Anionic dyes find widespread applications in an array of industrial processes, which leads to generation of toxic dye wastewater that is of great environmental concern. Adsorption is a widely used method for dye removal because of its effectiveness and simplicity. In particular, cross-linked resins are pivotal due to the advantages of fine-tuning their porosity, surface functionalities, and ease of regeneration under milder conditions. Herein, we wish to provide recent advances on the challenges and opportunities of adsorptive removal of anionic dyes from contaminated water by hyper-crosslinked resins. We present a brief critical comparative analysis of the existing approaches for the removal of anionic dyes, followed by extensive elaboration on the adsorptive removal of anionic dyes by polymeric resins. Discussion on the role of porosity, surface area, and presence of active functionalities in the adsorption efficiency is covered. In addition, critical factors such as optimization of maximum adsorption capacity, adsorption mechanisms that influence dye separation, and regeneration/recyclability of adsorbents are also reviewed. Moreover, we have delineated in detail the influence of pH on the structure and properties of anionic dyes. Furthermore, a detailed discussion on the toxicity and hazardous effects of anionic dyes on human health, aquatic life and the environment, have been reviewed. Finally, a discussion on the research gaps and possible viable solutions on the topic is also covered. We believe that this review will provide a basis to discover efficient and cost-effective adsorbents for the removal of anionic dyes from wastewater.

中文翻译：

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交联树脂去除阴离子染料的批判性综述：近期进展、挑战和未来展望


阴离子染料在一系列工业过程中得到了广泛的应用，这导致产生有毒染料废水，对环境造成了极大的影响。吸附是一种广泛使用的染料去除方法，因为它有效且简单。特别是，交联树脂至关重要，因为它具有微调其孔隙率、表面功能以及在较温和条件下易于再生的优势。在本文中，我们希望提供有关通过超交联树脂吸附去除受污染水中阴离子染料的挑战和机遇的最新进展。我们对现有的去除阴离子染料的方法进行了简短的批判性比较分析，然后对聚合物树脂吸附去除阴离子染料进行了广泛的阐述。讨论了孔隙率、表面积和活性官能团的存在对吸附效率的影响。此外，还综述了关键因素，例如最大吸附容量的优化、影响染料分离的吸附机制以及吸附剂的再生/可回收性。此外，我们还详细描述了 pH 值对阴离子染料结构和性能的影响。此外，还详细讨论了阴离子染料对人类健康、水生生物和环境的毒性和有害影响。最后，还讨论了该主题的研究差距和可能的可行解决方案。我们相信，本综述将为发现用于去除废水中阴离子染料的高效且具有成本效益的吸附剂提供基础。