Study On Optimization Of Exterior Microorganism To Biofilm Biodegradation Micro-ecosystem

Biodegradation efficiency could be improved by bioaugmentation,that was to construct and cultivate micro-ecosystem in the reactor.This method had important practical sense to the application of enteric microorganisms in the wastewater treatment.But the entic microorganisms degenerated because of the change of environment and so the biodegradation efficiency rebounded,the time of stabilization operation of the system was very short.Casted new entic microorganisms was needed.Based on the theory of bio-selection, the possibility of forming EM co-culture biofilm were studyed by adding extraneous microorganisms-EM at the prime of the forming of conditional biofilm.The differences of the process of biofilm foming,biofilm quantity, microbial activity,biofilm micro-ecosystem's comprise and structure between conditional biofilm and co-culture biofilm were studyed.The method of optimizing micro-ecosystem was looked forward to,constructing stabilize micro-ecosystem.The main conclusions were summarized as follows:(1) The exterior microorganism could adjust mutual effects between species and community of microorganisms in the biological degradation micro-ecosystem on one hand, and increase the microorganism concentration and its metabolism activity on the other hand. From which the target of optimizing micro-ecosystem is reached.(2) The mode of co-culture was helpful to the forming and maturation of the biofilm,could shrten the period of biofilm forming. Accomplishment Removal efficiency of COD,NH3-N,TN,TP were 5．37%,25．40%,38．10%,9．14% higher than conditional system.(3) Co-culture system had better performance than conditional system until three months's operation.Two syytems's operational effect was about the same after three months's and even co-culture system had worse performanc than conditional system.The reason of this was that co-culture system's micro-ecosystem was assimilated by indigenous microbial in the wastewater.(4) The mode of co-culture was helpful to the biofilm quantity and microbial activity.The results showed that co-culture system's biofilm lipid-P quantity was 2．44 and 2．52 times as much as conditional system at the highet of 5cm and 15cm of sample,but the difference at their own system was very small.Co-culture system's microbial activity was 1．17 and 1．18 times as much as conditional system at the highet of 5cm and 15cm of sample.The biofilm quantity and microbial activity of the biofloccule between the carrier were higher than biofilm.(5) Micro-ecosystem's comprise and structure of conditional system and co-culture system had similitude and difference.The results of PLFA(phospholipid fatty acids) showed that 17 kinds of fatty acid methyl ester in each system was monitored,the kinds were almost same, but the ratios of each fatty acid in each system were different.The ratios of trans-and cis-fatty acid in conditional and co-culture systems were 6．04 and 8．82,this datas showed that microorganism in two systems were bad.The reason of this was that the biofloccule between carriers affected microorganism of biofilm to get nutrient and oxgen.