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生物炭胶体凝聚的离子特异性效应

Ion Specific Effects on Biochar Colloid Aggregation

魏自冕, 夏金玉, 刘剑伟, 王阳, 赵顺阳, 朱龙辉

Environment and Resource / 2026,8(2): 273-279 / 2026-06-18 8 17

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• Information:

  重庆科技大学化学化工学院，重庆

• Keywords:
  Biochar colloids; Dynamic light scattering; Aggregation kinetics; Critical coagulation concentration; Ionspecific effects
  生物炭胶体; 动态光散射; 凝聚动力学; 临界聚沉浓度; 离子特异性效应
• Abstract: Biochar, as an environmentally friendly material, is widely used in soil remediation and other fields. The aggregation and dispersion behavior of biochar colloids formed during environmental aging has an important impact on the application efficacy and potential risks of biochar in soil. The ion-specific effect refers to the different properties exhibited by different ions, especially ions of the same valence, in different systems, such as colloid aggregation/ dispersion behavior, interfacial adsorption characteristics, and particle surface potential. However, current research on the ion-specific effects of alkali metal ions on the aggregation behavior of biochar colloids is limited, and their microscopic mechanisms remain unclear. In this study, peanut shell biochar was used as the research object. The hydrodynamic diameter, critical coagulation concentration (CCC), and zeta potential of biochar colloids were measured in KNO3，NaNO3 and LiNO3 solutions at different concentrations to investigate the influence of alkali metal ions on the aggregation kinetics of biochar colloids, and thereby elucidate the alkali metal ion-specific effects and the mechanisms of their differences. The results showed that the hydrodynamic diameter of biochar colloids increased significantly with increasing electrolyte concentration. The aggregation behavior of biochar colloids in the presence of different cations displayed obvious ion specificity. Specifically, the order of the critical coagulation concentration (CCC) for biochar colloid aggregation was: Li+ > Na+ > K+. By measuring the zeta potential of biochar colloid particles in different systems, it was demonstrated that ion-specific effects dominate the differences in ionic interfacial adsorption strength during the aggregation process of biochar colloids, which is the key factor responsible for the ion-specific regulation of biochar colloid aggregation by different ions. This directly confirms the regulatory role of ion-specific effects on the aggregation behavior of biochar colloids. The findings provide a theoretical basis for evaluating the environmental fate and practical application of biochar colloids. 生物炭作为一种环境友好型材料广泛应用于土壤改良等领域，其在环境中老化形成生物炭胶体的凝聚与分散行为对生物炭在土壤中的施用功效及潜在风险具有重要影响。离子特异性效应是指不同离子，特别是同价的不同离子在不同体系中产生不同的性质差异，比如胶体凝聚分散行为、界面吸附特征及颗粒表面电位等。然而，目前针对碱金属离子对生物炭胶体凝聚行为的离子特异性效应研究较少，其微观机制尚不明确。本文以花生壳生物炭为研究对象，通过测定生物炭胶体在不同浓度的KNO3、NaNO3和LiNO3溶液下的水动力学直径、临界聚沉浓度（CCC）及Zeta电位，探究碱金属离子对生物炭胶体凝聚动力学过程的影响，进而阐明碱金属离子特异性效应及差异机制。研究发现，随着电解质浓度的增加，生物炭胶体的水动力学直径显著增大；不同阳离子作用下生物炭胶体的凝聚行为表现出明显的离子特异性，具体表现为：生物炭胶体凝聚的临界聚沉浓度（CCC）的大小顺序为：Li+>Na+>K+；通过测定不同体系下生物炭胶体颗粒Zeta电位，证明离子界面吸附强度差异由离子特异性效应主导，是造成不同离子调控生物炭胶体凝聚差异的关键因素。直观印证了离子特异性效应对生物炭胶体凝聚行为的调控作用。研究结果可为评估生物炭胶体的环境归趋及实际应用提供理论依据。
• DOI: 10.35534/er.0802037 (registering DOI)
• Cite: 魏自冕，夏金玉，刘剑伟，等．生物炭胶体凝聚的离子特异性效应［J］．环境与资源，2026，8（2）：273-279.