College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, PR China; Research Institute of Industrial Hazardous Waste Disposal and Resource Utilization, Southwest Petroleum University, Chengdu, Sichuan 610500, PR China.
College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, PR China; Research Institute of Industrial Hazardous Waste Disposal and Resource Utilization, Southwest Petroleum University, Chengdu, Sichuan 610500, PR China.
J Colloid Interface Sci. 2021 Jul;593:390-407. doi: 10.1016/j.jcis.2021.02.133. Epub 2021 Mar 9.
A two-stage method of hydrothermal carbonization and chemical activation technology was applied to prepare a novel, large surface area and rich-pore structure activation-hydrochar from sludge sewage and coconut shell due to its mild, low-cost, and well-developed merits. The pore-making mechanism of activation-hydrochar was discussed by FT-IR, XPS, SEM, TG, TG-MS, XRD, and BET characterization. These results illustrated that the first stage of hydrothermal carbonization achieved the rich-pore structure hydrochar via dehydration, decarboxylation, deamination, and rearrangement reactions. The subsequent KOH activation was conducive to the pore-forming process. Specifically, the pore structure of activation-hydrochar was ameliorated and abundant active adsorption sites were obtained by the modification. The adsorption properties of activation-hydrochar on Methylene Blue (MB) and Congo Red (CR) were systematically investigated, and the max adsorption capacities of those were obtained with 623.37 mg/g and 228.25 mg/g, respectively. The pseudo-second-order kinetics and Langmuir models were both fit to elucidate the adsorption process for both dyes. Thermodynamics revealed adsorption performance accompanied by the spontaneous and endothermic processes. In general, the research clearly indicated the synthesis route for activation-hydrochar, and its further adsorption performance, capacity, and mechanism on MB and CR. This research demonstrated that activation-hydrochar with the abundant surface area and rich-pore structure made it a candidate for the production of effective adsorption material. It is prospective to achieve the utilization of wastes and its further application in wastewater treatment.
两段式水热碳化和化学活化技术被应用于从污泥污水和椰子壳中制备新型的、具有大表面积和丰富孔结构的活化-水炭，因为它具有温和、低成本和发达的优点。通过傅里叶变换红外光谱（FT-IR）、X 射线光电子能谱（XPS）、扫描电子显微镜（SEM）、热重分析（TG）、热重-质谱联用分析（TG-MS）、X 射线衍射（XRD）和比表面积和孔隙度分析（BET）等手段对活化-水炭的造孔机制进行了讨论。这些结果表明，水热碳化的第一阶段通过脱水、脱羧、脱氨和重排反应实现了丰富的孔结构水炭。随后的 KOH 活化有利于成孔过程。具体来说，通过修饰，活化-水炭的孔结构得到了改善，并获得了丰富的活性吸附位。系统研究了活化-水炭对亚甲基蓝（MB）和刚果红（CR）的吸附性能，得到了其最大吸附容量分别为 623.37 mg/g 和 228.25 mg/g。准二级动力学和朗格缪尔模型都拟合了解释两种染料吸附过程。热力学表明，吸附性能伴随着自发和吸热过程。总的来说，该研究清楚地表明了活化-水炭的合成途径，以及其对 MB 和 CR 的进一步吸附性能、容量和机制。该研究表明，具有丰富表面积和丰富孔结构的活化-水炭使其成为生产有效吸附材料的候选材料。有望实现废物的利用及其在废水处理中的进一步应用。
