Biochar from Chinese herb residues as adsorbent for toxic metals removal

3rd International Conference on Energy Materials and Environment Engineering

能源学;生态环境科学

Liu, Guocheng^1 ; Huang, Yu^2 ; Xu, Lina^1

Key Laboratory of Marine Environment and Ecology, Ministry of Education, College of Environmental Science and Engineering, Ocean University of China, Qingdao

266100, China^1

Gansu Institute of Urban Planning and Design, Lanzhou

730000, China^2

关键词: Aqueous phase;    Bio chars;    Chinese herbs;    Initial concentration;    Removal rate;    Slow pyrolysis;    Toxic metal ions;    Toxic metals;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/61/1/012147/pdf
DOI  :  10.1088/1755-1315/61/1/012147

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Two biochars were prepared form Chinese herb residues by slow pyrolysis at 300 °C and 600 °C (CHR300 and CHR600) for removing two toxic metal ions (Pb2+and Cd2+) from aqueous phase. In this study, both Pb2+and Cd2+were effectively immobilized by CHR300 and CHR600 from water. For an initial concentration of Pb2+and Cd2+(C0= 10 mg/L), the removal rate by CHR300 and CHR600 were all greater than 90.0% at a solid:liquid ratio of 50 mg biochar in 10 mL solution. For C0of the two toxic metals was 100 mg/L, the Pb2+removal by CHR600 was significantly stronger than that by CHR300, but there was no significant difference of the removal rate of Cd2+between CHR300 and CHR600. Moreover, the removal rate of Pb2+by CHR300 and CHR600 was both markedly greater than that of Cd2+, indicating that the biochars had stronger adsorption favorite for Pb2+than Cd2+. The SEM-EDX data of the biochars after the toxic metals sorption drew strong evidences on the Pb2+and Cd2+immobilization by CHR300 and CHR600. The existing of phosphorus (P) and sulphur (S) in CHR300 and CHR600 implied that the heavy metals might be removed by forming Pb/Cd-P and Pb/Cd-S precipitates. These results suggested that the biochars from Chinese herb residues would be likely to be good adsorbents for Pb2+and Cd2+removal in water.