Karkoosh Hasan, Vithanage Meththika, Sarmah Ajit K
Department of Civil and Environmental Engineering, The Faculty of Engineering, The University of Auckland, Private Bag 92019, Auckland, 1072, New Zealand.
Ecosphere Resilience Research Centre, Faculty of Applied Sciences, University of Sri Jayewardenepura, Gangodawila, 10250, Sri Lanka.
Environ Pollut. 2023 May 15;325:121435. doi: 10.1016/j.envpol.2023.121435. Epub 2023 Mar 14.
We investigated the feasibility of two novel engineered biochar composites by pyrolyzing cabbage leaves at 350 °C after pre-treating them with anthocyanin, followed by a post-treatment with kaolinite for the removal of two potentially toxic elements (copper and lead) and a pharmaceutical compound, metoprolol. Results showed that the Kaolinite-biochar composite (KB) exhibited the highest adsorption capacity, 188.67 and 48.07 mg/g for Pb and Cu at pH 5, and the anthocyanin-biochar composite (AB) exhibited the highest adsorption capacity: 41.15 mg/g for metoprolol at pH 6, compared to raw biochar respectively. The enhancement of the adsorption of heavy metal and metoprolol by KB and AB was due to an increase in certain oxygen functional groups, as confirmed by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) results. The pseudo-second order kinetic model, along with Langmuir isotherm model, best described the kinetic and the isotherms for Pb, Cu and metoprolol in KB and AB composites, respectively. FTIR, XPS, and zeta potential measurements indicated that the sorption mechanisms involved electrostatic interaction, ion exchange, and complexation for the metals, while electrostatic interaction, H-bonding, π-πinteraction, and hydrophobic bonding were postulated as the contributing mechanisms in the sorption process of metoprolol. Anthocyanin and kaolinite could potentially be considered as alternative sustainable materials for modifying raw biochar and remediating toxic elements and pharmaceuticals in aqueous media.
我们研究了两种新型工程生物炭复合材料的可行性，方法是先将卷心菜叶用花青素预处理，然后在350℃下热解，接着用高岭土进行后处理，以去除两种潜在有毒元素（铜和铅）以及一种药物化合物美托洛尔。结果表明，高岭土 - 生物炭复合材料（KB）表现出最高的吸附容量，在pH为5时对铅和铜的吸附容量分别为188.67和48.07mg/g，而花青素 - 生物炭复合材料（AB）表现出最高的吸附容量：在pH为6时对美托洛尔的吸附容量为41.15mg/g，与原始生物炭相比。KB和AB对重金属和美托洛尔吸附的增强归因于某些氧官能团的增加，这由X射线光电子能谱（XPS）和傅里叶变换红外光谱（FTIR）结果证实。伪二级动力学模型以及朗缪尔等温线模型分别最能描述KB和AB复合材料中铅、铜和美托洛尔的动力学和等温线。FTIR、XPS和zeta电位测量表明，吸附机制涉及金属的静电相互作用、离子交换和络合作用，而静电相互作用、氢键、π - π相互作用和疏水键被假定为美托洛尔吸附过程中的作用机制。花青素和高岭土有可能被视为改性原始生物炭以及修复水介质中有毒元素和药物的替代可持续材料。
