title: Effects of polyphosphates and orthophosphate on the dissolution and transformation of ZnO nanoparticles.
abstract: The fate and toxicity of zinc oxide nanoparticles (ZnO NPs) in nature are affected by solution chemistry such as pH, anions, and natural organic matter (NOM). Inorganic polyphosphates are environmentally ubiquitous phosphorus (P) species that may change the speciation and environmental fate of ZnO NPs. In this study, the interactions of polyphosphates with ZnO NPs and the impacts on ZnO NP dissolution and transformation were investigated and compared with orthophosphate (P1). The results revealed that pyrophosphate (P2), tripolyphosphate (P3), and hexametaphosphate (P6) enhanced whereas P1inhibited the dissolution of ZnO NPs. In addition, P1, P2, and P3promoted the transformation of ZnO NPs into zinc phosphate (Zn-P) precipitates via interactions with dissolved Zn2+. However, P6-promoted ZnO NP dissolution was through the formation of soluble Zn-P complexes due to the strong capability of P6to chelate with Zn2+. The transformation of ZnO NPs in the presence of P3was affected by reaction time, pH, and P/Zn molar ratio. P3first formed inner-sphere surface complexes on ZnO NPs, which gradually transformed into crystalline Zn2HP3O10(H2O)6precipitates. This study provided a new perspective for understanding the reactivity of various forms of inorganic phosphate species with ZnO NPs in the natural environment.
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Biao
authors.initials: B
authors.lastname: Wan
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Yupeng
authors.initials: Y
authors.lastname: Yan
authors.affiliation: School of Earth and Atmospheric Sciences, Georgia Institute of Technology, 311 Ferst Dr, Atlanta, GA 30324-0340, USA.
authors.forename: Yuanzhi
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Yuge
authors.initials: Y
authors.lastname: Bai
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Fan
authors.initials: F
authors.lastname: Liu
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Wenfeng
authors.initials: W
authors.lastname: Tan
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Qiaoyun
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: fxh73@mail.hzau.edu.cn.
authors.forename: Xionghan
authors.initials: X
authors.lastname: Feng
mesh_terms: D011232:Chemical Precipitation; D053758:Nanoparticles / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011122:Polyphosphates / Q000737:chemistry*; D012995:Solubility; D017967:Zinc Compounds; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D010710:Phosphates; D011122:Polyphosphates; D017967:Zinc Compounds; C005035:hexametaphosphate; C043952:zinc phosphate; C005692:triphosphoric acid; D015034:Zinc Oxide
keywords: Dissolution; Natural environment; Orthophosphate; Polyphosphates; Transformation; ZnO nanoparticles