Research progress of application of slow-release carbon sources in nitrogen removal of sewage with low carbon-nitrogen ratio
When treating sewage with low carbon-nitrogen ratio,insufficient carbon source during the process of biolobical nitrogen removal and denitrification is easy to lead to low nitrogen removal efficiency,which needs to be compensated by adding additional carbon sources.As external carbon source is widely used in sewage nitrogen removal process,its defect that the dosage is not easily controlled can be remedied by adopting slow release technology.The characteristics of carbon source slow-release and its application status in treatment of sewage with low carbon-nitrogen ratio were elaborated,different types of solid slow-release carbon sources as well as their enhanced effect on biological denitrification and nitrogen removal were summarized,besides,the advantages and disadvantages of different slow-release carbon sources in nitrogen removal were compared and analyzed.The limitations of the current application of slow-release carbon sources were pointed out,and the development direction of slow-release carbon source in fields of biological denitrification and nitrogen removal was prospected.