Copper binding to soil fulvic and humic acids: NICA-Donnan modeling and conditional affinity spectra

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	Copper binding to soil fulvic and humic acids: NICA-Donnan modeling and conditional affinity spectra
	Jinling Xu 1; Wenfeng Tan 1,2; Juan Xiong 2; Mingxia Wang 2; Linchuan Fang 1; Luuk K. Koopal 2,3
刊名	Journal of Colloid and Interface Science
	2016-04-01
通讯作者邮箱	flinc629@hotmail.com
期号	473 页码:141-151
关键词	Humic substance Humic acid Fulvic acid Cu binding NICA-Donnan model
通讯作者	Linchuan Fang
英文摘要	Conditional affinity spectrum underlying NICA isotherm provides practical insight into the characteristics of metal ions binding to HS at constant environmental conditions. The distributions of binding affinity for bound species are estimated. Carboxylic groups make the main contributions to Cu binding to HS. For JLHA with relatively high amount of carboxylic groups, the occupation of phenolic type sites by Cu can be negligible. Phthalate-type structure is more probable for Cu binding to JLHA. There is a non-negligible amount of phenolic-Cu on JGHA, which increases the chance of forming more stable complexes.Binding of Cu(II) to soil fulvic acid (JGFA), soil humic acids (JGHA, JLHA), and lignite-based humic acid (PAHA) was investigated through NICA-Donnan modeling and conditional affinity spectrum (CAS). It is to extend the knowledge of copper binding by soil humic substances (HS) both in respect of enlarging the database of metal ion binding to HS and obtaining a good insight into Cu binding to the functional groups of FA and HA by using the NICA-Donnan model to unravel the intrinsic and conditional affinity spectra. Results showed that Cu binding to HS increased with increasing pH and decreasing ionic strength. The amount of Cu bound to the HAs was larger than the amount bound to JGFA. Milne’s generic parameters did not provide satisfactory predictions for the present soil HS samples, while materialspecific NICA-Donnan model parameters described and predicted Cu binding to the HS well. Both the ‘low’ and ‘high’ concentration fitting procedures indicated a substantial bidentate structure of the Cu complexes with HS. By means of CAS underlying NICA isotherm, which was scarcely used, the natureof the binding at different solution conditions for a given sample and the differences in binding mode were illustrated. It was indicated that carboxylic group played an indispensable role in Cu binding to HS in that the carboxylic CAS had stronger conditional affinity than the phenolic distribution due to its large degree of proton dissociation. The fact was especially true for JGFA and JLHA which contain much larger amount of carboxylic groups, and the occupation of phenolic sites by Cu was negligible. Comparable amounts of carboxylic and phenolic groups on PAHA and JGHA, increased the occupation of phenolic type sites by Cu. The binding strength of PAHA-Cu and JGHA-Cu was stronger than that of JGFA-Cu and JLHA-Cu. The presence of phenolic groups increased the chance of forming more stable complexes, such as the salicylate-Cu or catechol-Cu type structures.
收录类别	SCI
原文出处	http://www.sciencedirect.com/science/article/pii/S0021979716302077
语种	英语
WOS记录号	WOS:000375168200018
内容类型	期刊论文
源URL	[http://ir.iswc.ac.cn/handle/361005/7754]
专题	水土保持研究所_水保所科研产出--SCI_2016--SCI
作者单位	1.State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Institute of Soil and Water Conservation, Chinese Academy of Sciences and the Ministry of Water Resources, Yangling, Shaanxi Province 712100, PR China 2.College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China 3.Physical Chemistry and Soft Matter, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
推荐引用方式 GB/T 7714	Jinling Xu,Wenfeng Tan,Juan Xiong,et al. Copper binding to soil fulvic and humic acids: NICA-Donnan modeling and conditional affinity spectra[J]. Journal of Colloid and Interface Science,2016(473):141-151.
APA	Jinling Xu,Wenfeng Tan,Juan Xiong,Mingxia Wang,Linchuan Fang,&Luuk K. Koopal.(2016).Copper binding to soil fulvic and humic acids: NICA-Donnan modeling and conditional affinity spectra.Journal of Colloid and Interface Science(473),141-151.
MLA	Jinling Xu,et al."Copper binding to soil fulvic and humic acids: NICA-Donnan modeling and conditional affinity spectra".Journal of Colloid and Interface Science .473(2016):141-151.