浙江农业学报 ›› 2026, Vol. 38 ›› Issue (5): 944-954.DOI: 10.3969/j.issn.1004-1524.20250062

• 环境科学 • 上一篇    下一篇

基于碳酸氢钠活化的氮掺杂水稻秸秆生物炭的制备及其对镉的吸附

程凯1,2(), 李飞跃1, 何莉莉2,3, 杨承虎2, 汪玉瑛2,3, 吕豪豪2,3, 杨生茂2,3, 刘玉学1,2,3,*()   

  1. 1 安徽科技学院 资源与环境学院, 安徽 凤阳 233100
    2 浙江省农业科学院 环境资源与土壤肥料研究所, 农产品质量安全全国重点实验室, 浙江 杭州 310021
    3 浙江省生物炭工程技术研究中心, 浙江 杭州 310021
  • 收稿日期:2025-01-18 出版日期:2026-05-25 发布日期:2026-06-02
  • 作者简介:程凯,研究方向为生物炭与重金属污染修复。E-mail:18155089603@163.com
  • 通讯作者: *刘玉学,E-mail:liuyuxue505@163.com
  • 基金资助:
    国家重点研发计划子课题(2023YFD1902903)

Preparation of nitrogen-doped rice straw biochar activated by sodium bicarbonate and its adsorption of cadmium

CHENG Kai1,2(), LI Feiyue1, HE Lili2,3, YANG Chenghu2, WANG Yuying2,3, LYU Haohao2,3, YANG Shengmao2,3, LIU Yuxue1,2,3,*()   

  1. 1 College of Resource and Environment, Anhui Science and Technology University, Fengyang 233100, Anhui, China
    2 State Key Laboratory for Quality and Safety of Agro-Products, Institute of Soil, Fertilizer and Environmental Resources, Zhejiang Academy of Agricultural Sciences, Hangzhou 310021, China
    3 Engineering Research Center of Biochar of Zhejiang Province, Hangzhou 310021, China
  • Received:2025-01-18 Published:2026-05-25 Online:2026-06-02

摘要:

以水稻秸秆为原料,分别以尿素和碳酸氢钠为氮源和化学活化剂,制备基于碳酸氢钠活化的氮掺杂水稻秸秆生物炭,开展生物炭吸附溶液中镉离子(Cd2+)的系列实验,研究溶液pH值、生物炭添加量、溶液中Cd2+初始质量浓度、温度、离子强度、共存离子等对生物炭吸附溶液中Cd2+的影响,并从动力学角度探究生物炭吸附Cd2+的机制。结果表明,尿素掺杂和碳酸氢钠活化的共同作用,提高了生物炭对Cd2+的吸附性能。相较于未改性的水稻秸秆生物炭(BC),将水稻秸秆粉、碳酸氢钠、尿素以2∶1∶1的比例改性制备的生物炭BC2-1-1对Cd2+的饱和吸附量为45.322 6 mg·g-1,是BC的5.27倍。生物炭对Cd2+的等温吸附行为符合朗缪尔(Langmuir)等温吸附模型,动力学行为符合准二级动力学方程,说明是以化学吸附为主导的单分子层吸附机制。研究结果可为水稻秸秆的高值化利用和镉污染水体的修复提供理论依据和技术支撑。

关键词: 水稻秸秆生物炭, 氮掺杂, 化学活化, 镉, 吸附

Abstract:

Nitrogen-doped rice straw biochar activated by sodium bicarbonate was prepared using rice straw as the biomass precursor, with urea and sodium bicarbonate serving as the nitrogen source and chemical activator, respectively. A series of adsorption experiments were conducted to investigate the cadmium ions (Cd2+) adsorption in aqueous solutions using the prepared rice straw biochar. The effects of various factors, including solution pH value, biochar addition amount, initial Cd2+ mass concentration in solution, temperature, ionic strength and coexisting ions, on the adsorption performance were systematically examined. Additionally, the adsorption mechanism was explored from the kinetic perspective. The results demonstrated that the combined effect of urea doping and sodium bicarbonate activation enhanced Cd2+ adsorption. Compared with the conventional rice straw biochar (BC), the biochar prepared with a mixing ratio of 2∶1∶1 for rice straw powder, sodium bicarbonate and urea (marked as BC2-1-1) exhibited a maximum Cd2+ adsorption capacity of 45.322 6 mg·g-1, which was 5.27 times as that of BC. The adsorption of Cd2+ by biochar fitted well with the Langmuir isothermal adsorption model, and followed the pseudo-second-order kinetic equation, indicating a monolayer adsorption mechanism dominated by chemical adsorption. This study provided theoretical basis and technical support for the high-value utilization of rice straw and the remediation of cadmium-contaminated water.

Key words: rice straw biochar, nitrogen doping, chemical activation, cadmium, adsorption

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