Quantitative relationships between the adsorptivity of carbonaceous materials in soil for Pb(II) and soil organic matter content
Quantitative relationships between the adsorptivity of carbonaceous materials in soil for Pb(II) and soil organic matter content
复制标题
土壤中碳质材料对Pb(II)的吸附能力与土壤有机质含量的定量关系
DOI：
10.1016/j.scitotenv.2016.07.225
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发表时间：
2016-12-01
影响因子：
9.8
通讯作者：
Sheng, G. Daniel
中科院分区：
文献类型：
--
作者：
Li, Jianliang;He, Anfei;Sheng, G. Daniel
人造碳质材料（MCMs）的强吸附作用介导了土壤中重金属的吸附行为。由于土壤有机质（SOM）可以通过在mcm表面涂覆溶解性有机物（DOM）来改变mcm的吸附能力，因此实验室报道的mcm的吸附能力往往与其在土壤中的实际能力相偏离。认为SOM对土壤中MCM吸附性能的影响是通过SOM释放土壤溶液中的DOM， DOM随后结合到MCM上，从而改变MCM表面酸度，从而改变MCM对重金属的吸附能力。在这项研究中，我们首先从中国广泛地区收集的10种表土中提取DOM，这些表土具有广泛的SOM。然后用DOM溶液将DOM分别加载到四种mcm上，包括活性炭（AC）、多壁碳纳米管（MWCNT）和两种生物炭（BC400和BC700），共获得44个已知结合DOM量的MCM-DOM复合物样品。然后测定这些MCM-DOM复合物样品的表面酸度和对Pb（II）的吸附能力。我们发现DOM浓度与SOM含量、DOM结合到mcm与DOM浓度、MCM-DOM配合物的表面酸度与DOM结合到mcm之间、MCM-DOM配合物上的Pb（II）吸附与MCM-DOM配合物的表面酸度之间存在显著的相关性。在了解了这些单独的线性关系后，通过结合单独的相关性并直接绘制前者与后者之间的关系，建立了Pb（II）吸附与SOM含量之间的线性关系。这些关系可以通过测定土壤有机质来准确预测mcm对土壤中重金属的吸附能力。(C) 2016 Elsevier B.V.版权所有
Strong adsorptivity of manufactured carbonaceous materials (MCMs) mediates the behavior of heavy metals in soil. Laboratory-reported adsorptivity of MCMs often deviates from their actual abilities in soil, because soil organic matter (SOM) can change the adsorptive abilities of MCMs by coating dissolved organic matter (DOM) on the surface of the MCMs. It was considered that the influence of SOM on the adsorptivity of MCMs in soil follows a sequential pathway of SOM releasing DOM in soil solution and subsequent DOM binding onto MCMs, thereby altering MCM surface acidity and hence changing MCM adsorptivity for heavy metals. In this study, we first extracted DOM from ten topsoils collected over a broad region of China with a wide range of SOM. The DOM solutions were then used to load DOM onto four MCMs including activated carbon (AC), multiwalled carbon nanotube (MWCNT), and two biochars (BC400 and BC700), respectively, obtaining a total of 44 MCM-DOM complex samples with known amounts of bound DOM. These MCM-DOM complex samples were then determined for their surface acidities and adsorptive abilities for Pb(II). We found that there were significant correlations between DOM concentration and SOM content, between DOM binding onto MCMs and DOM concentration, between surface acidity of MCM-DOM complexes and DOM binding onto MCMs, as well as between Pb(II) adsorption on MCM-DOM complexes and surface acidity of MCM-DOM complexes. With understanding of these individual linear correlations, linear relationships between the Pb(II) adsorption and SOM content were established by combining individual correlations and by directly plotting the former against the latter. These relationships may be used to accurately predict the adsorptive abilities of MCMs for heavy metals in soils via simply determining SOM. (C) 2016 Elsevier B.V. All rights reserved.