Impact of biochar colloids on thallium(I) transport in water-saturated porous media: Effects of pH and ionic strength.
Impact of biochar colloids on thallium(I) transport in water-saturated porous media: Effects of pH and ionic strength.
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DOI：
10.1016/j.chemosphere.2022.137152
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发表时间：
2022-11
期刊：
影响因子：
8.8
通讯作者：
Yu Cao-;Chengxue Ma;Jinni Yao;Wanpeng Chen;Li-Chuan Gu;Hongxia Liu;Caihong Liu;Jiaming Xiong
中科院分区：
文献类型：
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作者：
Yu Cao-;Chengxue Ma;Jinni Yao;Wanpeng Chen;Li-Chuan Gu;Hongxia Liu;Caihong Liu;Jiaming Xiong
了解铊 (TI) 在地下环境中的迁移行为对于预防铊污染至关重要。随着生物炭的广泛生产和利用，生物炭胶体携带环境污染物的显着能力可能使这些胶体对 Tl(I) 迁移率变得重要。本研究系统地研究了木材来源的生物炭 (WB) 和玉米秸秆来源的生物炭 (CB) 胶体在不同 pH（5、7 和 10）和离子强度 (IS)（1、5 和 50 mM NaNO3）下对水饱和多孔介质中 Tl(I) 传输的影响。由于生物炭的吸附能力和沙子表面吸附位点的竞争，WB 胶体在 pH 7 的所有 IS 条件下改善了 Tl(I) 传输。然而，在 IS 50 mM 时，CB 胶体由于应变而略微阻碍了 Tl(I) 的迁移率。此外，WB 和 CB 胶体在 IS 5 mM 的所有 pH 条件下都能加速 Tl(I) 的迁移率。在pH 10时，由于含O官能团的去质子化和生物炭胶体的较高流动性，促进效果更加明显。此外，两位点非平衡模型和两位点动力学附着/脱离模型分别适当地描述了 Tl(I) 和生物炭胶体的突破曲线 (BTC)。胶体促进溶质转运模型还可以很好地描述生物炭胶体对 Tl(I) 转运的影响。这项研究深入了解了生物炭胶体存在下 Tl(I) 的迁移和命运。
Understanding the migration behavior of thallium (TI) in subsurface environments is essential for Tl pollution prevention. With the wide production and utilization of biochar, the notable ability of biochar colloids to carry environmental contaminants may make these colloids important for Tl(I) mobility. This study systematically investigated the impact of wood-derived biochar (WB) and corn straw-derived biochar (CB) colloids on Tl(I) transport in water-saturated porous media under different pH (5, 7 and 10) and ionic strengths (ISs) (1, 5 and 50 mM NaNO3). WB colloids improved Tl(I) transport under all IS conditions at pH 7 due to the adsorption capacity of biochar and competition for adsorption sites on the sand surface. However, at IS 50 mM, CB colloids slightly impeded Tl(I) mobility due to the straining. In addition, both WB and CB colloids accelerated Tl(I) mobility under all pH conditions at IS 5 mM. At pH 10, the promotion effect was more obvious due to the deprotonation of O-containing functional groups and higher fluidity of biochar colloids. Furthermore, the two-site nonequilibrium model and two-site kinetic attachment/detachment model suitably described the breakthrough curves (BTCs) of Tl(I) and biochar colloids, respectively. The colloid-facilitated solute transport model could also describe Tl(I) transport influenced by biochar colloids reasonably well. This study provides insight into the migration and fate of Tl(I) in the presence of biochar colloids.