Experimental Study On The Treatment Of Food Wastewater In Mesophilic Anaerobic Digestion

Food wastewater is rich in carbohydrates, protein and lipids and other organic matter, and it is the main source of organic phase of municipal solid waste. The organic waste accounts for about40%to60%. The high content of organic compounds, water content and ease of deterioration make it both a pollutant and a recyclable resource.To make the food waste harmless, recyclable and less in amount, we use the Upflow Anaerobic Sludge Blanket (UASB) reactor for simulating anaerobic digestion of food waste on the degradation of analog processing. And we discussed the influent organic concentration, hydraulic retention time’s influence on anaerobic digestion for food waste anaerobic digestion pilot project to provide guidance to the practical application.The results showed that:the cultivation of anaerobic sludge and the domestication process should ensure there is enough water alkalinity in order to prevent acidification of the pollutants that are not caused by pH value of the VFA into decline, thereby enhancing the system stability.During the inspection of the influence of influent organic concentration on the degradation of food waste anaerobic digestion, we found the amount of gas production and methane production increased with the influent organic load increased rapidly。When the influent organic concentration is12000mgCOD/L, the maximum gas production16.5L/d is reached, the corresponding methane content of8.10L/d, COD removal rate was97.29%, the effluent VFA concentration of7.8mmol/L.In this process, the addition of NaHCO3and NH4+from the decomposition of protein to participate in regulating the alkalinity to balance the maintain system, the basic reactor was maintained at6.89-7.31in pH. microbial growth and metabolism of the reactor were in good condition. When further improving the influent organic concentration to14000mgCOD/L, the gas production decreased, and the effluent VFA concentration was11.9mmol/L, at this time it is not appropriate to raise the organic concentration, by Studying the impact of different hydraulic retention time (HRT) on the food waste anaerobic digestion, it was found that by extending HRT, influent organic matter and microbial would contact more fully, as a result a significant improvement in organic matter removal was observed and gas production has gradually picked up, but marginally. It showed that high concentrations of food waste water is suitable for the growth of anaerobic microorganisms and it is feasible in a certain volume of the organic load degradation of food waste to use anaerobic digestion process.