| 污泥水热炭对亚甲基蓝的吸附特性 |
| 摘要点击 2073 全文点击 605 投稿时间：2019-08-23 修订日期：2019-11-23 |
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| 中文关键词 污泥 水热碳化 吸附剂 亚甲基蓝 水热炭 |
| 英文关键词 sludge hydrothermal carbonization adsorbent methylene blue hydrochar |
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| 中文摘要 |
| 为了制备价廉高效的吸附材料，采用污水厂污泥为原料，以水热碳化法（hydrothermal carbonization，HTC）在不同温度（160、190、220和250℃）和不同反应时间（1、4、8和16 h）的条件下，制备出污泥水热炭（hydrochar）并应用于水中亚甲基蓝（methylene blue，MB）的吸附.通过BET、FT-IR和零电荷点等表征手段分析了水热炭的结构和理化性质，并结合批次实验、等温吸附和吸附动力学研究了水热炭对MB的吸附特性.结果表明，在190℃和4 h条件下制备的污泥吸附剂（SS190-4），其比表面积最大（11.916 m2·g-1），对亚甲基蓝（MB）的去除率高达96.44%.当溶液pH趋于碱性时更有利于污泥水热炭对MB的吸附，水热炭投加浓度为0.5 g·L-1时较为经济合理，当溶液中有共存离子时会抑制水热炭对MB的吸附能力.水热炭对MB的吸附更符合Langmuir等温方程，R2在0.966~0.988之间，在50℃下，水热炭对MB的最大模型吸附量为400 mg·g-1.其吸附过程符合准二级动力学模型，是自发的放热反应. |
| 英文摘要 |
| 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 m2·g-1) 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-1. When the concentration of hydrochar is 0.5 g·L-1, 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. |
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