Resources recycle of traditional Chinese medicine (TCM) wastewater 1 : Effectiveness of the UF-MD hybrid system and MD process optimization

TCM wastewater treatment is a significant environmental issue in China. This study investigated the effectiveness of the UF-MD hybrid system on recycling valuable resources in TCM wastewater. Synthetic TCM wastewater was prepared and separated with the self-assemble UF-MD hybrid system. Moreover, the feed temperature (45 °C, 55 °C, 65 °C) and membrane materials' influence on MD performance were also evaluated. Results show that the UF-MD hybrid system is efficient to achieve a complete separation and resources recycle from the TCM wastewater. The MD flux production increased with the increment of feed temperature. However, some bioactive compounds could not be concentrated in MD due to their potential degradation at high temperatures, and membrane wetting might be an issue in long-term operation. Although PP membranes exhibited the highest flux among PP, PTFE and PVDF membranes, considering the wetting and fouling resistance, PTFE membranes would be a better option for long-term MD operation at 65 °C.