Rice husk valorization into sustainable Ni@TiO2/biochar nanocomposite for highly selective Pb (II) ions removal from an aqueous media

Herein, we successfully prepared sustainable nanocomposites from agriculture waste (rice husk)-derived biochar precursor, and followed by nickel-doped, base-treated titanium dioxide nanomaterials loading for efficient lead (Pb2+) removal from aqueous media. By varying the loading contents of active materials, the optimized sample (Ni0.01@Na-TiO2/BC) possessed an efficient Pb2+ adsorption capability of 122.3 mg g(-1) under the under optimum adsorption parameters, which is attributable to its specific surface area (138.09 m(2) g(1)) and excess functional sites. Kinetic and Isothermal examination illustrated that Pb2+ adsorption phenomena was well followed through pseudo 2nd order and Langmuir models. In addition, superior Pb2+ ions adsorption selectivity was recorded by optimized sample in a multi-metallic system over other existing ion (such as Cd2+, Mg2+, Ca2+, Cu2+, and Zn2+). Desorption experiments has been performed by using desorbing agent that demonstrates the good regeneration ability of sample. Hence, these findings provide new insight for the biowaste management by converting them into innovative adsorbents for commercial scale environmental remediation.

Automated summary

In this study, sustainable nanocomposites were successfully prepared from agriculture waste (rice husk)-derived biochar precursor, and loaded with nickel-doped, base-treated titanium dioxide nanomaterials for efficient lead (Pb2+) removal from aqueous media. The optimized sample (Ni0.01@Na-TiO2/BC) exhibited a high Pb2+ adsorption capability of 122.3 mg g(-1) under the optimum adsorption conditions, attributed to its specific surface area and excess functional sites. The kinetic and isothermal examinations showed that the adsorption of Pb2+ followed pseudo 2nd order and Langmuir models. Furthermore, the optimized sample demonstrated superior adsorption selectivity for Pb2+ ions in a multi-metallic system compared to other ions.