Adsorption Characteristics and Mechanism of Cadmium in Water by Alkali and Magnetic Composite Modified Wheat Straw Biochar

被引：12
作者：
Cui Z.-W. [1 ,2 ]
Ren Y.-F. [1 ,2 ,3 ]
Wang W. [1 ,2 ]
Zhang L.-M. [1 ,2 ]
Zhang L.-Y. [1 ,2 ]
Wang X.-Y. [1 ,2 ]
He J.-Y. [1 ,2 ,3 ]
机构：
[1] School of Environmental and Safety Engineering, Changzhou University, Changzhou
[2] Jiangsu Petrochemical Safety and Environmental Engineering Research Center, Changzhou
[3] College of Agriculture, Guizhou University, Guiyang
来源：
Huanjing Kexue/Environmental Science | 2020年 / 41卷 / 07期
关键词：
Adsorption properties; Biochar (BC); Cadmium (Cd); Modification; Recycling;
D O I：
10.13227/j.hjkx.201912025
中图分类号：
学科分类号：
摘要：
Wheat straw biochar (BC) was modified by KOH and magnetics to generate composited modified biochar (FKC). Based on characterization by scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FT-IR), X-ray diffraction (XRD), and magnetic (VSM) techniques, the adsorption characteristics and mechanisms of Cd2+ in water and the effects of temperature, pH value, and dosage on the adsorption characteristics of FKC were studied. The results showed that the modified biochar was loose and porous. The specific surface area of FKC increased by 19.11 times, the number of aromatic and oxygen-containing functional groups such as O-H, C〖FY=,1〗O, and C〖FY=,1〗C increased, and a new functional group Fe-O formed compared to the BC. FKC is magnetic, and its magnetization is 8.43 emu•g-1, which can be recycled and reused. The adsorption of Cd2+ by FKC fitted well with the pseudo-second-order kinetic model and the Langmuir model, indicating that chemical adsorption is the main adsorption mechanism. The theoretical maximum equilibrium adsorption capacity of FKC is 23.44 mg•g-1, which is 1.47 times that of BC. The thermodynamic parameters suggested the adsorption of Cd2+ by FKC was a spontaneous and endothermic process. The adsorption capacity increased with an increase of pH in the region 2-8, and a biochar dosage of 10 g•L-1 was used. After three cycles of adsorption-desorption-adsorption, the adsorption capacity of Cd2+ by FKC still reached 17.71 mg•g-1, indicating that FKC has good reusability. These results can provide a theoretical basis for the application of KOH and magnet-modified biochar from wheat straw to remove heavy metals from contaminated wastewater. © 2020, Science Press. All right reserved.
引用
收藏
页码：3315 / 3325
页数：10
相关论文
共 39 条
[21]  
Ping W, Wu Y, Yang C X, Et al., Properties and mechanism of Cd(Ⅱ) adsorption from waste water by modified banana peel, Transactions of the Chinese Society of Agricultural Engineering, 35, 8, pp. 269-279, (2019)
[22]  
Singh B, Singh B P, Cowie A L., Characterisation and evaluation of biochars for their application as a soil amendment, Australian Journal of Soil Research, 48, 7, pp. 516-525, (2010)
[23]  
Zhang S Q, Yang X, Liu L, Et al., Adsorption behavior of selective recognition functionalized biochar to Cd(Ⅱ) in wastewater, Materials, 11, 2, (2018)
[24]  
Wu Q, Chen J, Clark M, Et al., Adsorption of copper to different biogenic oyster shell structures, Applied Surface Science, 311, pp. 264-272, (2014)
[25]  
Nassar N N., Rapid removal and recovery of Pb(Ⅱ) from wastewater by magnetic nanoadsorbents, Journal of Hazardous Materials, 184, 1-3, pp. 538-546, (2010)
[26]  
Awwad A M, Salem N M., Kinetics and thermodynamics of Cd(Ⅱ) biosorption onto loquat (Eriobotrya japonica) leaves, Journal of Saudi Chemical Society, 18, 5, pp. 486-493, (2014)
[27]  
Bakshi S, Banik C, Rathke S J, Et al., Arsenic sorption on zero-valent iron-biochar complexes, Water Research, 137, pp. 153-163, (2018)
[28]  
Noraini M N, Abdullah E C, Othman R, Et al., Single-route synthesis of magnetic biochar from sugarcane bagasse by microwave-assisted pyrolysis, Materials Letters, 184, pp. 315-319, (2016)
[29]  
Li N, Yang S G, Chen J, Et al., Electro-adsorption of tetracycline from aqueous solution by carbonized pomelo peel and composite with aniline, Applied Surface Science, 386, pp. 460-466, (2016)
[30]  
Keiluweit M, Nico P S, Johnson M G, Et al., Dynamic molecular structure of plant biomass-derived black carbon (biochar), Environmental Science & Technology, 44, 4, pp. 1247-1253, (2010)
1234