Aerobic Granular Sludge Cultivation And Its Performance Analysis Of Nitrogen And Phosphorus Removal

With the continuous improvement of the national environmental protection efforts,higher requirements have been placed on the treatment of urban domestic sewage.In order to improve the level of regional water pollution treatment and meet the discharge standards of municipal sewage treatment,intensive water treatment systems have become urban sewage Development direction of process technology in processing.The water treatment technology studied in this paper is the aerobic sludge particle treatment process.Under the artificial water distribution conditions,the difference between the granular sludge formed by the flocculent activated sludge under different cultivation methods and its nitrogen and phosphorus removal effects are studied..In addition,it also explored the successful cultivation method of aerobic sludge particles and the performance of nitrogen and phosphorus removal under the condition of domestic sewage as influent.According to the conditions of actual living influent pollutants,two culture processes are used for treatment,one is a separate SBR process,and the other is an anaerobic hydrolysis acidification coupled SBR process.The main technical results are as follows:(1)Establish three sets of sequential batch reactors(SBR).One group uses the traditional water intake method,that is,direct aeration after rapid water intake;one group uses the push-flow water intake method,and aerates after slow anaerobic water intake;one group uses anaerobic agitation method,rapid intake After agitating the water,aerate.In the three groups of reactors,the aerobic granular sludge cultivated by the anaerobic slow-flow inflow reactor has a smooth surface,its structure is the most compact,the sludge particle size is between 2.0-3.0mm,and the sludge concentration is9500 mg Around / L,it can remove more than 96% of TN,and the TP removal rate can reach 90%,and the long-term running state is relatively stable.(2)It is more difficult to culture activated sludge directly with domestic sewage.In the reactor,after 70 days of cultivation,the corresponding granular sludge has not been formed,and the TN removal rate is about 70%.In order to improve the efficiency of granular sludge treatment,methods such as reducing aeration time,increasing anaerobic water intake time,shortening reaction cycle time,and increasing cycle times are adopted.The experience of successfully cultivating aerobic granular sludge by adopting artificial water distribution with carbon source as the main source of sodium acetate.To verify the hydrolysis acidification step is to degrade macromolecular organic matter intovolatile organic acids such as acetic acid to promote the formation of granular sludge.After 70 days of cultivation,the particle size of the granular sludge appeared in the reactor was between 200-300 um.Although the flocculent sludge occupies the majority,the prototype of the granular sludge has basically formed.When the reactor runs to a stable period,the TN removal rate is about 70%,and the TN effluent concentration is below 15mg/L;the TP removal rate is 88%,and the TP concentration of the effluent is less than 0.5mg/L.(3)The scientific basis for the biological denitrification of aerobic granular sludge is based on the principles of nitrification and denitrification.Most of the aerobic granular sludge cultivated with artificial water with high organic load has a large particle size,and the process of oxygen transfer to the inside of the particles is limited,thereby forming a special structure inside the particles that is anoxic and aerobic on the surface.The mechanism of aerobic granular sludge denitrification is simultaneous nitrification and denitrification.(4)The actual domestic sewage is directly treated with mature aerobic granular sludge,COD effluent?25mg/L,TN effluent is about 5mg/L,TP effluent concentration is less than 0.5mg/L.After treatment,the water quality is good and the reactor operation remains stable.