原位洗脱技术对凉水河底泥中氮、磷释放特征的影响

Effect of in-situ physical elution technology on release features of nitrogen and phosphorus in the sediment of Liangshui river

为探讨新兴底泥原位修复技术-原位洗脱技术对城市河流凉水河底泥中氮、磷释放的抑制作用,于现场采集洗脱前后样品并设计室内静态模拟实验,分析了实验期间洗脱组和对照组上覆水中NH4^+-N、NO^3--N、TN、PO4^3--P、TP浓度和释放速率变化特征。结果表明:洗脱组释放第30天时,NH4+-N由底泥向上覆水中平均NH4^+-N平均浓度为0.52 mg·L^-1,较对照组下降了89.4%;PO4^3--P和TP平均释放速率较对照组降低了78.1%和83.0%,上覆水中TP平均浓度为0.22 mg·L^-1,较对照组下降了68.1%。原位洗脱技术对底泥中NH4^+-N、PO4^3--P释放的抑制作用主要通过对有机氮、磷物质的削减和水-沉积物界面还原环境的改善来实现。

In this study,a new in-situ remediation technology-in-situ physical elution technology was used to conduct the inhibition experiments on nitrogen and phosphorus release from the sediment of Liangshui River.The in-situ samples before and after elution were collected,then the lab static simulation tests were also NH4^+-N,overlying water of the elution group and control group were analyzed.The results were showed that for the NH4^+-N release rate from sediment to the overlying water was(-6.51±0.32)NH4^+-N concentration in the overlying water PO4^3--P and TP release rates decreased by 78.1%and 83.0%compared to the control group,respectively.The average TP concentration in the overlying water reached 0.22 mg·L^-1,which was 68.1%lower than the control group.The NH4^+-N and realized through the reduction of organic nitrogen and phosphorus substances and the amelioration of reducing environments in water-sediment interface.