Chen Li-Yuan, Li Da-Peng, Zhu Wen-Juan, Xu Chu-Tian, Ding Yu-Qin, Huang Yong
School of Environmental Science and Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
Huan Jing Ke Xue. 2020 Apr 8;41(4):1761-1769. doi: 10.13227/j.hjkx.201908198.
A low-cost and efficient adsorbent, based on sewage sludge, was prepared by hydrothermal carbonization. The sludge-hydrochar was prepared at different temperatures (160, 190, 220, and 250℃) and different reaction times (1, 4, 8, and 16 h). It was applied to the adsorption of methylene blue (MB) in water. This study analyzed the structure and physicochemical properties of hydrochar by BET, FT-IR, and zero charge points. In addition, we investigated the optimum hydrothermal conditions for the preparation of adsorbents and adsorption properties for MB by experiments. Studies have shown that 190℃ and 4 h were the best hydrothermal conditions for the preparation of adsorbent (SS190-4). SS190-4 has the largest specific surface area (11.916 m·g) and the best removal rate (96.44%) for methylene blue (MB). The adsorption of MB is more favorable when the solution is alkaline. The adsorption conforms to the Langmuir isotherm equation, and the maximum model adsorption capacity for MB is 400 mg·g. When the concentration of hydrochar is 0.5 g·L, it is more economical and reasonable. When there are coexisting ions in the solution, the adsorption capacity of hydrochar to MB is inhibited. The adsorption process of MB by hydrochar conforms to the quasi-secondary kinetic model, which is a spontaneous exothermic reaction.
通过水热碳化制备了一种基于污水污泥的低成本高效吸附剂。在不同温度（160、190、220和250℃）和不同反应时间（1、4、8和16小时）下制备污泥水热炭，并将其应用于水中亚甲基蓝（MB）的吸附。本研究通过BET、FT-IR和零电荷点分析了水热炭的结构和物理化学性质。此外，通过实验研究了制备吸附剂的最佳水热条件以及对亚甲基蓝的吸附性能。研究表明，190℃和4小时是制备吸附剂（SS190-4）的最佳水热条件。SS190-4具有最大的比表面积（11.916 m·g），对亚甲基蓝（MB）的去除率最高（96.44%）。溶液呈碱性时，亚甲基蓝的吸附更有利。吸附符合Langmuir等温方程，亚甲基蓝的最大模型吸附容量为400 mg·g。当水热炭浓度为0.5 g·L时，更经济合理。溶液中存在共存离子时，水热炭对亚甲基蓝的吸附容量受到抑制。水热炭对亚甲基蓝的吸附过程符合准二级动力学模型，是一个自发的放热反应。
