Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Department of Chemical and Biomolecular Engineering, National University of Singapore, Singapore, 117585, Singapore.
Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.
Environ Res. 2021 Jan;192:110258. doi: 10.1016/j.envres.2020.110258. Epub 2020 Oct 2.
Utilization of sludge pyrochar (SP) is the terminal step to loop the entire harmless disposal process of sewage sludge with pyrolysis. A new, easily recyclable, and safe adsorbent with well-immobilized heavy metals (HMs) was prepared from SP for ciprofloxacin (CIP) adsorption. The operational conditions for the adsorbent preparation were systematically optimized based on recycling rate and adsorption performance. Additionally, the adsorption conditions, adsorption kinetics, isotherms, and regeneration of adsorbents were further investigated in the present study. The results showed that easily recyclable and safe adsorbents were successfully prepared at 1100 °C under N atmospheric conditions (SPA-N-1100) with a maximum CIP adsorption capacity of 10.42 mg/g. SPA-N-1100 exhibited good CIP adsorption performance at an adsorption temperature of 45 °C and pH between 8.0 and 9.0. The adsorbents were regenerated by thermal desorption at 450 °C with a thorough decomposition of CIP. The adsorption mechanism was mainly dominated by its special porous microspheres-accumulation structure and surface species (e.g., FeP and graphite). Moreover, HMs in the adsorbents were well immobilized in SPA-N-1100 by the generation of new metal mineral phases and encapsulation of melting minerals, which had an ultralow potential for ecological risk during application.
利用污泥热解炭（SP）是将污泥热解整个无害化处理过程循环利用的最后一步。本研究从 SP 中制备了一种新型、易于回收且安全的吸附剂，该吸附剂可固定重金属（HM）。根据回收利用率和吸附性能，系统优化了吸附剂制备的操作条件。此外，还进一步研究了吸附剂的吸附条件、吸附动力学、吸附等温线和再生。结果表明，在 N 气氛下于 1100°C （SPA-N-1100）可成功制备出易于回收且安全的吸附剂，其最大环丙沙星（CIP）吸附容量为 10.42mg/g。SPA-N-1100 在 45°C 的吸附温度和 8.0-9.0 的 pH 值下表现出良好的 CIP 吸附性能。吸附剂在 450°C 下通过热解吸再生，可彻底分解 CIP。吸附机制主要由其特殊的多孔微球-堆积结构和表面物质（如 FeP 和石墨）决定。此外，在 SPA-N-1100 中，HM 被新生成的金属矿物相和熔融矿物的包裹而很好地固定，在应用过程中其生态风险极低。
