Abstract Green synthesis provides new avenues of nanoparticle synthesis using plants. In the present study, we attempted to synthesise ZnO nanoparticles via precipitation using different ratios of ZnO solution to leaf extract of Cymbopogon citratus (3:1, 5:1, and 9:1). The modified ZnO was characterised using Fourier transform infrared spectroscopy, transmission electron microscopy, and X-ray diffraction. The influences of the modified ZnO-C. citratus (ZnO-CC) nanoparticles on the removal of colour from and decline in the flux of palm oil mill secondary effluent (POMSE) in a membrane photocatalytic reactor (MPR) were studied. The performance of ZnO-CC 3:1 in terms of colour (99.84 %), COD (98.97 %), BOD (96.24 %) and turbidity removal (99.89 %) of the treated POMSE was significant. The improvement of the performance efficiency for POMSE treatment using MPR correlate with the reduction in the size of ZnO-CC 3:1 (6.6–42.9 nm) which promote higher degradation activity and minimize membrane flux decline during the process. Thus, it can be deduced that the coupled MPR system has significant potential for application in the palm oil mill effluent treatment industry as it mitigates membrane fouling and yields treated effluent of good quality.

中文翻译：

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ZnO-Cymbopogon cittratus 膜光催化反应器处理棕榈油厂二次出水的性能

摘要 绿色合成为利用植物合成纳米粒子提供了新途径。在本研究中，我们尝试使用不同比例的 ZnO 溶液与柑橘叶提取物（3:1、5:1 和 9:1）通过沉淀合成 ZnO 纳米颗粒。使用傅里叶变换红外光谱、透射电子显微镜和 X 射线衍射表征改性 ZnO。改性ZnO-C的影响。研究了柑橘 (ZnO-CC) 纳米粒子对膜光催化反应器 (MPR) 中棕榈油厂二次流出物 (POMSE) 的颜色去除和通量下降的影响。ZnO-CC 3:1 在颜色 (99.84 %)、COD (98.97 %)、BOD (96.24 %) 和除浊 (99.89 %) 方面的性能是显着的。使用 MPR 的 POMSE 处理性能效率的提高与 ZnO-CC 3:1 (6.6-42.9 nm) 尺寸的减小相关，这促进了更高的降解活性并最大限度地减少了该过程中膜通量的下降。因此，可以推断耦合 MPR 系统在棕榈油厂废水处理行业具有巨大的应用潜力，因为它可以减轻膜污染并产生高质量的处理过的废水。