Exploring the interactions and binding sites between Cd and functional groups in soil using two-dimensional correlation spectroscopy and synchrotron radiation based spectromicroscopies

[Display omitted] •The interactions and binding between Cd and functional groups are essential for their fates.•Two-dimensional correlation spectroscopy can identify Cd binding to functional groups in soils.•Synchrotron radiation based spectromicroscopy shows the micro-scale distribution of Cd in soils.•Soil functional groups controlling Cd binding can be modified by fertilization treatments. 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