Characteristic Studies On Anaerobic Fermentation For Kitchen Wastewater

Recently, with the development of our economy and increase of residents’ income,the amount of garbage generated, including food waste increased rapidly. It lacks oftimely and effective treatment of food waste. So it brings a lot of environmental andsafety issues. Recently, it is very popular that food waste is treated by anaerobicfermentation technology in practical application. But there are also some issues，such assystem instability，lower gas production rate，readily to acidification. So it also needssome further researches to investigate. So，anaerobic fermentation influencing factor ofkitchen wastewater was studied， including multi-stage anaerobic fermentationexperimental study and single-stage anaerobic fermentation of food waste food. It is thatto realize the reduction and energy utilization of kitchen wastewater.Firstly, anaerobic fermentation characteristic of kitchen wastewater was studied.Inorder to realize the reduction and energy utilization of kitchen wastewater，anaerobicfermentation characteristic of kitchen wastewater was studied. Influences of the influentconcentration，inoculums ratios, the initial pH，hydrolysis acidification time andinteractions between them on anaerobic digestion gas production ratio of kitchenwastewater were researched by L27（313）orthogonal tests. The results show that theanaerobic digestion has good effect of gas production when the influent concentration is60g·L-1，inoculums ratios is40%, the initial pH is7.0and the hydrolysis acidificationtime is1d，the biogas production ratios can reach0.6318L·g-1COD. The influencingeffects of factor are followed as inoculums ratios>initial pH>hydrolysis acidificationtime>influent concentration，and the significant sequence is inoculums rates，effects ofinteraction of the influent concentration and hydrolysis acidification time，effects ofinteraction of inoculums ratios and the initial pH of the inlet.On this basis, process performance of food waste mesophilic anaerobic digestion isevaluated in different operation conditions，such as the initial pH and dosing ratio.Theireffects on biogas production and liquid-phase indexes，and influencing pathways undervarious operation conditions have been approached. Controlling pH to a suitable scopeabout6.8~7.4can shorten the time of hydrolysis and acidification，increase thehydrolysis and acidification rates，promote the degradation of VFA，ensure the processof the methanation reaction. Controlling dosing ratio to a suitable scope about2.5%, the biogas production ratios can reach1.32L·g-1COD.Food waste that is processed after the Up-flow Anaerobic Sludge Blanket (UASB)device, can obtains better treatment effect. The first-stage anaerobic HRT control in40days， Controlled conditions of the second-stage anaerobic HRT is15days， systemCOD removal rate of the total is91%~93%.