title: Exploring the interactions and binding sites between Cd and functional groups in soil using two-dimensional correlation spectroscopy and synchrotron radiation based spectromicroscopies.
abstract: Understanding how heavy metals bind and interact in soils is essential for predicting their distributions, reactions and fates in the environment. Here we propose a novel strategy, i.e., combining two-dimensional correlation spectroscopy (2D COS) and synchrotron radiation based spectromicroscopies, for identifying heavy metal binding to functional groups in soils. The results showed that although long-term (23 yrs) organic fertilization treatment caused the accumulation of Cd (over 3 times) in soils when compared to no fertilization and chemical fertilization treatments, it significantly (p<0.05) reduced the Cd concentration in wheat grain. The 2D COS analyses demonstrated that soil functional groups controlling Cd binding were modified by fertilization treatments, providing implications for the reduced bioavailability of heavy metals in organic fertilized soils. Furthermore, correlative micro X-ray fluorescence spectromicroscopy, electron probe micro-analyzer mapping, and synchrotron-radiation-based FTIR spectromicroscopy analysis showed that Cd, minerals, and organic functional groups were heterogeneously distributed at the micro-scale in soil colloids. Only minerals, rather than organic groups, had a similar distribution pattern with Cd. Together, this strategy has a potential to explore the interactions and binding sites among heavy metals, minerals and organic components in soil.
authors.affiliation: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization and National Engineering Research Center for Organic-Based Fertilizers, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China; Department of Soil Science, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Fusheng
authors.initials: F
authors.lastname: Sun
authors.affiliation: Department of Soil Science, North Carolina State University, Raleigh, NC 27695, USA.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Polizzotto
authors.affiliation: Key Laboratory of Surficial Geochemistry, Ministry of Education, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210026, China.
authors.forename: Dongxing
authors.initials: D
authors.lastname: Guan
authors.affiliation: College of Environment, Zhejiang University of Technology, Hangzhou 310014, PR China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization and National Engineering Research Center for Organic-Based Fertilizers, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Qirong
authors.initials: Q
authors.lastname: Shen
authors.affiliation: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization and National Engineering Research Center for Organic-Based Fertilizers, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Ran
authors.affiliation: Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
authors.forename: Boren
authors.initials: B
authors.lastname: Wang
authors.affiliation: Jiangsu Provincial Key Lab for Organic Solid Waste Utilization and National Engineering Research Center for Organic-Based Fertilizers, College of Resources & Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: yuguanghui@njau.edu.cn.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Yu
keywords: Cadmium; Long-term fertilization experiment; Soil; Synchrotron-radiation-based spectromicroscopy; Two-dimensional correlation spectroscopy