title: [Characteristics of phosphorus forms and the effects of UV light in the confluences water of Qujiang-Jialing River and Fujiang-Jialing River].
abstract: The confluences water of Qujiang-Jialing River and Fujiang-Jialing River was investigated in this paper for understanding the characteristics of phosphorus (P) forms and the effects of ultraviolet (UV) irradiation. Through analysis of P speciation, the results showed that the concentration of total P was above the Eutrophication threshold (0.2 mmol x m(-3)) in this study. Meanwhile, total dissolved P (TDP) and dissolved inorganic P (DIP) were the predominant forms of total P (TP) and TDP respectively at all sampling sites, which was independent of confluences. After confluences of Fujiang-Jialing River and Qujiang-Jialing River, the concentration of all forms of P in main stream increased, among which particulate P (PP) showed the greatest increase of up to 129%. Furthermore, water was fractionated by relative molecular weight (M(r)) of composition, and the results showed the predominant forms of dissolved P (DP, < 0.22 μm) was in the soluble high M(r) fraction (0.5 x 10(3)-10 x 10(3)), which was ranged from 47%-61% of DP. After confluences, no significant changes of P contents in different M(r) fraction of water were observed in the main stream (Jialing River). Moreover, UV irradiation experiment was conducted, and it suggested that P in free forms of water (< 0.5 x 10(3)) increased by 10% - 29%, as compared with the decreasing P in the other two M(r) fractions of M(r) 10 x 10(3)-0.22 μm and 0.5 x 10(3)-10 x 10(3). Additionally, in comparison with confluence site samples of Fujiang-Jialing River, the decreasing trend of P in colloid fraction (10 x 10(3)-0.22 μm) was higher in Qujiang-Jialing River. Thus, it confirmatively indicated that UV was an important environmental factor influencing the geochemical fate of P in aquatic system.
authors.forename: Jin-long
authors.initials: JL
authors.lastname: Yan
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.forename: Shi-qiang
authors.initials: SQ
authors.lastname: Wei
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Nian
authors.initials: N
authors.lastname: Guo
authors.forename: Lu-lu
authors.initials: LL
authors.lastname: Li
authors.forename: Jiang
authors.initials: J
authors.lastname: Liu
mesh_terms: D002681:China; D004784:Environmental Monitoring; D005068:Eutrophication; D010758:Phosphorus / Q000737:chemistry*; D045483:Rivers / Q000737:chemistry*; D014466:Ultraviolet Rays
chemical_list: D010758:Phosphorus