Exogenous Protective Agent’s Effect On The Aerobic Biochemica Treatmentof Thesalt Wastewater At The Low Temperature

Biological treatment often has to face the challenge because of the wastewater containins a certain concentration of salt that can cause toxic effects to microorganisms and inhibit their activity,which resulting in reduced wastewater treatment efficiency in wastewater.After a brief summary of the high-salt organic wasterwater treatment by addition of compatible solutes at home and abroad in this paper in recent years,the influential impact and the law of action of the five kinds of exogenous protections of betaine,KCl,trehalose,sucrose and choline on the low temperature nitrification of high salt wastewater which artificial simulating was studied in view of the low efficiency of the high salt wastewater treatment under the low temperature(<10℃).Then,to study the goal that the recovery of abnormal sludge found in the biochemical treatment of mustard wastewater by siting investigation,the effects of low temperature and low temperature and salinity coupling were studied to know about its low temperature regulation effect by adding the exogenous protective agent,and selected the 1-2 kinds of exogenous protective agent which improving the effect of nitrogen and phosphorus removal,and to provide guidance for the application of exogenous protective agents.In this paper,the microbial flora diversity of the sludge was also analyzed by high-throughput sequencing technique to explore the mechanism of the effect of the exogenous protective agent on the activated sludge system.The results are as follows:(1)It was found that the abrupt change of the Na~+0～10g/L and 10～20g/L salinity both had a significant negative effect on the removal rate of ammonia nitrogen and phosphate in high salt wastewater aerobic biological treatment test of the artificial simulation.The addition of an exogenous protective agent in the reactor will be alleviated to some extent,with the exception of the choline group.(2)It could be inferred that the effect of betaine,trehalose and sucrose on the low temperature nitrification of artificial simulated wastewater was better.In the case of ythe denitrification,the addition of betaine and sucrose was best under the impact of Na~+10g/L and 20g/L salinity,which increased by 8.2%and 7.4%,respectively,compared with the control.For phosphate removal,the trehalose palyed the best with an average increase of 3.2%and 5.6%under the different salinities.(3)After a period of acclimated aerobic activated sludge to deal with the impact of salinity in the nitrogen and phosphorus removal is significantly better than the non-domesticated sludge,even if the impact of higher salinity,the system of ammonia nitrogen,phosphate removal rate was significantly higher than which of the lower salinity impact of the unregulated sludge.(4)It was found that the sudden impact of salinity will affect the nitrification and denitrification process in a short time,and the microbial will be adjusted in time to deal with salt stress in order to response to the salinity of the system.From the trend of NH3-N and PO43-removal rate,phosphorus microbes are more sensitive to salinity than denitrifying microorganisms.(5)The low temperature had a negative effect on the removal rate of ammonia nitrogen,phosphate and CODcr,the effect of the betaine on ammonia nitrogen removal was better than that of blank group,which was 2.6%higher than which of the blank group.The negative effect of low temperature-salinity coupling on the biochemical treatment system of mustard wastewater was more obvious,under low temperature and salinity coupling,betaine has a certain advantage in the removal of the ammonia nitrogen and CODcr,which is 4.4%and 4.9%higher than that of blank group,and the average increase of trehalose in phosphate removal is 3.4%.(6)The results showed that there were no significant differences in the composition of the samples and similar to the door and sort in the 16SrRNA sequencing by analysizing the microbial flora diversity of the four samples in the actual mustard wastewater biochemical treatment process,but there were some differences in the content of the microbial flora in the second stage.The results showed that the species and the abundance of bacteria in the 2.1#reactor with betaine was higher than any other system.In the ITS sequencing,the richness and diversity of the fungi were superior to those of the other systems.The superiority and the high content of Mucoria showed that the degree of deterioration which the microbial environment within the system was more obvious.(7)There were nsignificant differences in the diversity of biological bacteria during the system affected by low temperature and which of affected by the low temperature and the salinity simultaneously according to the results of PcoA analysis,but the difference degree during the systems which ingdd different kinds of exogenous protective agent was similar.The mutation of salinity and the addition of exogenous protective agents both had a significant effect on the species diversity of the fungi in the system.The system which adding the betaine was significantly less affected by low temperature and salinity impact than other systems.