Study On Enhanced Hydrolysis,acidogenesis And Denitrification Of Food Waste Liquor

With the increasingly strict standard of nitrogen and phosphorus in the effluent of municipal wastewater treatment plants,the denitrification process is difficult to c arry out effectively due to the low carbon nitrogen ratio in the operation of municipal wastewater treatment plants,so the demand for additional carbon sources is vigorous.The food waste liquor contains a lot of organic matter,and the demand for its own treatment and disposal is increasing year by year.Therefore,the recovery of dissolved carbon source products from kitchen waste wastewater as denitrification additional carbon source can not only achieve resource recycling,but also achieve joint treatment.In this research,the medium temperature anaerobic acidogenic fermentation of food waste liquor from a food waste treatment site was carried out.The effect of pH on anaerobic acidogenic fermentation of food waste was studied.The fermentation broth with volatile fatty acid(VFA)content of 36.92g/l was obtained when pH=6 and fermentation time was 6 days.Based on the analysis of the organic matter changes in the fermentation of food waste liquor,the results showed that the fermentation process of food waste wastewater experienced two processes:lactic acid production and propionic acid production&butyric acid production.The results showed that the fermentation broth with high C/N ratio could be obtained in both shaking table reactor and quadruple anaerobic reactor,and the propionic acid content was higher in quadruple anaerobic reactor.In order to improve the fermentation ability of food waste wastewater,the food waste wastewater was pretreated and fermented.From the results of pretreatment fermentation,APG with pretreatment concentration of 0.10 g·(g·TS)^-1 can not only increase the total small molecular organic acid content of kitchen waste water to 48.86g/L,but also form fermentation broth with propionic acid as the main volatile fatty acid.The fermentation broth with lactic acid as the main product and total small molecular organic acid concentration of 47.75 g/l could be formed by pretreatment with 1.66 mg·L^-1 free nitrous acid(FNA).Tea saponin(TS)pretreatment had little effect on VFA production from food waste wastewater,but the proportion of butyric acid in small molecular organic acids could be increased to 66.98%at the concentration of 0.10 g·(g·TS)^-1.In order to verify the feasibility of anaerobic acidogenic fermentation and pretreatment for the recovery of dissolved carbon from kitchen waste wastewater,denitrification and denitrification experiments were carried out on kitchen waste wastewater,144h acidogenic fermentation broth and APG and FNA pretreated fermentation broth under the condition of C/N=8.It was found that the slow denitrifying substances of kitchen waste wastewater were basically transformed into fast denitrification by anaerobic acidogenic fermentation The two pretreatment methods were also helpful to improve the denitrification rate.