排水沟渠炉渣与底泥对水中氮、磷截留效应

通过等温热力学吸附实验,将炉渣、炉渣+30%底泥、排水沟渠底泥对水中氨氮的去除效果进行比较,并采用Langmuir等温吸附方程对3种基质吸附氨氮、磷酸盐的量进行拟合;通过动力学实验,比较3种基质吸附速率.结果表明,炉渣、炉渣+30%底泥、排水沟渠底泥对氨氮的最大吸附量分别为0.49,1.03,1.75mg/g,对磷酸盐的最大吸附量分别为0.99,2.33,1.88mg/g;4h内基质吸附氨氮速率分别为:0.10,0.11,0.54mg/(g·h),2h内基质吸附磷酸盐速率分别为:0.048,0.051,0.096mg/(g·h).由于沟渠底泥较为松散、遇水冲刷易流失,故选择炉渣作为沟渠基质坝的填充物.基质坝能够减缓渠水流速,延长渠水的水力停留时间(HRT).

Interception effect of ditch slag and sediments on nitrogen and phosphorus in water

In order to discuss the adsorption capacity of nitrogen and phosphorus for slag, 70% slag with 30% ditch sediment and ditch sediments, the isothermal adsorption and kinetics experiments were conducted at the comprehensive experimental field of the Sanjiang Mire Wetland Experimental Station(47°35￠N, 133°31￠E), Chinese Academy of Sciences. Meanwhile, the experimental data were fitted by the Langmuir isothermal adsorption equation. The maximum ammonium nitrogen adsorption amounts for slag, 70% slag with 30% ditch sediment, and ditch sediments were 0.49, 1.03and 1.75mg/g, respectively; the maximum phosphate adsorption amounts were 0.99, 2.33and 1.88mg/g, respectively; the adsorption rates of ammonium nitrogen were 0.10, 0.11and 0.54mg/(g·h) during 0~4h; the adsorption rates of phosphate were 0.048, 0.051, 0.096mg/(g·h) during 0~2h. Slag was used as matrix dam fill since ditch sediments were loose and easy to run off. The hydraulic retention time of ditch water in drainage ditches was extended with matrix dams as well as mitigating the flow velocity of ditch water.