Research On The Key Technology Of Constructing Natural Functional Wetland In Low Temperature Area

Natural water is the most common form of water resources in nature.The constructed wetland has good consistency with natural water in construction and operation,and is suitable for the treatment of natural water.However,the natural conditions of river basins are not consistent with the water quality,and the problem of low temperature period is most prominent in the north.It is urgent to establish a constructed wetland water treatment and purification system which can operate stably in low temperature period.Under the condition of maintaining the natural state,the operation condition of No.8Bridge wetland in the low temperature period was investigated under the condition of higher pollutant concentration and less water flow compared with the normal temperature period in the yongding River low temperature period.The diversity of plankton in and out of the water changed significantly.The zooplankton Shannon-Wiener index increased from 0.12 to 0.48,the Margalef index decreased from 29.14 to 8.03,and the Pielou index increased from 0.04 to 0.1.The phytoplankton Shannon-Wiener index increased from 2.03 to 2.51,the Margalef index decreased from 2.80 to 2.59,and the Pielou index increased from 0.36 to 0.46.After the addition of microbial agents,the number of OUTS in each wetland increased significantly,flavobacteria in ichthyosis wetlands such as vermina in underflow wetlands,etc.,and the relative abundance of functional bacteria such as sphingomonas sphingomonas in surface flow wetlands increased significantly.The average removal rates of COD,TP,TN,NH₄⁺-N,NO₃^--N,and NO₂^--N in the first treatment area at low temperature were 33.4%,46.5%,50.6%,47.6%,37.9%and66.5%respectively.The average removal were 50.5%,59.8%,48.5%,18.7%,75.7%and48.5%respectively in the low-temperature subsurface flow wetland area.The average removal were 23.39%,62%,67.6%,71.25%,68.37%and 61.2%respectively.Figure 52;Table 21;Reference 85...