Study On Anaerobic Digestion Process Of Organic Waste Of Animals And Vegetation

A great deal of organic waste is produced when animals and vegetation provide people with meal,eggs,milk, and so on. If it is piled up directly, resources are wasted, water,air and environment are polluted.Anaerobic digestion process has benefits of energy,economy,ecology and environment protection, it is used in waste treating of animals and vegetable, widely. Anaerobic digestion processing is influenced by bacteria,protozoan and epiphyte ect. Its reactive mechanism is complex. Whether we can control every parameter of reactive process or not, it will affect the utilizing rate of material and firedamp content. Therefore, we must study it, seek optimal ferment process and parameter and offer science reference for the utilization of the waste of animals and vegetation.The domesticated sludge is loosen,floccules and black through domesticating under constant temperature condition which water is heated to 30±1℃ to ensure. By elector microscope, it can be seen that the sludge surface has many interspaces and holes; bacterial shape is bacilliform and ellipsoid; the quantity of bacteria has increased; the adaptability has built up. The domesticated sludge become super-bacteria of anaerobic digestion process, its propensity is in accordance with material feature.The single-phase batches anaerobic digestion experiments for cow waste,the stems and leaves of tomatoes and cucumbers have been performed at 30±1℃ constant temperature condition. The result shows that the mix material of the stems and leaves of tomatoes and cow waste has high H2S content,short produce-gas time,unstable reactive process in anaerobic digestion process.The pretreatment experiments of different density alkaline liquor marinating about the anaerobic digestion of cow waste and the mix of the stems and leaves of cucumbers and cow waste have been performed respectively, water marinating as comparison. The result shows that organic waste pretreated has the advantage of rapid degradation,short start-up time of reactor,stable reactive process,high utilizing rate of feedstock, and so on.The simulated anaerobic digestion process for the mix material of cow waste and the stems and leaves of cucumbers have been performed at twenty three kinds of working conditions with the ferment density range from 4% to 12%, the pH value from 5 to 9, the material proportion is cow waste: the stems and leaves of cucumbers from 1:5 to 5:1(weight proportion). The design of quadratic-rotation-orthogonality experiment was used for the simulated tests. In this paper, the effect of the ferment density, pH value and material proportion on gas value and CH4 content has been studied in particular. The mathematical model that qualitatively explains the relationships between the above three factors and the items indicated the anaerobic digestion process has been obtained. The effect of each factor on the items and its reason were analyzed. The main factors of the effect on gas value sequence is: the ferment density>the material proportion>the pH value and the effect on CH4 content sequence is: the material proportion>the ferment density>the pH value.