Study On The Application Of Additional Carbon Source For The Removal Of Nitrogen And Phosphorus

In order to solve the problem of low efficiency of biological nitrogen and phosphorus removal,the addition of carbon sources has become one of the measures taken by most sewage treatment plants.There are many types of carbon sources,and different types of carbon sources have different nitrogen and phosphorus removal effects and costs.In this study,the simulated wastewater and actual domestic wastewater were used as treatment objects,and through batch test and SBR process to explore the nitrogen and phosphorus removal effect of different external carbon sources.And select a suitable carbon source based on the cost of the carbon source.The main results of this paper are as follows:By investigating the effects of different single and mixed carbon sources on the denitrification and anaerobic phosphorus release of simulated wastewater,the results show that:according to denitrification,anaerobic phosphorus release effect and carbon source cost,it can be known that sodium acetate+glucose is more suitable as an additional carbon source for nitrogen and phosphorus removal from wastewater.And by 180min,the removal rate of NO₃^--N and TN in wastewater by sodium acetate+glucose system were 100%and77.91%,respectively.By 140 min,the amount of TP released by sodium acetate+glucose system was 39.54 mg/L.Using sodium acetate:glucose as 3:1,2:1,1:1,1:2,1:3(calculated as COD_Cr)as additional carbon sources,and explore its denitrification and anaerobic phosphorus release effects on simulated wastewater,the result shows:according to the denitrification,anaerobic phosphorus release effect and carbon source cost,it can be known that sodium acetate:glucose as 1:1 is more suitable as an additional carbon source for nitrogen and phosphorus removal from wastewater.Using SBR process and adding different carbon sources to domestic sewage,the results under operating conditions indicate:at the appropriate temperature?27.6²8.9??and around 12?,for dosing carbon source systems,its nitrogen and phosphorus removal effects have increased,but different carbon source systems have different increases.Among them,sodium acetate+glucose is more suitable as an additional carbon source for domestic nitrogen and phosphorus removal.Under the appropriate temperature conditions,the removal rates of TN,TP,and COD_Crr by the sodium acetate+glucose system ranged from66.6%to 77.1%,85.3%to 92.0%,and 81.2%to 85.7%,respectively.At around 12?,the removal rates of TN,TP,and COD_Crr by the sodium acetate+glucose system ranged from52.8%to 59.2%,86.6%to 90.8%,and 75.4%to 80.9%,respectively.Compared with the suitable temperature,the denitrification effect of sodium acetate+glucose system is poor at about 12?,but the temperature change has no significant effect on the phosphorus removal effect.Sodium acetate+glucose as an external carbon source,and at suitable temperature?27.6²9.9??and about 12?,with the increase of MLSS,the nitrogen removal effect of SBR system on domestic sewage increased in turn.Increasing MLSS in a certain range can increase the removal effect of TP by the system,but too high MLSS will reduce the removal effect of TP by the system.When the carbon-nitrogen ratio is about 7,it is more appropriate to control MLSS at 4000⁴600mg/L.The preferred carbon source in this paper can provide a reference for the enhanced nitrogen and phosphorus removal effect of urban sewage treatment plants.