摘要
通过等温热力学吸附实验,比较人工湿地的基质高钙废渣、改性赤泥和火山石对污水中氨氮的去除效果。结果表明,3种基质的氨氮吸附过程都可以用Langmuir吸附等温方程进行拟合;高钙废渣、改性赤泥和火山石对氨氮的最大吸附量分别为26.27mg/g、6.15mg/g和0.98mg/g;经高钙废渣处理的污水,出水最清澈;高钙废渣对氨氮的吸附效果最好。用吸附效果最好的高钙废渣进行了模拟人工湿地吸附氨氮的基质柱实验,以高钙废渣为基质的模拟人工湿地对生活污水中氨氮的去除率为20%～42%。
Compared with conventional waste treatment systems,constructed wetland technology is simple operating and friendly maintaining.And it also has the superiority on cost and landscape value,etc.Substrate, such as slag or gravel,is one of the most important components in the building of constructed wetland system, and plays an important role in the removing process of some pollutants,such as phosphorus,in the constructed wetlands.But the removal of nitrogen by substrates is not high.Therefore,substrates have attracted great interest and have been extensively studied on their amount of adsorbing ammonium nitrogen.However,the capacity of the porous media such as high-calcium waste residue,modified red mud and vesuvianite adsorbing ammonium nitrogen has received little attention,especially high-calcium waste residue.High-calcium waste residue and red mud are by-products of refining aluminum,and belongs to solid waste.Vesuvianite is natural porous medium and modified red mud is the composition of 70%red mud and 30%high-calcium waste residue.In order to discuss the adsorption capacity of the three kinds of substrates and the application of the substrates selected,the isothermal adsorption experiment of substrates and the substrate column experiment were performed to study concentration variation and adsorption amount of the ammonium nitrogen.The research was organized in Guangxi University,located in Nanning,Guangxi Zhuang Autonomous Region.By isothermal adsorption experiment,fill the substrate selected from high-calcium waste residue,modified red mud and vesuvianite which has best adsorption capacity of ammonium nitrogen into the experimental column.First of all,isothermal adsorption experiment was carried out,and Langmuir equation,Freundlich equation and Henry equation were employed analyzing the data of adsorption amount of the three substrates,respectively.The result showed that Langmuir equation was the most suitable equation,and their correlation was 0.955（high-calcium waste residue）,0.937（modified red mud）,and 0.914（vesuvianite）with Langmuir equation,respectively; their correlation was 0.956,0.937,and 0.742 with Freundlich equation,respectively;their correlation was 0.947,0.798,and-0.032 3 with Henry equation,respectively.At the same time,it could draw the conclusion that the nitrogen adsorption capacity of high-calcium waste,modified red mud and vesuvianite was 26.27 g/kg, 6.15 g/kg,and 0.98 mg/kg with Langmuir equation fitting,respectively.Besides,the turbidity of effluent water treated by high-calcium waste was the lowest,and it was because modified red mud and vesuvianite had smaller specific surface area and looser Material than high-calcium waste residue.Therefore,the experimental column was filled with high-calcium waste residue.The high-calcium waste residue column experiment was carried out in order to investigate the removal capacity of ammonium nitrogen from domestic wastewater,and the removal rate of ammonium nitrogen was about 20%-42%in the column study for eight days.The experimental result showed that high-calcium waste residue had good adsorption capacity of ammonium nitrogen, meanwhile,pH maybe affect the removal rate of ammonium nitrogen.The research is not only providing scientific basis for choosing substrates of constructed wetlands,but also giving the method on treating solid waste like high-calcium waste residue.It is useful for comprehensive utilization of solid waste to fill constructed wetlands.
出处
《湿地科学》
CSCD
北大核心
2012年第1期87-91,共5页
Wetland Science
基金
广西科技攻关计划项目(桂科攻0663001-6)资助
关键词
氨氮
等温吸附
基质
人工湿地
ammonium nitrogen
isothermal adsorption
substrate
constructed wetland
