The Study Of Aerobic Granular Sludge Culture And Nitrogen Removal Performance Based On The Fe(0)-carbon-based Bio-carrier

Aerobic granular sludge has become a hot spot in recent years due to its advantages of spontaneous flocculation,good sedimentation,and strong biodegradability.However,the current culture of aerobic granular sludge has the problems of long culture period,complex influencing factors and poor operation stability,which limits its application in practice.Aiming at the above problems,this paper using sequencing batch reactor?SBR?to study a method for cultivating aerobic granular sludge based on iron matrix composites,and the cultivation of aerobic granular sludge denitrification and the factors affecting the actual sewage treatment effect were investigated,the main conclusions are as follows:?1?Experimental study on The cultivation of Aerobic Granular Sludge?The flocculant and facultative aerobic sludge was used as the seed sludge.The Fe?0?-carbon-based bio-carrier?FCBC?with particle sizes of 74-100 ?m and 100-150 ?m were added to the SBR reactor R1 and R2,respectively.After 70 days of cultivation,the aerobic granules with stable properties and compact structure were successfully cultured in reactor R1 with iron-based composites as carrier.?The main reason for the failure of granular sludge culture in reactor R2 is probably that the sludge growing on the surface of FCBC with larger particle size is easy to be destroyed,and the FCBC coagulated together and settle down to the bottom of the reactor,so they cannot function normally.?As the biodegradability of the reactor R1 and R2 was gradually increased,the average removal rates of COD,NH₄⁺-N,and TP from the aerobic granular sludge reached 90.88%,97.50%,and 76.8%,respectively,when the R1 culture was completed.The biodegradability and running stability are better than those of R2 flocculent sludge.?2?Experimental study on the influence factors of nitrogen removal from aerobic granular sludge?The experiment shows that the nitrification reaction and denitrification can be carried out synchronously during the process of denitrification of aerobic granular sludge.During the period?360min?,there is no accumulation of NOx-N??1mg/L?,and the efficiency of simultaneous nitrification and denitrification?SND?is 97.16%.?The effects of pH,aeration,and carbon/nitrogen ratio?C/N?on the denitrification of granular sludge were investigated.The results showed that the removal efficiency of NH₄⁺-N was 95.60%?97.87%when the C/N was 8,the aeration amount was 0.2m3/h,and the pH was 7.0.?3?Aerobic granular sludge treatment of domestic sewageThe campus sewage was used as the test water distribution.The treatment of aerobic granular sludge in actual domestic sewage was investigated.The results showed that the average removal rates of COD,NH₄⁺-N,and TP were 80.16%,91.18%,and 81.27%,respectively.Urban sewage treatment plant pollutant discharge standard?GB18918-2002?"Class A standard.The granular sludge has the advantages of short reaction cycle,stable treatment effect,high space utilization,and low sludge discharge.It can maintain a good nitrogen and phosphorus removal capacity without adding additional carbon sources.The separation effect is good and it has the value of engineering application.