School of Resources and Civil Engineering, Northeastern University, Shenyang, 110819, China.
Environ Sci Pollut Res Int. 2022 Jan;29(3):3853-3863. doi: 10.1007/s11356-021-15969-x. Epub 2021 Aug 16.
Biochar (BC) obtained by the co-pyrolysis of municipal sewage sludge (MSS) and sunflower seed shells (SSS) was utilized to support nanoscale zero-valent iron particles (nZVI) for the synthesis of a composite material (nZVI-BC) for Cr(VI) removal from aqueous systems. A series of characterization methods confirmed successful immobilization of nZVI on the surface of biochar with no aggregation. Batch experiments showed that the initial pH, initial Cr(VI) concentration, and nZVI-BC dose all significantly affected the Cr(VI) removal using nZVI-BC. The kinetics for Cr(VI) removal via nZVI-BC could be better explained by the pseudo-second-order (PSO) adsorption model. Adsorption isotherms analysis demonstrated the superior Cr(VI) removal capability of nZVI-BC in comparison to bare nZVI and BC. nZVI-BC can be reused after the regeneration process by applying 0.1 M HSO and 0.1 M NaBH solutions. The reaction mechanism for Cr(VI) removal might involve its chemical reduction on the nZVI-BC surface. Overall, environmentally friendly nZVI-BC was highly efficient in Cr(VI) removal from aqueous systems.
采用共热解市政污泥（MSS）和葵花籽壳（SSS）制备的生物炭（BC）来负载纳米零价铁颗粒（nZVI），合成用于从水溶液中去除 Cr(VI) 的复合材料（nZVI-BC）。一系列的表征方法证实了 nZVI 成功地固定在生物炭表面上，没有发生聚集。批实验表明，初始 pH 值、初始 Cr(VI)浓度和 nZVI-BC 剂量都显著影响了使用 nZVI-BC 去除 Cr(VI)的效果。通过 nZVI-BC 去除 Cr(VI)的动力学可以更好地用伪二级（PSO）吸附模型来解释。吸附等温线分析表明，与裸 nZVI 和 BC 相比，nZVI-BC 具有更好的 Cr(VI)去除能力。经过 0.1 M HSO 和 0.1 M NaBH 溶液的再生过程后，nZVI-BC 可以重复使用。Cr(VI)去除的反应机制可能涉及到 nZVI-BC 表面的化学还原。总体而言，环境友好型 nZVI-BC 对水溶液中的 Cr(VI)去除具有很高的效率。
