面向高盐染料废水资源化的复合式双极膜电渗析及其离子迁移机制

With the development in the concept of environmental sustainability, the high-salinity dye wastewater has been regarded as a potential value-added resource. The exploration of novel membrane technology for effective fractionation of dye and salt is critical for the resource extraction from the high-salinity dye wastewater. This research proposes the hybrid bipolar membrane electrodialysis (BMED) technology, which emerges the selectively permeable and porous membrane into the conventional BMED stack, to sufficiently fractionate the dye and salt and simultaneously realize the dye purification, base/acid regeneration, and zero liquid discharge. The study employs the loose nanofiltration membrane as selectively permeable and porous membrane for systematical physico-chemical characterization with the combination of its migration kinetics of different ionic species to reveal the mechanism of its ion migration in the hybrid BMED stack. Furthremore, the fouling behavior of selectively permeable and porous membrane caused by dye molecules and its effect on ion migration will be investigated to demonstrate the fouling mechanism of selectively permeable and porous membrane. The results of this study will not only provide a solid theoretical and technical support for the industrial application of hybrid BEMD technology in high-salinity dye wastewater, but also offer a guideline for its extensive application in other organic wastewaters with high salinity.

随着对环境可持续发展理念的深入理解，高盐染料废水已成为一种可高值化利用的潜在资源。研究开发高效分离染料和盐分的新型膜技术是实现高盐染料废水资源化处理的关键。本项目提出复合式双极膜电渗析技术，于传统双极膜电渗析膜堆中添置选择透过性多孔膜，可高效分离高盐染料废水中的染料与无机盐，并同步实现染料提纯、酸碱制备及废水零排放等多重功效。本项目以疏松纳滤膜做作为选择透过性多孔膜并进行物化特性表征，结合其在复合式双极膜电渗析膜堆中的无机盐和染料迁移动力学，建立选择透过性多孔膜物化性质与其离子迁移动力学之间的内在联系，以阐明其在膜堆中的离子迁移机制；进一步研究染料在选择透过性膜表面的沉积速率与形态及膜污染对离子迁移的影响规律，揭示选择透过性多孔膜的污染机理，为复合式双极膜电渗析技术在高盐染料废水的资源化处理中的工业应用提供理论基础，也为拓展此技术在其他高盐有机废水体系中的应用提供技术思路。

随着对环境可持续发展理念的深入理解，高盐染料废水已成为一种可高值化利用的潜在资源。研究开发高效分离染料和盐分的新型膜技术是实现高盐染料废水资源化处理的关键。本项目提出复合式电渗析技术，采用疏松纳滤膜代替传统电渗析膜中的阴离子交换膜，结合传统电渗析和纳滤的技术优势，通过单一化工单元操作可高效分离高盐染料废水中的染料与无机盐，并同步实现染料提纯、无机盐回收及废水零排放等多重功效。其中，NaCl的脱盐率达到99.0%，而染料的回收率达到99.3%；同时，疏松电纳滤膜表现出优良的抗污染性能。经过5次循环运行后，染料对疏松电纳滤膜表面几乎没有造成任何污染。另外，结合疏松纳滤膜在复合式电渗析膜堆中的无机盐和染料迁移动力学，建立了选择透过性多孔膜物化性质与其离子迁移动力学之间的内在联系，以阐明其在膜堆中的离子迁移机制，为复合式电渗析技术在高盐染料废水的资源化处理中的工业应用提供理论基础，也为拓展此技术在其他高盐有机废水体系中的应用提供了技术思路。