Recyclable high-stability As (III) absorbent from SiO₂ immobilized by ionic liquid [C₄py][DCA]

Selective and efficient removal of As (III) from solution is still a great challenge in water treatment. Herein, a new type of porous absorbent (SI-scd) with large surface area (100.25 m(2).g(-1)) composed of SiO2 and ionic liquid [C(4)py][DCA] was fabricated viasolid surface immobilized method. SI-scd exhibited a maximum adsorption capacity of As (III) (46.003 mg.g(-1) at 298 K), outperforming some commercialized absorbent. Interestingly, SI-scd also showed satisfactory adsorption kinetics behaviors, which can be attributed to a strong coordination bond between N atom of ionic liquid on the surface of SI-scd and As (III). More importantly, the SI-scd displayed good stability and selectivity by using regeneration experiments and batch adsorption experiments. In addition, our porous absorbent also showed good pollution cleaning of As (III) in the actual water environment (lake water and river water). Our findings provide new insights into the absorbent of As (III) with high selectivity and stability on sewage treatment.