微生物残体及其与矿物形成的复合体对Pb^(2+)的吸附解吸  

Adsorption and desorption of Pb^(2+) by microbial necromass and microbial-mineral complexes

作　　者：雷梣岑 杨时玲 张玉[1] 李宇轩 常婧 李芳芳[1] LEI Chencen;YANG Shiling;ZHANG Yu;LI Yuxuan;CHANG Jing;LI Fangfang(Yunnan Provincial Key Lab of Soil Carbon Sequestration and Pollution Control,Faculty of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming,650500,China)

机构地区：[1]云南省土壤固碳与污染控制重点实验室,昆明理工大学环境科学与工程学院,昆明650500

出　　处：《环境化学》2025年第3期939-948,共10页Environmental Chemistry

基　　金：国家自然科学基金(42167030,41907300);云南省重大科技项目(202202AG050019);云南省科技计划项目基础研究专青年(202001AU070088)资助.

摘　　要：土壤有机质是控制土壤重金属吸附行为的重要组分之一,最近微生物源有机质被认为是土壤稳态碳的重要组分,然而,微生物源有机质及其与土壤矿物形成的复合体对重金属的吸附解吸行为关注较少.以微生物(细菌、真菌)为有机质,黏土矿物(蒙脱石、赤铁矿)为矿物基质,制备细菌残体(BN)、真菌残体(FN)、细菌-蒙脱石复合体(B-M)、真菌-蒙脱石复合体(F-M)、细菌-赤铁矿复合体(B-Fe)、真菌-赤铁矿复合体(F-Fe),研究微生物残体及复合体对铅离子(Pb^(2+))的吸附解吸过程.结果表明,真菌残体和细菌残体具有相近的元素组成和有机官能团,其对Pb^(2+)的吸附解吸相一致;但相比于微生物-矿物复合体而言,纯残体对Pb^(2+)的吸附量较大,解吸率也较大,吸附并不稳定.各个复合体中,尽管赤铁矿-微生物复合体对Pb^(2+)的吸附量较蒙脱石-微生物复合体更小,但经比表面积标准化后,蒙脱石-微生物复合体的吸附明显降低,而赤铁矿-微生物复合体的吸附量前后变化不明显且高于蒙脱石组,表明赤铁矿-微生物复合体在单位面积的吸附能力高于蒙脱石-微生物复合体.真菌-矿物复合体较细菌-矿物复合体具有更高的吸附,经比表面积标准化后,真菌-矿物复合体仍具有更高的吸附.同时,各个复合体对Pb^(2+)的解吸率表现为B-M>B-Fe>F-M>F-Fe,表明赤铁矿-微生物复合体通过络合作用对Pb^(2+)的吸附更稳定,真菌-矿物复合体通过更强的阳离子-π作用和络合作用对Pb^(2+)的吸附更稳定.因此,微生物与矿物形成的复合体对Pb^(2+)的吸附能力在土壤重金属修复治理中需要被关注,这为控制土壤重金属的迁移和生物有效性提供了新的思路.Soil organic matter(SOM)is one of the important components controlling the adsorption behavior of heavy metals in soil.However,as an important component of stabilized SOM,little attention has been paid to the adsorption/desorption behavior of heavy metals by microbial-derived organic matter and its complexes formed with soil minerals.In this study,the adsorption/desorption of Pb ions(Pb^(2+))by microbial(bacteria and fungi)and the complexes with clay mineral(montmorillonite and hematite)were studied,specifically,bacterial necromass(BN),fungal necromass(FN),bacteria-montmorillonite complex(B-M),fungus-montmorillonite complex(F-M),bacteria-hematite complex(B-Fe),and fungus-hematite complex(F-Fe).The results showed that the fungal nacromass and bacterial necromass had similar elemental composition and organic functional groups,and their adsorption and desorption for Pb^(2+)were consistent.However,compared with the microbial-mineral complex,the microbial necromass has a larger adsorption capacity for Pb^(2+),the desorption rate is also larger,and the adsorption is not stable.In each complex,although the adsorption amount of Pb^(2+)by hematite-microbial complex was smaller than that of montmorillonitemicrobial complex,after the standardization of specific surface area,the adsorption of montmorillonite-microbial complex obviously decreased,while the adsorption of hematite-microbial complex did not change and was higher than that of montmorillonite group.The results showed that the adsorption capacity of hematite-microbial complex was higher than that of montmorillonitemicrobial complex.The adsorption of fungus-mineral complex was higher than that of bacteriamineral complex,and the adsorption of fungus-mineral complex was still higher after the standardization of specific surface area.Meanwhile,the desorption rate of Pb^(2+)for each complex was in order of B-M>B-Fe>F-M>F-Fe,indicating that the hematite-microbial complex was more stable for Pb^(2+)adsorption through complexation,and the fungus-mineral complex was more st

关 键 词：微生物残体 黏土矿物 吸附解吸 Pb^(2+) 

分 类 号：X-1[环境科学与工程] O6[理学—化学]