Bifunctional adsorbents obtained by co-precipitation of anionic layered double hydroxides (LDH) on the surface of cationic montmorillonite (MMT) are considered to be more effective than the physical mixtures of the mentioned materials. This is due to high degree of dispersion of the materials and their mutual interactions which improve the rheological properties. Such hybrid composite enables a simultaneous removal of both cationic and anionic pollutants from aqueous solutions. This includes wastewaters from the tanning industry, which often contain chromium(III) from tanning processes and various dyes. In this work, an in-situ synthesis method at room temperature was developed. Four materials were obtained by LDH co-precipitation – Mg/Fe, Mg/Al, Ni/Al and Ni/Fe – in the presence of a smectite-rich sample from Wyoming (SWy). The mass ratio of smectite/LDH was 1:1. For comparison, four analogous physical mixtures of MMT/LDH, raw SWy and LDHs were used in the experiments. The materials were analyzed by XRD, FTIR, SEM/EDS analysis, thermal and textural analysis based on N₂ adsorption/desorption. The effectiveness of removing pollutants was determined in adsorption experiments using Cr(III) cations and anionic dye Acid Blue 129. The conducted experiments showed a high removal capacity of both pollutants by the Mg/Al and Mg/Fe LDH-smectite composites, in single- (up to 100% for AB129 and 97% for Cr(III)), two- (up to 94% for AB129 and 91% for Cr(III)) and multi-component systems (over 62% for AB129 and 99.9% for Cr(III)). The synthesized materials show promising properties in terms of their use as adsorbents for treatment of complex industrial wastewaters.

通过在阳离子蒙脱石 (MMT) 表面上共沉淀阴离子层状双氢氧化物 (LDH) 获得的双功能吸附剂被认为比上述材料的物理混合物更有效。这是由于材料的高度分散性和它们之间的相互作用，从而改善了流变性能。这种混合复合材料能够同时从水溶液中去除阳离子和阴离子污染物。这包括来自制革工业的废水，其中通常含有来自制革工艺和各种染料的铬 (III)。在这项工作中，开发了一种室温下的原位合成方法。在来自怀俄明州 (SWy) 的富含绿土的样品存在下，通过 LDH 共沉淀获得了四种材料——Mg/Fe、Mg/Al、Ni/Al 和 Ni/Fe。绿土/LDH的质量比为1:1。为了比较，实验中使用了 MMT/LDH、原始 SWy 和 LDH 的四种类似物理混合物。通过XRD、FTIR、SEM/EDS分析、基于N的热和质构分析对材料进行分析₂吸附/解吸。在使用 Cr(III) 阳离子和阴离子染料酸性蓝 129 的吸附实验中确定了去除污染物的有效性。所进行的实验表明 Mg/Al 和 Mg/Fe LDH-蒙脱石复合材料对两种污染物的去除能力都很高，在单一的-（AB129 高达 100%，Cr(III) 高达 97%），二元（AB129 高达 94%，Cr(III) 高达 91%）和多组分系统（AB129 超过 62% 和 99.9%对于 Cr(III))。合成材料在用作处理复杂工业废水的吸附剂方面显示出有前景的特性。