Lv Xifeng, Zhou Xuejian, Yang Ruiqi, Cai Di, Ren Wenqiang
Key Laboratory of Modern Agricultural Engineering, College of Chemistry and Chemical Engineering, Tarim University, Alar 843300, China.
National Energy R&D Center for Biorefinery, Beijing University of Chemical Technology, Beijing 100029, China.
Materials (Basel). 2025 Jul 22;18(15):3434. doi: 10.3390/ma18153434.
Developing energy-efficient and environmentally benign synthesis protocols is crucial to agricultural waste-based adsorbent preparation. This study prepared novel walnut shell-derived adsorbents by enzymatic modification using a green process, and the as-prepared material was used for methylene blue (MB) removal from wastewater. The results showed that under the optimized conditions (100 mg L methylene blue (MB) solution, pH 7, 30 °C, 120 min adsorption time, and 0.14 g adsorbent dosage), WS-1 exhibited an MB removal efficiency of 93.67%, which was only slightly lower than that of WS-2 that was prepared by further carbonization of WS-1 using the low-temperature hydrothermal method (99.01%). Kinetic analysis confirmed WS-1 exhibited pseudo-second-order adsorption kinetics, which were generally similar to those of WS-2. However, the results obtained by the isotherm model followed by the Langmuir model of WS-1 indicated monolayer adsorption involving combined weak chemisorption and physisorption, which was different from the WS-2 (followed the Freundlich model that inferred multilayer chemisorption). In conclusion, this study successfully converted walnut shells, a type of agricultural waste, into functional adsorbents by a novel, simple, and greener enzymatic modification method, thereby achieving dual benefits of waste valorization and wastewater treatment.
开发节能且环境友好的合成方案对于基于农业废弃物的吸附剂制备至关重要。本研究采用绿色工艺通过酶改性制备了新型核桃壳衍生吸附剂，并将所制备的材料用于去除废水中的亚甲基蓝（MB）。结果表明，在优化条件下（100 mg/L亚甲基蓝（MB）溶液、pH 7、30℃、吸附时间120分钟和吸附剂用量0.14 g），WS-1的MB去除效率为93.67%，仅略低于通过低温水热法对WS-1进一步碳化制备的WS-2（99.01%）。动力学分析证实WS-1表现出拟二级吸附动力学，这与WS-2的情况总体相似。然而，等温线模型对WS-1的结果遵循朗缪尔模型，表明其为涉及弱化学吸附和物理吸附相结合的单层吸附，这与WS-2不同（WS-2遵循推断多层化学吸附的弗伦德里希模型）。总之，本研究通过一种新颖、简单且更绿色的酶改性方法成功地将核桃壳这种农业废弃物转化为功能性吸附剂，从而实现了废物增值和废水处理的双重效益。
