College of Materials and Chemical Engineering, Heilongjiang Institute of Technology, Harbin, 150050, PR China; State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, PR China; Dalian SEM Bio-Engineering Technology Co., Ltd., Dalian, 116620, PR China.
School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou, 510275, PR China; Guangdong Provincial Key Laboratory of Environmental Pollution Control and Remediation Technology, Sun Yat-sen University, Guangzhou, 510275, PR China.
J Hazard Mater. 2020 Jul 5;393:122435. doi: 10.1016/j.jhazmat.2020.122435. Epub 2020 Mar 2.
Biochar (BC) has attracted much attention owing to its superior sorption capacity towards ionized organic contaminants. However, the mechanism of ionized organics sorption occurring within BC containing large amounts of minerals is still controversial. In this study, we demonstrate the physicochemical structure of high-salinity microalgal residue derived biochar (HSBC) and elucidate the corresponding sorption mechanisms for four ionized dyes along with determining the crucial role of involved minerals. The results indicate that sodium and calcium minerals mainly exist within HSBCs, and the pyrolysis temperature can dramatically regulate the phases and interfacial property of both carbon matrix and minerals. As a result, the HSBC shows a higher sorption potential, benefiting from abundant functional groups and high content of inorganic minerals. Using theoretical calculations, the activities of electron donor-acceptor interaction between HSBCs and different dyes are clearly illustrated, thereby identifying the critical role of Ca in enhancing the removal of ionized dyes in HSBCs. In addition, Ca-containing minerals facilitate the sorption of ionized dyes in HSBCs by forming ternary complexes through metal-bridging mechanism. These results of mineral-induced dye sorption mechanisms help to better understand the sorption of ionized organics in high-salt containing BC and provide a new disposal strategy for hazardous microalgal residue, as well as provide a breakthrough in making the remediation of ionized organic contaminated microalgal residue derived absorbent feasible.
生物炭（BC）因其对离子化有机污染物的优异吸附能力而备受关注。然而，大量矿物质存在的生物炭中离子化有机物的吸附机制仍存在争议。在这项研究中，我们展示了高盐微藻残渣衍生生物炭（HSBC）的物理化学结构，并阐明了四种离子染料的相应吸附机制，同时确定了所涉及矿物质的关键作用。结果表明，钠和钙矿物质主要存在于 HSBC 中，热解温度可以显著调节碳基质和矿物质的相态和界面性质。因此，HSBC 表现出更高的吸附潜力，这得益于丰富的官能团和高含量的无机矿物质。通过理论计算，清楚地说明了 HSBCs 和不同染料之间电子供体-受体相互作用的活性，从而确定了 Ca 在增强 HSBCs 中离子化染料去除方面的关键作用。此外，含 Ca 的矿物质通过金属桥接机制形成三元配合物，促进 HSBCs 中离子化染料的吸附。这些矿物质诱导染料吸附机制的结果有助于更好地理解高盐含量 BC 中离子化有机物的吸附，并为危险微藻残渣的处理提供了新的策略，同时为离子化有机污染微藻残渣衍生吸收剂的修复提供了突破。
