Natural-clay-reinforced hydrogel adsorbent: Rapid adsorption of heavy-metal ions and dyes from textile wastewater

In this study, two natural clay minerals were combined with hydrogels to study the influence of natural adsorbents on the adsorption performance of hydrogels. Here, we separately doped bentonite and vermiculite and discussed their mechanical properties and adsorption properties. It was found that the compressive performance of the hydrogel added with clay increased by 21.6% and the swelling performance decreased or increased to varying degrees. Regarding the adsorption performance of hydrogels, it can be seen from the adsorption Langmuir isotherm model that the adsorption capacity of clay–hydrogels is improved to varying degrees (6.6%–15.8%) compared with non-clay–hydrogels, and clay–hydrogels have different degrees of improvement (6.6%–15.8%). The hydrogel has a removal efficiency of more than 95% for low concentrations of heavy-metal ions and dyes. In addition, the clay–hydrogel has low cost and is easy to prepare, and can be recycled many times. Therefore, the material is of great significance for the treatment of pollutants. Practitioner Points The effect of natural clay on the adsorption performance of hydrogels was studied. Clay can enhance the compression and adsorption properties of hydrogels. The adsorption mechanism and adsorption capacity of clay hydrogels were evaluated.