Sun Xuefei, Pan Yang, Shen Chunxiang, Zuo Chengye, Ding Xiaobin, Liu Gongping, Xing Weihong, Jin Wanqin
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, 30 Puzhou Road(S), Nanjing 211816, China.
NanJing Jiusi High-Tech Co., Ltd., 1 Yuansi Road, Nanjing 211000, China.
Membranes (Basel). 2022 Apr 6;12(4):404. doi: 10.3390/membranes12040404.
The removal of volatile organic compounds (VOCs) from wastewater containing nonvolatile salts has become an important and interesting case of the application of the pervaporation (PV) process. The aim of this study was to evaluate the influence of salts on the PV removal of ethyl acetate from wastewater using a polydimethylsiloxane (PDMS) membrane. The fouled membrane was then characterized via scanning electron microscopy-energy-dispersive X-ray analysis (SEM-EDX) to investigate salt permeation. The membrane backflushing process was carried out by periodically flushing the permeate side of the tubular membrane. The results demonstrated that salts (NaCl and CaCl) could permeate through the PDMS membrane and were deposited on the permeate side. The presence of salts in the feed solution caused a slight increase in the membrane selectivity and a decrease in the permeate flux. The flux decreased with increasing salt concentration, and a notable effect occurred at higher feed-salt concentrations. A permeate flux of up to 98.3% of the original flux was recovered when the permeation time and backflushing duration were 30 and 5 min, respectively, indicating that the effect of salt deposition on flux reduction could be mitigated. Real, organic, saline wastewater was treated in a pilot plant, which further verified the feasibility of wastewater PV treatment.
从含有非挥发性盐的废水中去除挥发性有机化合物（VOCs）已成为渗透蒸发（PV）工艺应用中一个重要且有趣的案例。本研究的目的是评估盐对使用聚二甲基硅氧烷（PDMS）膜从废水中渗透蒸发去除乙酸乙酯的影响。然后通过扫描电子显微镜 - 能量色散X射线分析（SEM - EDX）对污染的膜进行表征，以研究盐的渗透情况。膜的反冲洗过程是通过定期冲洗管式膜的渗透侧来进行的。结果表明，盐（NaCl和CaCl）能够透过PDMS膜并沉积在渗透侧。进料溶液中盐的存在导致膜的选择性略有增加，渗透通量降低。通量随盐浓度的增加而降低，在较高的进料盐浓度下会出现显著影响。当渗透时间和反冲洗持续时间分别为30分钟和5分钟时，可恢复高达原始通量98.3%的渗透通量，这表明盐沉积对通量降低的影响可以得到缓解。在中试装置中对实际的有机含盐废水进行了处理，进一步验证了废水PV处理的可行性。
