Abstract
This study examined five ponds and three ditches in the Shufengwan Sports Park in a new urban district of Hefei City, from which surface-layer sediments and overlying water samples were collected during autumn, winter, and summer. The equilibrium phosphate concentrations (EPC0) of the sediments and its response to exogenous carbon or nitrogen were then measured. The resulting EPC0values were used to assess the risk of phosphorus release by the sediments. Finally, major factors influencing phosphorous release were identified using the Partial Least Squares Regression (PLSR) method. The sediments in the urban park exhibited a light-to-moderate level of phosphorous pollution, with the total phosphorus content (TP) ranging from 209.28 to 713.51 mg·kg-1 and biologically available phosphorus accounting for 18.51%-36.21% of the total phosphorus content. Under ambient background, the EPC0 values in pond sediments were 0.012-0.142 mg·L-1, with a mean value of 0.057 mg·L-1, while in ditches the values ranged from 0.036 to 0.156 mg·L-1 with an average value of 0.078 mg·L-1. The addition of exogenous carbon increased the EPC0 values (by approximately 47.5% in pond 3), and thus increased the risk of phosphorus release from sediments, in pond 1, 3, and ditch 1. However, EPC0 values of the other ponds and ditches decreased (in particular, by approximately 58.6% in pond 5), indicating that the risk of phosphorus release decreased. After the addition of exogenous nitrogen, the EPC0 values of almost all ponds and ditches declined to varying degrees (except in ditches 1 and 2 during the summer). In particular, in the EPC0 value of pond 2 declined by approximately 51.6%. The declining values imply that nitrogen was a limiting factor in phosphorus uptake by sediments in ponds and ditches. According to the results of PLSR, nitrogen and phosphorus had different effects on the EPC0 values of sediments in ponds and ditches.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
