Wang Peng-Fei, Zhi Meng-Meng, Chu Zhao-Sheng, Cui Guan-Nan
National Engineering Laboratory for Lake Pollution Control and Ecological Restoration, State Environment Protection Key Laboratory for Lake Pollution Control, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
School of Environmental and Municipal Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China.
Huan Jing Ke Xue. 2020 Dec 8;41(12):5480-5487. doi: 10.13227/j.hjkx.202005063.
To study the effect of biomass particle size on the rate and ability of phosphorus removal from aqueous solution by MgO-loaded biochar (MBC), MBC was prepared using 0.0-0.5, 1.0-2.0, and 6.0-8.0 mm particles as the feedstock and MgCl as the modification material. The MBC was characterized using FTIR, XRD, and SEM techniques. Kinetic and isotherm experiments of phosphate (PO-P) adsorption from aqueous solution by the MBC were conducted, and the experimental data were fitted with various kinetic and isotherm models. The results showed that the adsorption rate of PO-P by the MBC increased with the increase in biomass particle size. The amount of PO-P adsorbed by the MBC prepared from 0.0-0.5, 1.0-2.0, and 6.0-8.0 mm particles reached 15.4%, 25.8%, and 80.8%, respectively, within 2 h. The biomass particle size did not affect the maximum PO-P adsorption capacity (249.0-254.7 mg·g) of the MBC. MBC prepared from the 6-8 mm particles retained the complete cell wall structure of the , and a large number of micropores and mesopores were generated during pyrolysis, thereby forming a hierarchical, regular, and well-connected pore structure. MBC prepared from the 0.0-0.5 mm and 1.0-2.0 mm particles had inferior pore structures with inferior pore connectivity, which affected the diffusion rate of PO ions inside the MBC and limited the PO-P adsorption rate. Therefore, when using waste harvested from a constructed wetland to produce MBC and remove phosphorus from water, the should be crushed into 6-8 mm particles. Over-crushing deteriorates the pore structure of the produced MBC and reduces the removal rate of phosphorus by the MBC.
为研究生物质粒径对载氧化镁生物炭（MBC）从水溶液中去除磷的速率和能力的影响，以0.0 - 0.5、1.0 - 2.0和6.0 - 8.0毫米的颗粒为原料、MgCl为改性材料制备了MBC。采用傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）和扫描电子显微镜（SEM）技术对MBC进行了表征。进行了MBC对水溶液中磷酸盐（PO-P）吸附的动力学和等温线实验，并将实验数据与各种动力学和等温线模型进行拟合。结果表明，MBC对PO-P的吸附速率随生物质粒径的增大而增加。由0.0 - 0.5、1.0 - 2.0和6.0 - 8.0毫米颗粒制备的MBC在2小时内对PO-P的吸附量分别达到15.4%、25.8%和80.8%。生物质粒径不影响MBC的最大PO-P吸附容量（249.0 - 254.7毫克·克）。由6 - 8毫米颗粒制备的MBC保留了生物质的完整细胞壁结构，热解过程中产生了大量微孔和介孔，从而形成了分级、规则且连通良好的孔隙结构。由0.0 - 0.5毫米和1.0 - 2.0毫米颗粒制备的MBC孔隙结构较差，孔隙连通性欠佳，这影响了PO离子在MBC内部的扩散速率，限制了PO-P的吸附速率。因此，利用人工湿地收获的生物质制备MBC并去除水中磷时，应将生物质粉碎成6 - 8毫米的颗粒。过度粉碎会使所制备MBC的孔隙结构恶化，降低MBC对磷的去除率。
