School of Resources and Environmental Engineering, Wuhan University of Science and Technology, Wuhan, China.
Global Centre for Environmental Remediation, College of Engineering, Science and Environment, The University of Newcastle, Callaghan, NSW, 2308, Australia.
Environ Sci Pollut Res Int. 2023 Jan;30(2):4754-4768. doi: 10.1007/s11356-022-22357-6. Epub 2022 Aug 16.
Adsorption has been considered as a promising remediation technology to separate organic and inorganic agrochemicals from contaminated soil and water. Low-cost adsorbents, including waste derived materials, clay composites, biochar, and biochar modified materials, have attracted enormous attention for the removal of organic contaminants, including pesticides. In this study, iron-modified base-activated biochar (FeBBC) was prepared by pyrolysis (at 400 °C for 1 h) of iron-doped base (KOH) activated sugarcane bagasse for the removal of a widely used insecticide, namely imidacloprid (IMI) from water. The maximum adsorption capacity of the adsorbent (FeBBC) was calculated as 10.33 (± 1.57) mg/g from Langmuir isotherm model. The adsorbents could remove up to ~ 92% of IMI from aqueous solution at 23.8 mg/L IMI. Experimental data fitted well with the Freundlich model and pseudo-second-order model, demonstrating physisorption, as well as chemosorption, contributed to the sorption process. Even at highly acidic/basic solution pH, the FeBBC could remove substantial amount of IMI demonstrating hydrophobic interaction and pore diffusion play vital role for removal of IMI. The slight improving of IMI sorption with increasing solution pH indicated the sorption was also facilitated through ionic interaction alongside physical sorption. However, physical sorption including hydrophobic interaction and pore-filling interaction plays a vital role in the sorption of IMI.
吸附被认为是一种很有前途的修复技术，可以从污染的土壤和水中分离有机和无机农用化学品。包括废衍生材料、粘土复合材料、生物炭和生物炭改性材料在内的低成本吸附剂，因其对有机污染物（包括农药）的去除能力而受到极大关注。在本研究中，通过热解（400°C 1 h）掺杂铁的碱（KOH）激活的甘蔗渣，制备了铁改性碱激活生物炭（FeBBC），用于去除一种广泛使用的杀虫剂，即吡虫啉（IMI）从水中。从 Langmuir 等温线模型计算出吸附剂（FeBBC）的最大吸附容量为 10.33（±1.57）mg/g。在 23.8mg/L IMI 下，吸附剂可以去除高达~92%的 IMI。实验数据很好地符合 Freundlich 模型和拟二级模型，表明物理吸附和化学吸附都有助于吸附过程。即使在高度酸性/碱性溶液 pH 值下，FeBBC 也能去除大量的 IMI，表明疏水相互作用和孔扩散对 IMI 的去除起着至关重要的作用。随着溶液 pH 值的增加，IMI 的吸附略有增加，这表明离子相互作用也促进了物理吸附。然而，物理吸附包括疏水相互作用和孔填充相互作用，在 IMI 的吸附中起着重要作用。
