Characteristic Analysis Of In-situ Remediation Of Pollutants And Microbial Community In An Integrated Ecological Pontoon

With the rapid development of social economy,urban residents have higher and higher requirements on the living environment.As an important part of the livable environment,landscape water bodies are increasingly appearing in urban green spaces,ecological parks and residential areas.Due to the small water environment capacity and poor water mobility,most landscape water bodies have limited self-purification ability and are susceptible to pollution,leading to deterioration of water quality and even black odor.On this basis,this study designed and produced an integrated ecological pontoon suitable for in-situ restoration of landscape water bodies.Build an on-site test platform,and perform in-situ repair on landscape water bodies with an integrated ecological boat;using 16 Sr RNAV3-V4 as the target gene,the microbial community structure of each processing unit integrating the ecological pontoon was analyzed by high-throughput sequencing.The following main conclusions are drawn:①The design of the integrated ecological floating boat device integrates in-situ repair technology and multiple biofilm processes to achieve the integrated integration of modules such as grids,biological filters,ecological turntables,and ecological floating beds.The structure of the device is more compact,and there are no extra pipes between the process units,which reduces the cost.The integrated ecological pontoon has a total length of 3.49 m and a width of 1.2m.The volume of the biological filter system is 0.35m3,the ecological turntable system is a single-axis three-stage type,each stage has 11 turntables,and the turntable area is 31㎡.The ecological floating bed system uses 6 groups,the plants adopt Thalia dealbata Fraser,and the fiber fillers are used to bind the plant roots.②In the experiment of repairing the artificial lake water body by the integrated ecological floating boat,the method of combining the natural hanging film with the artificially added strain hanging film was used to carry out the film hanging test.On the 14 th day of operation in the natural environment,the COD and the concentration of ammonia nitrogen tends to be stable,and the removal rate reaches 70% and 65% respectively,and a thick brown biofilm appears on the surface of the filler in the device.This indicates that the device has successfully hung the film.During the stable operation of the integrated ecological pontoon under the design conditions,the average removal rates of the device for the COD,ammonia nitrogen,total nitrogen and total phosphorus in the artificial lake are 77.72%,69.58%,58.91% and 56.17% respectively.The concentration of COD,ammonia nitrogen,total nitrogen,and total phosphorus can meet the "Water Quality of Landscape Environmental Water for Urban Wastewater Recycling(GB / T18921-2002)".During the test,the water quality of the inlet water of the device fluctuated greatly,but the water quality of the effluent was still relatively stable,indicating that the device has a certain resistance to water quality impact.③The microbial community structure of each processing unit of the integrated device has obvious seasonality.High-throughput sequencing of 12 samples yielded 28 microbial phylum and 49 microbial genus.At the phylum level,Proteobacteria,Bacteroidetes,Actinobacteria and Chloroflexi are the dominant phylum of the device.At the genus level Hyphomicrobium,Porphyrobacter,Aeromonas,Porphyrobacter and Gemmobacter are the dominant genus of devices in September;Hyphomicrobium,Hydrogenophaga,Massilia,Porphyrobacter and Gemmobacter Is the dominant genus of bacteria in the device in December.Among them,total nitrogen,nitrite nitrogen and p H in the environment are significantly different from the OTU value,and nitrate nitrogen and total phosphorus are particularly significantly different from the OTU value.④The daily processing scale of the integrated ecological floating ship is 70m3/d,the one-time input cost of the equipment is24750 yuan,and the annual operating cost is only1755.25 yuan.Compared with the traditional integrated sewage treatment equipment,the integrated ecological floating boat does not occupy land,has less investment,has a compact structure,is easy to operate,has low operation and maintenance costs,can also be unattended,and is suitable for the purification of urban landscape water.