Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Radiochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085, India.
Water Res. 2018 Apr 15;133:87-98. doi: 10.1016/j.watres.2018.01.023. Epub 2018 Jan 16.
Recycling of acid from aqueous waste streams is highly important not only from the environmental point of view but also for developing the sustainable technology. One of the effective ways to recover acid from aqueous waste streams is the anion-exchange membrane based diffusion-dialysis. The work presents the synthesis and characterization of anion-exchange pore-filled membranes for the objective of recovery of high concentration of acid by diffusion dialysis. The membranes were prepared by anchoring the guest organic-inorganic anionic gel in the pores of the host poly(propylene) membrane by in situ UV-initiator induced polymerization of the appropriate monomers along with cross-linker. The removal of nitric acid in the presence of different representative monovalent, divalent and trivalent nitrates and the leakage of these ions through anion exchange membrane have been studied by DD technique for optimizing the chemical composition of the membrane. The nitric acid permeation rate of the membrane with the optimized composition has been found to be considerably faster than the commercial Selemion membrane without sacrificing salt leakage. The performance of the optimized pore-filled anion exchange membranes has been found to be independent of the acid concentration, nature of the anion and substrate and has been observed to be solely dependent on the guest inorganic-organic hybrid anionic gel component. The membranes have been found to be stable and reusable for the acid recovery. Removal of nitric acid as high as 90% from the simulated high level nuclear waste with the optimized grafted pore-filled membrane has been achieved with negligible salt transport.
从环保角度和开发可持续技术的角度来看，从水溶液废物流中回收酸非常重要。从水溶液废物流中回收酸的有效方法之一是基于阴离子交换膜的扩散渗析。本工作提出了合成和表征阴离子交换孔填充膜，以通过扩散渗析回收高浓度酸。通过将合适的单体与交联剂一起原位 UV 引发聚合，将客体有机-无机阴离子凝胶锚定在主体聚（丙烯）膜的孔中，制备了膜。通过 DD 技术研究了在不同代表性单价、二价和三价硝酸盐存在下硝酸的去除以及这些离子通过阴离子交换膜的泄漏，以优化膜的化学组成。具有优化组成的膜的硝酸渗透速率明显快于商业 Selemion 膜，而不会牺牲盐泄漏。优化的孔填充阴离子交换膜的性能与酸浓度、阴离子和基质无关，仅取决于客体无机-有机杂化阴离子凝胶组分。发现这些膜稳定且可重复使用，可用于回收酸。使用优化的接枝孔填充膜，从模拟的高放核废料中去除高达 90%的硝酸，盐传输可忽略不计。
