Anammox Treatment Of High Salt Wastewater And Practical Application Of Denitration Tail Liquid In Power Plants

Salt and ammonia nitrogen are the characteristics of many industrial waste water.With the increasing discharge of such waste water,the pollution of water body is gradually aggravating.Anaerobic ammonia oxidation technology has the advantages of low cost,small footprint,no need for oxygen exposure,and no need for organic carbon sources compared to traditional biochemical nitrogen removal.It is a resource-saving and environment-friendly biological nitrogen removal method.The treatment of salt industrial wastewater has enormous potential advantages.This article uses the anammox process to study the removal of nitrogen from salty wastewater and desulphurization wastewater from thermal power plants.The following results are obtained:The secondary start-up of the ASBR anammox reactor after three months of stopping operation was studied.The results showed that the secondary start-up of the mid-tested Anammox-ASBR system can be achieved rapidly with low initial substrate concentrations(initial NH4+-N and NO2--N concentrations of 90 and 120 mg/L,respectively).Among them,a large amount of granular sludge is conducive to the rapid recovery of anammox activity.After two weeks of recovery,the removal rates of ammonia nitrogen and nitrite nitrogen gradually recovered to more than 95%,and the sludge color gradually changed from black with odor to brick red.The denitrification characteristics of high salinity wastewater treated by anammox bacteria were studied under different Cl-concentrations.The results showed that anaerobic ammonium oxidizing bacteria can maintain high nitrogen removal performance in each gradient below 12000 mg/L Cl-.Among them,in the two gradients of Cl-concentrations of 6000 mg/L and 10000 mg/L,the denitrification performance of the reactor was inhibited by the larger salinity,but as the acclimation process continued for a long time,the denitrification performance of the reactor gradually recovered.The modified Boltzmann model was able to fit the recovery process more accurately when the reactor was restored to activity after inhibition by different salinities.The correlation coefficient R2 was above 0.96.After the acclimation of salinity,the dominant anaerobic ammonia-oxidizing strain was Candidatus Brocadia.The degree of granulation and the density of sludge increased to varying degrees.The sludge color was reddish-brown.The denitrification efficiency of the actual desulfurization wastewater and the influence of other factors in the wastewater on the anammox bacteria were studied.The results showed that after the high-salinity(Cl-12000 mg/L)acclimated pilot-scale Anammox-ABSR,the addition of different proportions of actual desulfurization wastewater from thermal power plants had less effect on the denitrification characteristics.Under the conditions of different desulfurization wastewater addition rates,anammox bacteria can gradually adapt to and maintain high nitrogen removal activity.The NREmax of the modified Logistic model is close to the actual experimental value,which is more suitable for describing the denitrification process under high salinity desulfurization wastewater conditions.R2=0.99384,NREmax=97.68994,Rmax=8.3314.The effect of COD on ANAMMOX bacteria in desulfurization wastewater was studied.The COD that can be bio-utilized in the desulfurization wastewater is less,and the COD concentration is generally low,which does not cause the inhibition of anammox activity.Under the condition of low COD concentration,increasing the C/N ratio can promote the denitrification process,which is reflected in the decrease of nitrate concentration in the effluent and the increase in the removal rate of total nitrogen.