Study On The Influence Of Ecological Factors On Key Enzymes Between PAO And GAO's Population Competition

Biological phosphorus removal is economic and feasible in many methods of phosphorus removal from wastewater.This method has also been widely used.It is depend on phosphorus accumulating aerobic phosphorus absorption features to remove phosphorus,but some scholars pointed out that biological phosphorus removal system will also produce GAO,two kinds of bacteria compete and absorb nutrients,so the phosphorus removal effect of the system is reduced greatly.It so far,a large number of studies of influencing factors between PAO and GAO are discussed,but few of them are discussing the enzymes.In this paper,the competition between the two involves the activity of key enzymes in the different ecological factors were discussed,and discussed different ecological factors on the system structure of the flora detection based on 16 S rDNA acer technology as to get more in-depth discussion of the competition.Depending on testing key enzymes,it have found between the relation ecological factors and the enzyme activity.When these six factors changed,the acid phosphatase activity and alkaline phosphatase activity are not effected.But PPX activity will be changed.These factors include: temperature,ph,carbon source and C/P,C/N,and DO.Appropriate increase in temperature can promote PAO growth,and PPX will increase.When adjusting alkalinity,PPX activity will change,and PPX is a neutral enzyme;When adjusting the carbon source,the molecular chain of carbon source is too long,which will cause the decrease of PPX activity;When C/P is adjusted,if the C/P is increased appropriately,the PPX activity will also increase.When the C/N ratio is adjusted,the PP/CX activity increases with the increase of C/N.There was no significant change in PPX activity when DO was adjusted.16S rDNA-based macro gene technology was used to detect sludge genetic characteristics,population structure,and sample similarity under different gradient ecological factors.The longer the domestication time of the sludge,the more uniform the type of colonies in the sludge,the more susceptible to the dominant population.At the level of samples,Proteobacteria accounted for the largest proportion;at the levelof class,Alphaproteobacteria accounted for the largest proportion;Changing the ecological factors will have a greater impact on the structure of the bacteria.When the temperature is adjusted,the diversity of the sludge community under low temperature conditions is lower than the high temperature.Under medium and low temperature conditions,PAO predominates,and under high temperature conditions,GAO predominates.When the alkalinity was adjusted,the diversity of sludge community under low alkalinity was lower than that of high alkalinity,moderate alkalinity and low alkalinity,PAO predominated,and GAO dominated under high alkalinity conditions.When adjusting the carbon source,when the carbon source with a long molecular chain is used,the sludge in the system is more diverse.In the system where these three different carbon sources are selected,PAO is always the dominant species,and acetic acid is the carbon source.The growth advantage of GAO is slightly obvious;When C/P was adjusted,the sludge community diversity under low C/P conditions was higher than that of high C/P,and PAO was always dominant in the three systems,but the GAO growth advantage in low C/P system was inferior to high C/P;When C/N was adjusted,the cluster diversity in sludge with low C/N ratio was lower than that with high C/N,and PAO was always the dominant bacteria group.GAO growth trend in high C/N conditions was better than that in low C/N conditions;When DO was adjusted,the diversity of sludge community under low-DO conditions was greater than that of high-DO,while in low-DO systems,PAO was the dominant bacteria.In high-DO systems,GAO was the dominant bacteria.