摘要
采用荧光光谱、红外光谱、平行因子(PARAFAC)分析及二维相关光谱(2D-COS)分析来解释Fe(Ⅲ)与牛粪发酵DOM的络合异质性及机制.结果表明,PAFAFAC能够识别6个荧光组分,包括类蛋白(C2)、类富里酸(C1)、类腐殖酸(C4、C5)、类蛋白与类富里酸和类腐殖酸结合的荧光组分(C3、C6).2D-SYS-COS分析仅能识别类蛋白和类富里酸荧光物质,DOM中类蛋白荧光为主要的荧光组分.2D-COS分析表明,在334nm处的类富里酸荧光组分优先与Fe(Ⅲ)离子发生络合作用,络合次序为334nm→306nm.DOM中能够优先与Fe(Ⅲ)发生络合作用的为仲铵盐−NH_(2)基团,各官能团组分与Fe(Ⅲ)发生络合作用次序为2265→2771→1528→1310→1805→1479cm^(-1).双对数模型计算结果表明牛粪发酵沼液DOM能够与Fe(Ⅲ)形成高化学稳定性的络合物,其络合常数在4.34~7.03之间,研究结果能够为沼液施用土壤金属离子的形态分布和迁移转化提供理论指导.
In this work,the binding heterogeneities and mechanism of Fe(Ⅲ)with digestate dissolved organic matter(DOM)derived from anaerobic fermentation of cow manure was investigated through fluorescence spectra,Fourier Transform Infrared spectroscopy(FTIR),parallel factor analysis(PARAFAC)and two-dimensional correlation spectroscopy(2D-COS).The results showed that six fluorescent components,including protein-like(C2),fulvic-like(C1),humic-like(C4 and C5),a combination of protein-like and fulvic-like(C3),a combination of protein-like and humic-like(C6)could be identified by PARAFAC model.However,only protein-like and fulvic-like components could be identified by 2D-SYS-COS,and protein-like were dominant fluorescent component in DOM.2D-COS analysis revealed that fulvic-like substances showed a preferential affinity with Fe(Ⅲ)at 334nm,and the preferential bonding followed the order:334nm→306nm.The−NH_(2) group of secondary ammonium could preferentially combine with Fe(Ⅲ),and the preferential binding of Fe(Ⅲ)to the digestate DOM followed the order:2265→2771→1528→1310→1805→1479cm^(-1).The results of double log equation indicated that highly chemically stable DOM-Fe(Ⅲ)complexes could be formed,whose logarithmic conditional stability ranged from 4.34 to 7.03.The work herein could provide a theoretical guide for the species distribution,migration and transformation of metal ions when digestate was applied to soils.
作者
刘玉丹
谢鑫
谢莉鸿
田媛媛
杨梦
郭旭晶
LIU Yu-dan;XIE Xin;XIE Li-hong;TIAN Yuan-yuan;YANG Meng;GUO Xu-jing(College of Resources and Environment,Chengdu University of Information Technology,Chengdu 610225,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2021年第2期771-777,共7页
China Environmental Science
基金
国家自然科学基金资助项目(41503110)
四川省科技重大专项资助(2018SZDZX0024)。
关键词
发酵沼液
DOM
络合
平行因子分析
二维相关光谱
digestate
DOM
complexation
parallel factor analysis
two-dimensional correlation spectroscopy
