Advanced Nitrogen Removal Of Denitrification Filter With Corncob As Slow-release Carbon Source

Urban effluent secondary treatment TN does not meet the level of A standard,which makes it necessary to be advanced.However the insufficient water source makes it difficult to denitrification,so the additional carbon source is needed.Solid carbon sources can act as carbon carriers while acting as carbon sources,thus they are often used as additional carbon sources.Among many solid slow-release carbon sources,corncob is more suitable as a slow-release carbon source in term of denitrification and cost.Additionally,corncob in China are mostly burned traditionally.It is better if we can use it as a carbon resource.However,since the components of the corncob that are not easily utilized,the corncob needs to be treated specilly.In this paper,the denitrification efficiency of corncob and alkali treatment corncob as the slow release carbon source with white rot fungi.was investigated by using denitrifying filter as the main reactor.In this paper,a denitrifying filter?alkali reactor?with alkali-treated corncob was used as a carbon source,a denitrification filter?corncob + bacteria reactor?with corncob and white rot fungi and alkali treated corncob as carbon source and white rot fungi of the denitrification filter?alkali + bacteria reactor?,I analyzed its best HRT,operating efficiency and effective operating cycle.By comparison,the effect of corncob + bacteria reactor is the best.The removal rate of TN and NO₃^--N was 92% and 98%,respectively,under the condition of HRT = 70 min,when I set the TN as criterion.In order to verify the accuracy of the results,the microbial community structure of three groups of denitrifying filters was analyzed by high throughput sequencing technique.In terms of fungal level,the microbial diversity of the alkali reactor was the largest.In terms of bacterial level,the microbial diversity of the alkali + bacteria reactor was the largest.White rot fungi were found in the corncob + bacteria reactor and the alkali + bacteria reactor,and the content of white rot fungi in the alkali + bacteria reactor reached 18.30%.Bacterial with denitrification was found in the three denitrification filters.The denitrifying bacteria have the highest abundance of 13.32%,which is also the best for denitrification.So corncob as a carbon source with white rot fungi reactor is for follow-up corncob replacement experiment.Because the corncob had lost effect,we replaced the damaged corncob with a replacement ratio of 1/2,1/3,1/4 and 1/5.With the criterion of TN,it was found that the replacement of 1/4 corncob could run for 31 days.And the removal rate of NO₃^--N can be more than 70%.The application of environmental scanning electron microscopy revealed that the biofilm was the thickest on the surface of corncob when replacement ratio is 1/4.When HRT is 70 min,according to the removal rate of COD?TN and NO₃^--N,corncob as carbon source with plus white rot fungi reactor of the optimal packing replacement ratio is 1/4.