and solutions

“…The separation efficiency of the RO–NF system has been proved to be higher than that of the NF–RO system. 171…”

“…Membrane fouling is an unavoidable problem with the current integrated membrane technology and is one of the main costs associated with the use of membrane technology in plants, the mechanisms of which are: (1) formation of the filter cake layer; (2) blockage of the membrane pores; (3) adsorption within the membrane pores. 171 The use of integrated membrane technology requires close attention to three aspects: the physical and chemical properties of the membrane itself, the water quality conditions and the operating parameters. Researches have shown that high organic content in water bodies can significantly increase the degree of membrane contamination.…”