Exploratory Research Of Anaerobic Hydrolysis-nitrosation Anaemmox Process Treating Rich Ammonia Fertilizer Wastewater

The NH₄⁺-N concentration of fertilizer wastewater is rich.If it can not be handled and controlled effectively,it will cause serious pollution and damage to the environment and resources.The C/N ratio of fertilizer wastewater is low,which makes the biodegradability bad.Traditional nitrification and denitrification technology requires additional carbon,which needs high economic costs.In this study,the text water is fertilizer wastewater.Based on the feature of fertilizer wastewater,the treatment applied combined anaerobic hydrolysis,nitrosation and anammox process.And the effect was inpected.Around anammox reaction,the research was carried out.In order to meet the requirement of anammox reaction on NH₄⁺-N and NO2--N,the start-up experiment of nitrosation was conducted firstly,which determined the difficulty and feasibility of it.When influent pH was at 8,temperature was at 25?,HRT was at Id,upflow velocity was at 1m/h,nitrification reactor was successfully started up.When influent NH₄⁺-N concentration was 100mg/L finally,the removal rate is 60%.55%of the total NH₄⁺-N was converted into NO2--N.It met the need of anammox to NH₄⁺-N and N02--N.Secondly,the study inspected the effect of combination process treating fertilizer wastewater.In order to realize the operation of anaerobic ammonia oxidation as soon as possible,at the same time reduce the difficulty of field experiment,the way of dosing nitrite was adopted.The results showed that COD?NH₄⁺-N and TN removal efficiency reached 70%,60%and 60%respectively.The main function of anaerobic hydrolysis was removal of COD.The main function of annamox was removal of NH₄⁺-N and TN.By opening the system of water reflux,it made anaerobic hydrolysis have the function of denitrification,which increased the advantage of combination process.The effluent TN and NH₄⁺-N concentration reached 50mg/L and 25mg/L.The results showed that the combination process was feasible.In the end,analyzing microbial colony of anammox activated sludge by Miseq sequencing technology,the results showed that:the highest proportion of bacteria is proteobacteria.At species level,it showed that there was Nitrosomonas europaea,which has ammonia ability.Nitrosomonas europaea belongs to Nitrosomonas?Nitrosomonadales?Betaproteobacteria?Proteobacteria.It can use NO2--N as electron acceptor,and oxidize NH₄⁺-N to N2.With no oxygen,the anammox reaction rate was received by detecting the consumption of NH₄⁺-N and NO2'-N.With no COD,the rate was 4.14mgNH₄⁺-N/?gVSS·h?or 5.97mgNO2--N/?gVSS·h?.With the presence of COD,the rate was 3.5mgNH₄⁺-N/?gVSS·h?or 6.5mgNO2'-N/?gVSS·h?.The existence of COD affected the competition of anammox bacteria,which inhibited the activity of anammox reaction.In the combination process,using anaerobic hydrolysis process as pretreatment can greatly decreased COD concentration that inflow into anammox reactor,which provides a powerful guarantee for nitrosation anammox treating fertilizer wastewater.