利用水热碳化法制备的柳枝稷生物炭从水溶液中去除铜和镉。

Removal of copper and cadmium from aqueous solution using switchgrass biochar produced via hydrothermal carbonization process.

机构信息

Department of Civil and Environmental Engineering, Old Dominion University, Norfolk, VA 23529, USA.

出版信息

J Environ Manage. 2012 Oct 30;109:61-9. doi: 10.1016/j.jenvman.2012.04.047. Epub 2012 Jun 9.

DOI:10.1016/j.jenvman.2012.04.047

Abstract

Biochar produced from switchgrass via hydrothermal carbonization (HTC) was used as a sorbent for the removal of copper and cadmium from aqueous solution. The cold activation process using KOH at room temperature was developed to enhance the porous structure and sorption properties of the HTC biochar. The sorption efficiency of HTC biochar and alkali activated HTC biochar (HTCB) for removing copper and cadmium from aqueous solution were compared with commercially available powdered activated carbon (PAC). The present batch adsorption study describes the effects of solution pH, biochar dose, and contact time on copper and cadmium removal efficiency from single metal ion aqueous solutions. The activated HTCB exhibited a higher adsorption potential for copper and cadmium than HTC biochar and PAC. Experiments conducted with an initial metal concentration of 40 mg/L at pH 5.0 and contact time of 24 h resulted in close to 100% copper and cadmium removal by activated HTCB at 2 g/L, far greater than what was observed for HTC biochar (16% and 5.6%) and PAC (4% and 7.7%). The adsorption capacities of activated HTCB for cadmium removal were 34 mg/g (0.313 mmol/g) and copper removal was 31 mg/g (0.503 mmol/g).

摘要

通过水热碳化（HTC）从柳枝稷中生产的生物炭被用作从水溶液中去除铜和镉的吸附剂。开发了使用室温下的 KOH 的冷激活工艺，以增强 HTC 生物炭的多孔结构和吸附性能。比较了 HTC 生物炭和碱性激活的 HTC 生物炭（HTCB）对水溶液中铜和镉的吸附效率，与市售的粉末状活性炭（PAC）进行了比较。本批吸附研究描述了溶液 pH、生物炭剂量和接触时间对从单一金属离子水溶液中去除铜和镉效率的影响。与 HTC 生物炭和 PAC 相比，活化的 HTCB 对铜和镉表现出更高的吸附潜力。在初始金属浓度为 40 mg/L、pH 值为 5.0 和接触时间为 24 h 的实验中，在 2 g/L 时，活化的 HTCB 几乎可以达到 100%的铜和镉去除率，远远高于 HTC 生物炭（16%和 5.6%）和 PAC（4%和 7.7%）。活化 HTCB 对镉的吸附容量为 34 mg/g（0.313 mmol/g），对铜的吸附容量为 31 mg/g（0.503 mmol/g）。