Study On Low Ammonia Wastewater Treatmen With Shortcut Nitrification-anammox Process

Shortcut nitrification-ANAMMOX process is based on the reaction mechanism of shortcut nitrification and ANAMMOX,which combines the two processes together.The denitrification process has so mang advantages like no external carbon source,low cost,energy-saving and environmental protection,etc.,that it is welcomed by people.The study aimed at the treatment of low-ammonia wastewater is divided into three parts.The first part is the study of shortcut nitrification reactor startup and influencing factors.The second part is the study of the effect of elastic packing on nitrite bacteria enrichment.The third part is the study of ANAMMOX reactor startup and the jointing of the two processes.In the first part,SBR reactor was used and inoculated the nitrifying sludge with high active.The shortcut nitrification was successfully achieved after nearly a month of domestication cultivation.In addition,factors(such as temperature,pH,dissolved oxygen concentration)of short nitrification process was further studied.The results showed that:In startup phase of shortcut nitrification,intermittent aeration mode should be adopted,and DO concentration was maintain within 1.0mg/L by adjusting the amount of aeration.Shortcut nitrification could be quickly achieved in the conditions of 30±1?,pH 7.8-8.2,intermittent aeration.When temperature at 25?35? and pH at 7.8?8.2,it was suitable for shortcut nitrification reacting and the effect of effluent became better with rise of pH and temperature.When nitrite bacteria was dominant bacteria,NO2--N concentration in effluent increased with DO rising at DO 0?1.5mg/L.In the second part,three same reactors was used to enrich nitrite bacteria.The first reactor was not added with adding filler;The second reactor was adding with elastic filler;The third reactor was not adding with filler until the nitrification rate was over 70%.The results showed that:Filler could provide more attachment points for the growth of microorganisms,so it made the sludge existing as the form of suspension and fixation in reactor.The unique structure of elastic filler made biomass enriched,and increased the contact area of microorganisms with a sewage.Therefore,organics were more easily degraded by microorganisms,and COD was efficiently removed in a short time.When nitrite bacteria had become dominant bacteria,filler should be added and DO should increased appropriately to enrich nitrite bacteria.In the third part,ANAMMOX biofilter was used as anammox reactor,and ANAMMOX was successfully achieved after running 120d.Then shortcut nitrification was combined with ANAMMOX.The results showed that:It could shorten the startup time while culturing autotrophic denitrification biofilm before startup ANAMMOX.In the stage of jointing processes,the effluent of shortcut nitrification process that NO2--N/NH4+-N was in 1.15?1.35 should be selected as the influent of ANAMMOX process.Since substrate concentration of effluent was in a low level from shortcut nitrification process,it took less time to joint the processes by raising the filtration rate to increase the substrate concentration.