title: The role of Fe(III) on phosphate released during the photo-decomposition of organic phosphorus in deionized and natural waters.
abstract: The photo-decomposition of organic phosphorus is an important route for the phosphorus cycle by which phosphate is regenerated in the aquatic environment. In this study, the role of Fe3+as a natural photosensitizer toward the decomposition of organic phosphorus to release phosphate was examined in deionized and natural waters under UV and sunlight irradiation using glyphosate as the organic phosphorus model. The results showed that the concentration of glyphosate decreased with irradiation time in the Fe3+/UV and Fe3+/sunlight systems and TOC gradually decreased, which confirmed that glyphosate was degraded by Fe3+. The amount of phosphate released from the photo-decomposition of glyphosate was higher in the presence of Fe3+than that of the control experiment under UV and sunlight irradiation conditions, and the generation rate of phosphate also increased with increasing Fe3+concentrations. The formation of hydroxyl radicals (·OH) in the Fe3+/UV and Fe3+/sunlight systems was identified according to the photoluminescence spectra (PL) using coumarin as the trapping molecule, and the steady-state concentrations of ·OH for the Fe3+/UV and Fe3+/sunlight systems were 1.06 × 10-14M and 0.09 × 10-14M, respectively. When natural water was spiked with glyphosate and Fe3+, the phosphate that was released in the Fe3+was higher than that of the control, and the phosphate that was released was inhibited when isopropanol was added to the reaction. All of these results demonstrate that the photochemical activity of Fe3+has significantly impact in the release of phosphate from the photo-decomposition of organic phosphorus.
authors: Lab of Eco-Environmental Engineering Research, College of Resources & Environment, Huazhong Agriculture University, Wuhan 430070, China.
authors: Yongcan
authors: Y
authors: Jiang
authors: Lab of Eco-Environmental Engineering Research, College of Resources & Environment, Huazhong Agriculture University, Wuhan 430070, China.
authors: Naixin
authors: N
authors: Kang
authors: Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China.
authors: Yiyong
authors: Y
authors: Zhou
authors: Lab of Eco-Environmental Engineering Research, College of Resources & Environment, Huazhong Agriculture University, Wuhan 430070, China; Institute of Hydrobiology, The Chinese Academy of Sciences, Wuhan 430072, China. Electronic address: liugl@mail.hzau.edu.cn.
authors: Guanglong
authors: G
authors: Liu
authors: Lab of Eco-Environmental Engineering Research, College of Resources & Environment, Huazhong Agriculture University, Wuhan 430070, China.
authors: Duanwei
authors: D
authors: Zhu
mesh_terms: D005290:Ferric Compounds / Q000737:chemistry*; D005998:Glycine / Q000031:analogs & derivatives / Q000737:chemistry; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D017665:Hydroxyl Radical / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D010100:Oxygen / Q000737:chemistry; D010710:Phosphates / Q000737:chemistry; D010758:Phosphorus / Q000737:chemistry*; D055668:Photochemical Processes; D013472:Sunlight; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry*; D000097797:Glyphosate
chemical_list: D005290:Ferric Compounds; D005998:Glycine; D006812:Humic Substances; D017665:Hydroxyl Radical; D007501:Iron; D010100:Oxygen; D010710:Phosphates; D010758:Phosphorus; D014867:Water; D000097797:Glyphosate
keywords: Fe(3+); Glyphosate; Hydroxyl radicals; Natural water; Phosphate