DISTRIBUTION CHARACTERISTICS OF NITROGEN AND PHOSPHORUS IN SOIL MEDIUM LAYER IN DIFFERENT TYPES OF BIORETENTION FACILITIES
To explore the accumulation of nitrogen and phosphorus in bioretention facilities in practical projects,four types of typical bioretention facilities in the Yuelai Sponge City in Chongqing were taken as research objects to investigate the contents of TN,NH4-N,NO3--N,TP and available phosphorus(AP)at different depths of soil media,and study the distribution of nitrogen and phosphorus in the medium layer.The results showed that the contents of TN and TP in the surface soil(0 to 10 cm)of ecological tree pond,rain garden,biological retention zone and biological parterre were the highest.In particular,the contents of TN in the surface soil of rain gardens were the highest,reaching 885 mg/kg.NH4+-N was mainly distributed in the middle layer of soil,accounting for about 28％of the total content.NO3--N content in different soil layers had little difference and fluctuated in the range of 0.31～1.25 mg/kg.Water content(WC)can affect the distribution of NO3--N and AP in soil,and NO3--N content in the middle and upper soil of ecological tree pool was significantly negatively correlated with WC at the level of 0.05,and higher water content can weaken the accumulation of NO3--N.pH effected the distribution of NO3--N,TP,TN and AP in soil,and the contents of AP and NO3--N in soil were negatively correlated with pH.Higher pH can reduce the accumulation of NO3--N and AP in soil.
nitrogen and phosphorus concentrationsbioretention facilitydistribution characteristicssoil mediumwater content
NETL
NSTL
万方数据
