Mohanadas Dharshini, Nordin Puteri Mimie Isma, Rohani Rosiah, Dzulkharnien Nur Syafiqah Farhanah, Mohammad Abdul Wahab, Mohamed Abdul Peer, Abu Bakar Suriani
Department of Chemical & Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor, Malaysia.
Research Centre for Sustainable Process Technology, Faculty of Engineering & Built Environment, Universiti Kebangsaan Malaysia, UKM, Bangi 43600, Selangor, Malaysia.
Membranes (Basel). 2022 Dec 29;13(1):46. doi: 10.3390/membranes13010046.
Oily wastewater (OW) is detrimental towards the environment and human health. The complex composition of OW needs an advanced treatment, such as membrane technology. Membrane distillation (MD) gives the highest rejection percentage of pollutants in wastewater, as the membrane only allows the vapor to pass its microporous membrane. However, the commercial membranes on the market are less efficient in treating OW, as they are prone to fouling. Thus, the best membrane must be identified to treat OW effectively. This study tested and compared the separation performance of different membranes, comparing the pressure-driven performance between the membrane filtration and MD. In this study, several ultrafiltration (UF) and nanofiltration (NF) membranes (NFS, NFX, XT, MT, GC and FILMTEC) were tested for their performance in treating OW (100 ppm). The XT and MT membranes (UF membrane) with contact angles of 70.4 ± 0.2° and 69.6 ± 0.26°, respectively, showed the best performance with high flux and oil removal rate. The two membranes were then tested for long-term performance for two hours with 5000 ppm oil concentration using membrane pressure-filtration and MD. The XT membrane displayed a better oil removal percentage of >99%. MD demonstrated a better removal percentage; the flux reduction was high, with average flux reduction of 82% compared to the membrane pressure-filtration method, which experienced a lower flux reduction of 25%. The hydrophilic MT and XT membranes have the tendency to overcome fouling in both methods. However, for the MD method, wetting occurred due to the feed penetrating the membrane pores, causing flux reduction. Therefore, it is important to identify the performance and characteristics of the prepared membrane, including the best membrane treatment method. To ensure that the MD membrane has good anti-fouling and anti-wetting properties, a simple and reliable membrane surface modification technique is required to be explored. The modified dual layer membrane with hydrophobic/hydrophilic properties is expected to produce effective separation in MD for future study.
含油废水（OW）对环境和人类健康有害。含油废水的复杂成分需要先进的处理方法，如膜技术。膜蒸馏（MD）在废水处理中对污染物的截留率最高，因为该膜只允许蒸汽通过其微孔膜。然而，市场上的商用膜在处理含油废水时效率较低，因为它们容易受到污染。因此，必须确定最佳的膜来有效处理含油废水。本研究测试并比较了不同膜的分离性能，比较了膜过滤和膜蒸馏之间的压力驱动性能。在本研究中，测试了几种超滤（UF）和纳滤（NF）膜（NFS、NFX、XT、MT、GC和FILMTEC）处理含油废水（100 ppm）的性能。接触角分别为70.4±0.2°和69.6±0.26°的XT和MT膜（超滤膜）表现出最佳性能，通量和除油率都很高。然后使用膜压滤和膜蒸馏对这两种膜在5000 ppm油浓度下进行了两小时的长期性能测试。XT膜的除油率>99%，表现更好。膜蒸馏的去除率更高；通量降低幅度很大，与膜压滤法相比，平均通量降低82%，而膜压滤法的通量降低幅度较小，为25%。亲水性的MT和XT膜在两种方法中都有克服污染的趋势。然而，对于膜蒸馏方法，由于进料渗透到膜孔中导致了润湿现象，从而造成通量降低。因此，确定所制备膜的性能和特性，包括最佳的膜处理方法非常重要。为确保膜蒸馏膜具有良好的抗污染和抗润湿性能，需要探索一种简单可靠的膜表面改性技术。具有疏水/亲水特性的改性双层膜有望在未来的研究中在膜蒸馏中实现有效的分离。
