Technology And Application Of Water Ecological Restoration In Cold And Arid Areas Based On Biological Floating Islands

The water ecological environment is closely related to human life.Due to the rapid development of technology and industry,the water ecological environment in China has been threatened to a certain extent,and water ecological restoration has become a theme in today’s society.Biological floating island is an in-situ water ecological restoration technology.Domestic research on biological floating island mainly focuses on the Taihu lake,Dianchi lake,the Yangtze River Delta and the Three Gorges reservoir area,and rarely takes the water body in the northern cold and dry areas as an example.Wuliangsuhai is a large grassland lake in the northern cold and arid region.This article studies the combination of cold tolerant plants and mixed plants suitable for eutrop Hication restoration of lake water in the northern cold and arid region through static simulation of Wuliangsuhai water body,providing reference for biological floating island plant selection and cultivation techniques for water restoration in the northern cold and arid region.The main research content and conclusions are as follows:By collecting lake water samples and surface sediment samples at the site of Wuliangsuhai and conducting experimental analysis,the water quality characteristics of Wuliangsuhai were obtained,and pollution assessments were conducted on the water and sediment,respectively.Experimental analysis shows that:（1）The overall average comprehensive nutritional status index of Wuliangsuhai is moderately eutrop Hic.In the entire area of Wuliangsuhai Lake,5.55%is a severely eutrop Hic area,72.22%is a moderately eutrop Hic area,and 22.22%is a lightly eutrop Hic area.Overall,the spatial distribution characteristics of the comprehensive nutritional status index value of Wuliangsuhai Lake in the lake are high in the south and low in the north.（2）The pollution status of surface sediment in Wuliangsuhai is as follows:clean ratio is 0,mild pollution ratio is 5.55%,moderate pollution ratio is 5.55%,and severe pollution ratio is 77.78%.Six plants,including canna,iris,water celery,mint,celery,and sunflower,were selected for a single plant static simulation experiment and analysis.The experimental analysis showed that:（1）in terms of TN removal ability,iris>Lythrum Salicaria>water celery>canna>mint>sunflower;（2）In terms of the ability to remove TP,Lythrum Salicaria>Iris>Canna>Sunflower>Water celery>Mint;（3）In terms of the ability to remove TP,iris>Lythrum Salicaria>canna>sunflower>Water celery>mint.Static simulation experiments and analysis were conducted on mixed plants of Canna,Iris,and Lythrum Salicaria.The experimental analysis showed that:（1）in terms of TN removal ability,Lythrum Salicaria+Canna+Iris>Lythrum Salicaria+Iris>Lythrum Salicaria+Canna>Canna+Iris;（2）In terms of the ability to remove TP,the ratio of Lythrum Salicaria+Canna+Iris>Canna+Iris>Lythrum Salicaria+Iris>Lythrum Salicaria+Canna;（3）In terms of the removal ability of COD_Mn,Lythrum Salicaria+Canna+Iris>Lythrum Salicaria+Iris>Canna+Iris>Lythrum Salicaria+Canna.Based on the above,canna,celandine and iris are hardy plants and mixed plant combinations suitable for eutrophication restoration of lakes in the cold and arid regions of the north.