An integrated adsorption- and membrane-based system for high-salinity aniline wastewater treatment with zero liquid discharge

Currently, water shortage has been emerged as a severe problem in human life. In this work, a zero liquid discharge technology was proposed combining macroporous resin adsorption and desorption, bipolar membrane electrodialysis (BMED) and electrodialysis (ED). During the process of resin adsorption and desorption, the adsorption capacity of the resin and the concentration of the desorption solution were investigated. In addition, the power supply, volume ratio, membrane type in BMED/ED processes were investigated. According to the results of the study, the eluting agent solution of 4% NaOH was the optimal content, with a desorption rate of 97.49%. In the BMED process, the acid/base concentration reached 1.25 mol/L and 0.85 mol/L, respectively. During ED process, the final concentration of NaOH was 0.14 mol/L, and the COD rejection rate reached 93.3%. In the whole work, the NaOH and the macroporous resin were recycled, which achieved the closed-loop zero liquid discharge of salt recycling and reuse in wastewater. Furthermore, techno-economic analysis (0.79 $/kg, 0.21 $/kg) and water recovery rate calculations (96%, 83%) were carried out for the BMED and ED processes, which demonstrated that the process was promising for industrial application.

Automated summary

This study proposed a zero liquid discharge technology combining macroporous resin adsorption and desorption, bipolar membrane electrodialysis (BMED) and electrodialysis (ED). The results showed promising potential for industrial application with high desorption rate and COD rejection rate, as well as techno-economic analysis.