吸附
生物炭
化学
稻草
吸热过程
朗缪尔吸附模型
扫描电子显微镜
傅里叶变换红外光谱
解吸
核化学
化学工程
材料科学
热解
无机化学
有机化学
复合材料
工程类
作者
Cui Zhi-wen,Yanfang Ren,Wei Wang,Liming Zhang,Luyun Zhang,Xi-Yue Wang,Junyu He
出处
期刊:PubMed
日期:2020-07-08
卷期号:41 (7): 3315-3325
被引量:9
标识
DOI:10.13227/j.hjkx.201912025
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=O, and C=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.
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