Study On The Performance And Safety Assessment Of Chinese Medicine Residue As An Additional Carbon Source In The Denitrification Process Of Sewage Treatment Plant

Currently,most wastewater treatment plants have insufficient carbon sources,and additional carbon sources need to be added to achieve the purpose of nitrogen removal from wastewater.Currently,the commonly used additional carbon sources include sodium acetate,methanol,and glucose.However,these carbon sources have a high cost,and there is a risk of worsening the tail water.Therefore,seeking efficient,economic,and stable carbon sources has become an important issue faced by wastewater treatment plants.In this paper,the traditional Chinese medicine residue from a factory in Tianjin was used as an additional carbon source in the SBR reactor,and the denitrification performance was studied using sodium acetate as a control experiment;The denitrification and denitrification performance of traditional Chinese medicine residue as an additional carbon source used in wastewater treatment plants was studied and its process safety evaluation was conducted,providing a new way for the resource utilization of traditional Chinese medicine residue.The experimental conclusions are as follows:The main components of traditional Chinese medicine residue are sugars,fats,and proteins,with the content of 36.54%,12.77%,and 3.55%,respectively;When traditional Chinese medicine residue and sodium acetate are used as external carbon sources in the SBR reactor,the removal rates of COD and NH₃-N in wastewater can both reach over 90%.However,when traditional Chinese medicine residue is used as carbon source,the removal efficiency of TN and TP is inferior to that of sodium acetate.However,with the operation of the reactor,the TN removal rate can reach over 80%,and the TP removal rate can also reach a maximum of over 90%;It can have a positive promoting effect on sludge particle size,sludge settling ratio,and sludge concentration;The microbial community structure showed that the two reactors had the same microbial species at the phylum level,but different abundances.When the Chinese medicine residue was the carbon source,the microorganisms in the reactor were mostly classified into Proteobacteria at the genus level,which could achieve the purpose of denitrification and denitrification as a carbon source;In the actual application of traditional Chinese medicine residue as a carbon source to treat wastewater from a wastewater treatment plant,it was found that the removal rates of COD and NH₃-N were 86%and 75.11%,and the removal rates of TN and TP were63%and 80%or more,and most of the nitrate nitrogen could be removed to achieve the purpose of denitrification and denitrification;The main risks in the two systems of traditional Chinese medicine residue as an external carbon source process,namely the pretreatment system of traditional Chinese medicine residue and the application system of traditional Chinese medicine residue,are poisoning and suffocation,electric leakage shock,drowning,fire explosion,and mechanical injury.Among them,the four types of risk hazards,electric leakage shock,drowning,fire explosion,and mechanical injury,are relatively high and require high attention.