Dan Ren,Shu-Ping Ren,Yakai Lin,Jianhong Xu,Xiao-Lin Wang
Many industries produce large amounts of glycerol-based wastewater, which always contains hazardous organic chlorides. Compared with complicated biological treatments or physical adsorption, membrane separation decreases the cost and saves energy. Strong swelling of traditional thin-film composite (TFC) membranes influence the performance in the separation of organic molecules. Here we prepared TFC membranes with an acrylamide-grafted PAN support layer to copolymerize with m-phenylenediamine (MPD) and trimesoyl chloride (TMC). The link of separative layer and support layer was created like a zipper stitching to enhance the stability and resistance for the removal of organic molecules. An aquatic grass-like layer of acrylamide enlarges the surface area and hydrophilicity with superior separation performances (15.8 LMH bar −1 flux, 72.0% rejection of dichloropropanol (DCP) and 64.6% rejection of glycerol (Gl)). The trade-off upper bound was improved to a high level. We also established the simulations of evaporation using Aspen Plus and mathematical models of reverse osmosis to calculate the energy consumption corresponding to the recycle of glycerol-based wastewater. The experimental and theoretical results illustrate the advantages of acrylamide-grafted TFC membranes in the ap-plications to concentrate organic solutes and treat wastewater.
Fang-Fang Chen,Ting Su,Xue-Ting Zhao,Jie-Feng Pan,Li-Fen Liu
Polyamide thin-film composite reverse osmosis (RO) membranes usually suffer from fouling problem, which greatly limits the wide application of RO technology. In this study, a novel rigid-flexible interpenetrating polyamide RO membrane was fabricated via two step modifications to alleviate the membrane fouling during the RO process. The first step modification was carried out by incorporation a new aliphatic diamine of 1,3-diamino-2-propanol (DAPL) into the aromatic m-phenylenediamine (MPD) aqueous solution to react with trimesoyl chloride (TMC) to form a rigid-flexible interpenetration polyamide (PA) separation layer for enhancing its permeability. Then, the second modification was performed by grafting PVA on the top surface of the DAPL-based PA layer to tailor more hydrophilic, smoother and less negatively charged surface and endowed the modified membrane favorable antifouling property. Under the optimized condition, the permeability flux of the modified RO membrane reached 58.6 L/m 2 h with an about 58.8% increase than the pristine RO membrane (about 36.9 L/m 2 h), and the salt rejection was also maintained about 99.6% without any loss. At the same time, the modified RO membrane presented a favorable resistance to the dye foulants of methylene blue (MB) and crystal violet (CV) with flux recovery rate of 76.8% and 84.2% respectively. This study provides a facile and effective way to fabricate a novel antifouling reverse osmosis composite membrane with favorable comprehensive separation performance.
危险品化学品经营许可证（带存储）