Extensive research has been focused on the removal of various pollutants from wastewaters. Hexavalent chromium Cr(VI) is of special concern as it is a known carcinogen. In the present study, macroporous polyaniline/poly(vinyl alcohol) aerogel was applied as a promising material form which can act as both adsorbent and reductant for Cr(VI) in aqueous solutions. The removal of Cr(VI) was assessed by monitoring the decrease in optical absorption with UV–visible absorption spectroscopy. The effect of different parameters, such as the initial Cr(VI) concentration, contact time, and the adsorbent dose, on the removal process has been studied. The intraparticle diffusion model was found to characterize the adsorption process well, but Freundlich isotherm best fits the adsorption isotherm data. Investigation of the substrate regeneration revealed that polyaniline-based aerogel can be reused for the removal of Cr(VI) with good efficiency. The maximum adsorption capacity of composite aerogel reached 41.2 mg g⁻¹, which is one of the best results reported in the literature. The conductivity and electroactivity of the material may subsequently be used in the design of intelligent adsorbents when the adsorption/desorption could be controlled by the applied electrical potential.

中文翻译：

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导电大孔聚苯胺/聚乙烯醇气凝胶，用于从水性介质中去除六​​价铬

广泛的研究集中于从废水中去除各种污染物。由于六价铬Cr（VI）是已知的致癌物，因此特别受到关注。在本研究中，大孔聚苯胺/聚乙烯醇气凝胶被用作一种有前途的材料形式，既可以作为水溶液中Cr（VI）的吸附剂也可以作为还原剂。通过用紫外-可见吸收光谱法监测光吸收的降低来评估Cr（VI）的去除。研究了不同参数（例如初始Cr（VI）浓度，接触时间和吸附剂剂量）对去除过程的影响。发现颗粒内扩散模型很好地描述了吸附过程，但Freundlich等温线最适合吸附等温线数据。对基质再生的研究表明，基于聚苯胺的气凝胶可以有效地去除Cr（VI）。复合气凝胶的最大吸附容量达到41.2 mg g^-1，这是文献报道的最佳结果之一。当可以通过施加的电势控制吸附/解吸时，该材料的电导率和电活性可随后用于智能吸附剂的设计中。