A composite of Ni–Fe–Zn layered double hydroxides/biochar for atrazine removal from aqueous solution

Abstract

This study assembled corn stalk-derived biochar (BC) with layered double hydroxide (LDH) through a rapid coprecipitation of biochar and metal (Ni/Fe/Zn) hydroxide precipitates. A BC and LDH composite (BC-LDH) and modified BC-LDH material after heating (BC-LDH-P) were prepared successfully for atrazine adsorptive removal. The physicochemical properties of the synthesized samples were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), and X-ray photoelectron spectroscopy (XPS). Batch experiments were conducted to study the sorption of atrazine onto BC, BC-LDH, and BC-LDH-P from the aqueous solution. The adsorption of atrazine onto BC-LDH and BC-LDH-P were performed following with the pseudo-second-order kinetic model, and the sorption isotherms agreed well with the Freundlich fitting model. The adsorption amounts of the three materials are arranged in descending order is as follows: BC-LDH-P > BC-LDH > BC (143.15 > 123.10 > 95.93 mg g⁻¹, respectively). Due to the high crystallinity of the LDH material and the high binding degree with biochar, Ni/Fe/Zn-LDH biochar composites offer a potential alternative to a carbon-based adsorbent for atrazine removal from aqueous solution.

Funding

the MOA Modern Agricultural Talents Support Project

the Plan for Training Talents with Special Funds for the Development of Local Colleges and Universities by Central Finance

the Second Batch of National“10,000 Person Plan” in 2016

the National Natural Science Foundation of China(31972941)

the Central Committee Guides Local Science and Technology Development Projects(ZY18A05)

Heilongjiang Provincial Key Laboratory of Soil Protection and Remediation