State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, PR China.
State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, PR China; School of Earth Sciences and Resources, China University of Geosciences, Beijing 100083, PR China.
Environ Pollut. 2022 Oct 1;310:119881. doi: 10.1016/j.envpol.2022.119881. Epub 2022 Aug 8.
The synthesis of clay-biochar composite has been recognized as an effective way to enhance the removal of pollutants. The interaction between clay mineral and biomass during thermal pyrolysis and the sorption capacity for ionic/nonionic organic containments have not been elaborated. In this study, two types of biochar were obtained from pyrolytic carbonization of the cellulosic-rich corn straw (C) and lignin-rich pine wood (P) at 500 or 700 °C. Typical clay minerals kaolinite and montmorillonite were selected to prepare clay-biochar composite. The results showed that the addition of clay mineral could strengthen dehydration reaction of corn straw biomass and reinforce its carbon structure. Montmorillonite-biochar composite owned more CC functional groups and porous structure than kaolinite-biochar composite. The addition of clay minerals could promote electrostatic attraction of ionic formed norfloxacin (NOR) on clay-pine wood biochar. However, the sorption capacity of nonionic diethyl phthalate (DEP) adsorption on clay-corn straw biochar decreased, owing to that clay increased the compactness of the biochar carbon structure, thus inhabited hydrophobic partition of nonionic organic compounds on disordered carbon fraction. The results from this study provide insights into the suitable contaminated site remediation by clay-biochar composite.
粘土-生物炭复合材料的合成已被认为是一种有效去除污染物的方法。然而，粘土矿物与生物质在热解过程中的相互作用及其对离子/非离子有机污染物的吸附能力尚未得到详细阐述。在本研究中，以富含纤维素的玉米秸秆（C）和富含木质素的松木（P）为原料，在 500 或 700°C 下热解碳化得到了两种生物炭。选择典型的粘土矿物高岭土和蒙脱石来制备粘土-生物炭复合材料。结果表明，粘土矿物的添加可以加强玉米秸秆生物质的脱水反应，增强其碳结构。与高岭土-生物炭复合材料相比，蒙脱土-生物炭复合材料具有更多的 CC 官能团和多孔结构。粘土矿物的添加可以促进离子态诺氟沙星（NOR）在粘土-松木生物炭上的静电吸引。然而，非离子态邻苯二甲酸二乙酯（DEP）在粘土-玉米秸秆生物炭上的吸附容量却有所下降，这是因为粘土增加了生物炭碳结构的致密性，从而阻碍了非离子有机化合物在无序碳分上的疏水分配。本研究的结果为粘土-生物炭复合材料在合适的污染场地修复中的应用提供了新的思路。
