PDF(Pubmed)
Abstract：
The increasing presence of microbial and emerging organic contaminants pose detrimental effects on the environment and ecosystem such as diseases, pandemics and toxicity. Most of these synthetic pollutants are biorecalcitrant and therefore persist in the environment. Conventional water treatment methods are not effective thereby necessitating the development of advanced techniques such as photocatalysis and membrane processes. In this study, visible light-driven photocatalytic membrane was synthesized through the immobilization of nitrogen-doped nanoparticles onto the polyvinylidene fluoride (PVDF) membrane and performance evaluated with E.coli microbial contaminant removal. Characterization was done using Fourier transform infrared spectra, X-ray diffraction (XRD), water contact angle, Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX). The Nitrogen-doping of titanium dioxide red-shifted the light absorption to a visible range of 440 nm from 400 nm. Nitrogen dopant was detected at 1420 cm-1and 1170 cm-1 for nitrogen doped nanoparticles and 1346-1417 cm-1 for nitrogen doped titanium dioxide PVDF membrane. SEM-EDX confirmed presences of nitrogen in nitrogen doped titanium dioxide nanoparticles on membrane surface with nitrogen elemental composition of 0.01 % wt. The water contact angle reduced by 81.39o from 120.14o to 38.75o because of PVA immobilization of nitrogen-doped titanium dioxide and glutaraldehyde crosslinking. Nitrogen doping resulted in visible light active photocatalytic membranes with better hydrophilicity and fouling resistance. 8.42 E.coli log removal and a relative flux of 0.35 was obtained within 75 min. The developed photocatalytic membrane enables the use of sunlight hence a less costly method for decontamination of wastewater.
摘要：
微生物和新兴有机污染物的增加对环境和生态系统造成有害影响，如疾病，大流行和毒性。这些合成污染物中的大多数是生物顽固的，因此会在环境中持续存在。常规的水处理方法是无效的,因此需要开发先进的技术,例如光催化和膜工艺。在这项研究中,通过将氮掺杂的纳米颗粒固定到聚偏氟乙烯（PVDF）膜上，合成了可见光驱动的光催化膜，并通过大肠杆菌微生物污染物去除进行了性能评估。使用傅里叶变换红外光谱进行表征，X射线衍射(XRD)水接触角,扫描电子显微镜-能量色散X射线(SEM-EDX)。二氧化钛的氮掺杂将光吸收从400nm红移到440nm的可见范围。对于氮掺杂的纳米颗粒，在1420cm-1和1170cm-1处检测到氮掺杂剂，对于氮掺杂的二氧化钛PVDF膜，在1346-1417cm-1处检测到氮掺杂剂。SEM-EDX证实了氮元素组成为0.01wt％的膜表面上氮掺杂的二氧化钛纳米颗粒中存在氮。由于PVA固定了氮掺杂的二氧化钛和戊二醛交联，水接触角从120.14o降低了81.39o至38.75o。氮掺杂导致可见光活性光催化膜具有更好的亲水性和抗污性。8.42E.大肠杆菌对数去除和0.35的相对通量在75分钟内获得。开发的光催化膜能够使用阳光，因此是一种成本较低的废水净化方法。
