One-step synthesis of magnetic attapulgite/carbon supported NiFe-LDHs by hydrothermal process of spent bleaching earth for pollutants removal

Magnetic attapulgite/carbon supported NiFe layered double hydroxides (APT/C@NiFe-LDHs) were fabricated based on the spent bleaching earth via a facile and green hydrothermal approach. Multiple characterizations were conducted to illustrate that NiFe-LDHs was successfully anchored on the surface of APT during the preparation process. The magnetic response and adsorption properties of as-prepared composites could be facilely controlled by varying the Ni/Fe molar ratio . As expected, the coating of NiFe-LDHs significantly increased the adsorption ability to pollutants, the resultant composites prepared at the Ni/Fe molar ratio of 1:1 exhibited excellent adsorption capacities for methylene blue , Pb(II), and chlortetracycline hydrochloride of 271.28, 180.90, and 308.21 mg/g, respectively. The high adsorption capacity of the obtained adsorbents could be ascribed to the synergetic effect of the carbon species and NiFe-LDHs. In addition, the adsorbent could be easily separated by magnetic separation technology, and exhibited a stable recyclability after six adsorption-desorption cycles. This work provided a feasible pathway to design and fabricate adsorption materials for wastewater treatment taken into account both high-performance adsorption and cost-effective way.