Application of diffusive gradients in thin-films technique for speciation, bioavailability, modeling and mapping of nutrients and contaminants in soils

Soil plays an important role in controlling the biogeochemical cycling of nutrients and contaminants in the environment. Reliable analytical techniques are critical to better understand their transformation in soils. Diffusive Gradients in Thin-films technique (DGT) is one of such techniques, which has become increasingly popular in soil research since 1998. Undeniably, DGT attracts increasing attentions from multidisciplinary researchers worldwide. This is mainly due to its inherent merits, including ease of use, in situ measurement, and biomimetic applications. Further, four important aspects of DGT applications in soil research were summarized. They include: 1) chemical speciation, 2) bioavailability measurement, 3) desorption kinetic modeling, and 4) interfacial process mapping of nutrients and contaminants, with main focus on the progresses achieved during the past five years. In short, DGT is effective in studying the biochemical behaviors of nutrients (e.g., phosphate and nitrate), trace elements (e.g., Cd, Ni, Zn, Cu, Pb, and As), and polar organic compounds (e.g., antibiotics, pesticides, and bisphenols) in soils. Toward the end, we proposed several aspects of applying DGT as a versatile tool in soil research.