Thermodynamics of synthesis and separation performance of Interfacially polymerized “loose” reverse osmosis membrane: Benchmarking for greywater treatment
Thermodynamics of synthesis and separation performance of Interfacially polymerized “loose” reverse osmosis membrane: Benchmarking for greywater treatment
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界面聚合“松散”反渗透膜的合成和分离性能的热力学：灰水处理基准
DOI：
10.1016/j.cej.2020.127929
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发表时间：
2020
影响因子：
15.1
通讯作者：
A. Roy
中科院分区：
文献类型：
--
作者：
Shubham Lanjewar;A. Mukherjee;Priyesh Khandewal;A. Ghosh;Aditi Mullick;S. Moulik;A. Roy
灰水回收是一种有前途的替代方案，以较低的能量代价净化相对清洁的水流。在目前的工作中，灰水处理通过“松散”薄膜复合（TFC）反渗透（RO）膜已被尝试。研究了醋酸纤维素（CA）与聚乙烯吡咯烷酮（PVP）、聚乙二醇（PEG）等添加剂之间的相互作用沿着在N-甲基吡咯烷酮（NMP）溶剂中的相容性。通过稀溶液粘度测定和三元相图研究了CA-PVP、CA-PEG共混物在NMP中的相容性。发现CA-PVP产生比CA-PEG更不稳定的溶液。这反映在它们的膜形态、渗透性和孔隙率上。因此，选择两种膜，一种是最高渗透性的，一种是最低渗透性的，并进行界面聚合以产生“松散”TFC-RO膜。这些经受合成TDS（总溶解固体）水平（500-1000 ppm）和真实生活灰水流。根据自由能的理论热力学分析，计算了实验室规模的分离能。对于合成流，观察到实验分离能量更接近理论最小值。因此，可以得出结论，通过适当的预处理策略，可以以节能的方式处理实际生活中的灰水。
Greywater recycling is a promising alternative to purify a relatively clean stream at a lower energy penalty. In the present work, greywater treatment through “loose” thin-film composite (TFC) reverse osmosis (RO) membranes have been attempted. Polymer interactions between cellulose acetate (CA) and additives like polyvinyl pyrrolidone (PVP) and polyethylene glycol (PEG) have been studied along with their miscibilities in n-methyl pyrrolidone (NMP) solvent. The compatibility was understood through dilute solution viscometry measurements, and ternary phase diagrams, the miscibilities/immiscibilities of the CA-PVP, CA-PEG blends in NMP was explored. It was found that CA-PVP yielded less stable solutions than CA-PEG. This was reflected in their membrane morphologies, permeability, and porosities. Thus, two membranes were chosen, one of the highest permeability and one of the lowest permeability and underwent interfacial polymerization to yield “Loose” TFC – RO membranes. These were subjected to synthetic TDS (Total Dissolved Solids) levels (500–1000 ppm) and real-life greywater streams. The energetics of separation at bench scale against the theoretical thermodynamic analysis of free energy was calculated. For synthetic streams, it was observed that experimental energy of separation was found closer to the theoretical minimum. Thus, it was concluded that with proper pre-treatment strategies, real-life greywater could be treated in an energy-efficient way.