In this research, thin-film composite (TFC) membranes were used for separating metronidazole antibiotic from effluents. In order to enhance the metronidazole separation performance, thin-film nanocomposite (TFNC) membranes containing copper sulfide nanoparticles as well as modified thin-film nanocomposite (MFTNC) membranes containing copper sulfide nanoparticles coated with acrylic acid were employed. The spherical morphology of CuS nanoparticles along with the acrylic acid chains coated on their surface was confirmed through TEM, scanning electron microscopy (SEM) and energy dispersive X-Ray spectroscopy (EDS) analysis. The crystalline size of nanoparticles was obtained as 29 nm according to XRD. The effect of nanoparticles on chemical functional groups and membrane elemental analysis was investigated by FTIR and CHNS analysis. The structural comparison of TFC, TFNC, and MTFC membranes indicated that the degree of grafting (DG) of the composite thin-film was 17.2, 27.2, and 46.1%, respectively. The structural modification caused the contact angle of TFC, TFNC, and MTFNC to diminish by 47, 34, and 21°, and their porosity to rise by 37, 67, and 53%, respectively. Improvement of porosity and surface hydrophilicity resulted in flux recovery of 87, 100, and 100% in metronidazole filtration by TFC, TFNC, and MTFNC membranes respectively. AFM analysis reported lower roughness of TFNC and MTFNC compared to TFC roughness, obtained in response to less fouling for TFNC and MTFNC over TFC. The size of pores of TFC, TFNC, and MTFNC membranes was measured as 26.5, 16.8, and 14.5 nm respectively, bringing about metronidazole separations of 86.3%, 87.5%, and 98.3%, respectively.

中文翻译：

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改进薄膜复合膜结构以实现废水中甲硝唑抗生素高级分离的策略

在这项研究中，薄膜复合 (TFC) 膜用于从废水中分离甲硝唑抗生素。为了提高甲硝唑的分离性能，采用了含有硫化铜纳米颗粒的薄膜纳米复合材料 (TFNC) 膜以及含有涂有丙烯酸的硫化铜纳米颗粒的改性薄膜纳米复合材料 (MFTNC) 膜。通过 TEM、扫描电子显微镜 (SEM) 和能量色散 X 射线光谱 (EDS) 分析证实了 CuS 纳米粒子的球形形态以及涂覆在其表面上的丙烯酸链。根据XRD，纳米颗粒的结晶尺寸为29nm。通过FTIR和CHNS分析研究了纳米颗粒对化学官能团和膜元素分析的影响。TFC、TFNC 和 MTFC 膜的结构比较表明，复合薄膜的接枝度 (DG) 分别为 17.2、27.2 和 46.1%。结构改性导致 TFC、TFNC 和 MTFNC 的接触角分别减小 47、34 和 21°，孔隙率分别增加 37、67 和 53%。孔隙率和表面亲水性的改善导致通过 TFC、TFNC 和 MTFNC 膜在甲硝唑过滤中的通量回收率分别为 87%、100% 和 100%。AFM 分析表明，与 TFC 粗糙度相比，TFNC 和 MTFNC 的粗糙度较低，这是由于 TFNC 和 MTFNC 对 TFC 的污染较少而获得的。TFC、TFNC 和 MTFNC 膜的孔径分别测量为 26.5、16.8 和 14.5 nm，使甲硝唑分离率分别为 86.3%、87.5% 和 98.3%。