Wang Chengyu, Xiao Wangze, Li Qinqin, Tian Xiaochun, Xu Jinlong, Ding Kangle
College of Chemistry and Environmental Engineering, Yangtze University, Jingzhou, 434023, Hubei, China.
Sci Rep. 2025 Jul 1;15(1):22176. doi: 10.1038/s41598-025-07240-x.
This study investigates the use of hydrochars derived from sweet potato residue (Ipomoea batatas), Indian mallow (Abutilon theophrasti Medicus), and Nan bamboo (Phyllostachys edulis) for diesel adsorption in oily wastewater treatment. Hydrochars were prepared via hydrothermal carbonization, and their adsorption kinetics and thermodynamics were evaluated. The optimal adsorption conditions for sweet potato residue hydrochar (SPRH) were: 1.8 g·L dosage, 479 mg·L diesel concentration, pH 4-, and 120-min adsorption time, with a capacity of 165.52 mg·g. Kinetic studies revealed that adsorption followed a pseudo-second-order model, and the isotherm fitted the Langmuir model. For Indian mallow hydrochar (IMH), optimal conditions were: 1.4 g·L dosage, 398 mg·L diesel concentration, pH 3.18, and 100 min, achieving 157.41 mg·g capacity. IMH adsorption also followed the pseudo-second-order model, driven by chemical adsorption. Nan bamboo hydrochar (NBH) showed optimal conditions at 1.8 g·L dosage, 502 mg·L diesel concentration, pH 3.92, and 120 min, with a diesel adsorption capacity of 193.75 mg·g. Chemical modification of NBH with KMnO, HO, HPO, and HNO improved adsorption by 12.38-21.25%. After four adsorption-desorption cycles, modified NBH retained 63.24% of its initial capacity, indicating good stability and regeneration potential. These findings suggest that modified NBH offers a cost-effective, efficient solution for oily wastewater treatment.
本研究考察了由甘薯残渣（番薯）、苘麻（苘麻）和楠竹（毛竹）制备的水热炭在含油废水处理中对柴油的吸附性能。通过水热碳化制备水热炭，并对其吸附动力学和热力学进行了评估。甘薯残渣水热炭（SPRH）的最佳吸附条件为：投加量1.8 g·L、柴油浓度479 mg·L、pH值4 - 、吸附时间120 min，吸附量为165.52 mg·g。动力学研究表明，吸附遵循准二级模型，等温线符合朗缪尔模型。对于苘麻水热炭（IMH），最佳条件为：投加量1.4 g·L、柴油浓度398 mg·L、pH值3.18、吸附时间100 min，吸附量达到157.41 mg·g。IMH的吸附也遵循准二级模型，受化学吸附驱动。楠竹水热炭（NBH）的最佳条件为：投加量1.8 g·L、柴油浓度502 mg·L、pH值3.92、吸附时间120 min，柴油吸附量为193.75 mg·g。用KMnO₄、H₂O₂、H₃PO₄和HNO₃对NBH进行化学改性后，吸附量提高了12.38% - 21.25%。经过四个吸附 - 解吸循环后，改性NBH保留了其初始容量的63.24%，表明其具有良好的稳定性和再生潜力。这些研究结果表明，改性NBH为含油废水处理提供了一种经济高效的解决方案。
