Removal of Pb(II) from Aqueous Solution and Adsorption Kinetics of Corn Stalk Biochar
Wenling Yang,
Chaoyang Lu,
Bo Liang,
Chaohui Yin,
Gao Lei,
Baitao Wang,
Xiaokai Zhou,
Jing Zhen,
Shujing Quan,
Yanyan Jing
Affiliations
Wenling Yang
Institute of Biology Co., Ltd., Henan Academy of Sciences, Zhengzhou 450008, China
Chaoyang Lu
Key Laboratory of New Materials and Facilities for Rural Renewable Energy (Ministry of Agriculture and Rural Affaires of China), Henan Agricultural University, Zhengzhou 450002, China
Bo Liang
Henan High Tech Industrial Co., Ltd., Henan Academy of Sciences, Zhengzhou 450008, China
Chaohui Yin
Key Laboratory of New Materials and Facilities for Rural Renewable Energy (Ministry of Agriculture and Rural Affaires of China), Henan Agricultural University, Zhengzhou 450002, China
Gao Lei
Institute of Biology Co., Ltd., Henan Academy of Sciences, Zhengzhou 450008, China
Baitao Wang
Institute of Biology Co., Ltd., Henan Academy of Sciences, Zhengzhou 450008, China
Xiaokai Zhou
Key Laboratory of New Materials and Facilities for Rural Renewable Energy (Ministry of Agriculture and Rural Affaires of China), Henan Agricultural University, Zhengzhou 450002, China
Jing Zhen
Institute of Biology Co., Ltd., Henan Academy of Sciences, Zhengzhou 450008, China
Shujing Quan
Institute of Biology Co., Ltd., Henan Academy of Sciences, Zhengzhou 450008, China
Yanyan Jing
Key Laboratory of New Materials and Facilities for Rural Renewable Energy (Ministry of Agriculture and Rural Affaires of China), Henan Agricultural University, Zhengzhou 450002, China
In this work, the Pb adsorption and removal ability of biochar from simulated Pb(II)-contaminated wastewater, adsorption isotherms, kinetics, and thermodynamics were studied. Adsorption characteristics of biochar on Pb(II) were analyzed by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscope with energy dispersive spectrometer (SEM-EDS). The influence of the pH of the solution, the contact time, and the biochar dose on the removal of Pb(II) were investigated by single-factor design and response surface analysis. With the increase in biochar dose from 2 g/L to 4 g/L in wastewater, the Pb(II) amount adsorbed on biochar reduced from 21.3 mg/g to 17.5 mg/g. A weakly acidic environment was more conducive to the ligand exchange between Pb(II) ions and biochar. Pb(II) adsorption kinetics of biochar showed that the Pseudo-first-order model was more suitable than other employed models to describe the adsorption process. During the isothermal adsorption process, Langmuir and Freundlich’s isotherms fitted the adsorption data very well (R2 > 96%). The Pb (II) adsorption onto biochar was spontaneous in the specified temperature range (298–318 K) and the process was exothermic. Simultaneously, the optimal conditions were a pH of 5, a contact time of 255 min, and a biochar dose of 3 g/L, under which the maximum predicted Pb(II) removal efficiency was 91.52%.
