Microbiology Research On N And P Removal In Mixed Wastewater Of Constructed Wetlands

This topic was based on the overall requirements of the National "Twelfth Five-Year" Plan for water pollution control and the development of regional ecological environment in the Haihe River Basin.In view of the middle reaches of the Haihe River water system showing that the complex pollution characteristics,and a new type of constructed wetland which had aeration devices was designed.This thesis was divided into three stages of the experiment to explore the contribution rates of combined constructed wetland under different conditions.The removal of N and P in the mixed wastewater was studied by using molecular biology technology and bioinformatics technology.The main conclusions of this article are as follows:(1)Through orthogonal test,the optimum operating conditions of the combined constructed wetland were determined.Hydraulic retention time was 4d,BOD5/CODCr was 0.2,the aeration position was surface aeration,and aeration rate was 9m L/min.We set up three devices of intermittent aeration in winter,which intermittent aeration time were 8h?10h and 12 h.Through pollutants of TP,TN,ammonia nitrogen,nitrate nitrogen,SS and CODCr removal,the best intermittent aeration time of 8h was determined.(2)Three sets of devices about large aperture aeration were set up: the surface aeration,30 cm distance from the bottom and 20 cm from the bottom.Through the determination of the conventional index,the optimal water effect of the device with 30 cm distance from the bottom was determined.A total of 20 samples were carried out by microbiology,we found 11 kinds of microorganisms associated with the removal of nitrogen: Limnohabitans,Pseudomonas,Aquicella,Rhodobacter and Cyanobacteria,et al.6 kinds of microorganisms associated with the removal of phosphorus were determined: Acidobacteria,Xanthomonadales,Betaproteobacteria,Chloroplast,Acidovorax and Proteobacteria.(3)As a contrast,three sets of devices about microporous aeration were used in this experiment: the surface of the micro aeration,30 cm distance from the bottom,20 cm distance from the bottom.By the conventional index,the optimal water effect of the device with 20 cm distance from the bottom of the micro aeration was determined.A total of 20 samples were carried out by microbial diversity analysis,14 kinds of microorganisms associated with the removal of nitrogen were determined: Limnohabitans,Fluviicola,Pseudomonas,Methylophilacterium,Aquicella,Rhodobacter,Azospirillum,Achromobacter and Aeromicrobium,et al.8 kinds of microorganisms associated with the removal of phosphorus were determined: Brevundimonas,Chlorobaculum,Pseudorhodoferax,Methylophilacterium,Bacillus,Panacagrimonas,Leptospira and Variovorax.