工业水处理 ›› 2025, Vol. 45 ›› Issue (11): 91-101. doi: 10.19965/j.cnki.iwt.2024-0908

• 试验研究 • 上一篇    下一篇

镁改性生物炭对工业废水中Pb(Ⅱ)和Cd(Ⅱ)的去除

王嘉宁(), 叶静怡, 包家华, 田凌志, 杨柳()   

  1. 兰州交通大学环境与市政工程学院 寒旱地区水资源综合利用教育部工程研究中心,甘肃 兰州 730070
  • 收稿日期:2025-02-28 出版日期:2025-11-20 发布日期:2025-11-20
  • 通讯作者: 杨柳
  • 作者简介:

    王嘉宁(2000— ),硕士,E-mail:

  • 基金资助:
    甘肃省教育厅高校科研创新平台重大培育项目(2024CXPT-14)

Removal of Pb(Ⅱ) and Cd(Ⅱ) from industrial wastewater by magnesium modified biochar

Jianing WANG(), Jingyi YE, Jiahua BAO, Lingzhi TIAN, Liu YANG()   

  1. Ministry of Education Engineering Research Center of Water Resource Comprehensive Utilization in Cold and Arid Regions, School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
  • Received:2025-02-28 Online:2025-11-20 Published:2025-11-20
  • Contact: Liu YANG

摘要:

以核桃青皮制备生物炭WGBC,然后以MgCl2为改性剂制备了一种镁改性生物炭(Mg-WGBC),用于去除工业废水中Pb(Ⅱ)和Cd(Ⅱ)。通过一系列表征分析了材料的表面形貌、孔径分布、官能团等理化特征,研究了温度、投加量、pH、共存离子等因素对Mg-WGBC吸附水中Pb(Ⅱ)和Cd(Ⅱ)效果的影响。结果显示,相比原始生物炭,Mg-WGBC有着更高的比表面积和更丰富的官能团结构;Mg-WGBC在较大pH范围内对Pb(Ⅱ)和Cd(Ⅱ)具有优异的去除效果;水中低价阳离子和SO4 2-对Mg-WGBC吸附Pb(Ⅱ)和Ca(Ⅱ)效果的影响较小,Al3+和Fe3+对吸附抑制作用较强;25 ℃下,Mg-WGBC投加0.15 g/L处理Pb(Ⅱ)废水和投加0.4 g/L处理Cd(Ⅱ)废水时,对Pb(Ⅱ)、Cd(Ⅱ)的平衡吸附量分别为331.164、118.259 mg/g。准二级反应动力学模型和Langmuir等温模型能较好地描述Mg-WGBC对Pb(Ⅱ)和Cd(Ⅱ)的去除过程,Mg-WGBC对Cd(Ⅱ)和Pb(Ⅱ)的吸附是通过化学作用的单层吸附,且是一个自发进行的放热过程。经过5次吸脱附循环后,Mg-WGBC对Pb(Ⅱ)和Cd(Ⅱ)的去除率仍可分别达到83.93%和81.95%。Mg-WGBC对Pb(Ⅱ)和Cd(Ⅱ)的去除受多种机制的影响,主要包括沉淀作用、离子交换、表面络合、静电吸引和阳离子-π相互作用。

关键词: 重金属废水, Pb, Cd, 改性生物炭, 吸附

Abstract:

To remove Pd(Ⅱ) and Cd(Ⅱ), a magnesium-modified biochar (Mg-WGBC) was prepared by magnesium chloride (MgCl2) modification with discarded walnut green husk biochar(WGBC). A series of characterization methods were employed to analyze the physicochemical properties, including surface morphology, pore size distribution, and functional groups. The effects of temperature, dosage, pH, and coexisting ions on the adsorption of Pb(Ⅱ) and Cd(Ⅱ) by Mg-WGBC were investigated. The results showed that, compared with pristine biochar, Mg-WGBC exhibited a higher specific surface area and a more abundant functional group structure. Mg-WGBC demonstrated exceptional removal efficiency for Pb(Ⅱ) and Cd(Ⅱ) over a wide pH range. The presence of low-valent cations and SO4 2- in water had minimal impact on the adsorption of Pb(Ⅱ) and Cd(Ⅱ) by Mg-WGBC, wheres Al3+ and Fe3+ exhibited significant inhibitory effects on the adsorption process. The maximum adsorption capacities of Mg-WGBC for Pb(Ⅱ) and Cd(Ⅱ) reached 331.164 mg/g and 118.259 mg/g, respectively, with dosages of 0.15 g/L for Pb(Ⅱ)-containing wastewater and 0.4 g/L for Cd(Ⅱ)-containing wastewater. The pseudo-second-order kinetic model and the Langmuir isotherm model could better describe the removal of Pb(Ⅱ) and Cd(Ⅱ) by Mg-WGBC. The adsorption of Pb(Ⅱ) and Cd(Ⅱ) on Mg-WGBC was a monolayer chemisorption process, which was a spontaneous and exothermic process. After five adsorption-desorption cycles, the removal rates of Pb(Ⅱ) and Cd(Ⅱ) by Mg-WGBC remained at 83.93% and 81.95%, respectively. The removal mechanisms of Pb(Ⅱ) and Cd(Ⅱ) by Mg-WGBC involved multiple processes, including precipitation, ion exchange, surface complexation, electrostatic attraction, and cation-π interactions.

Key words: heavy metal wastewater, Pb, Cd, modified biochar, adsorption

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