Characteristic Of Granular Sludge During Treatment Of Soy Sauce By Anaerobic Reactor

With the background of advocating low carbon circulation economic, as well as the attention of wastes recycling of our daily life, anaerobic biological treatment technology which has advantages of high load, low energy consumption and long sludge age, get more and more attention from people. During the same time, efficient anaerobic treatment technology become the hot spot to research on, and the key for anaerobic reactors to work efficiently is to cultivate anaerobic granular sludge which has the features of high efficiency and stability. This experiment compares the stable operation of the granular sludge UASB reactor of one sauce factory to the granular sludge IC reactor from a brewery. In order to provide the necessary theoretical basis and engineering data of operation of the anaerobic reactors, which could play principle and guild line role for the future anaerobic reactor, we analyzes the characteristics of two kinds of granular sludge as well as the stability differences and researches the reason lead to the differences between this two kind of granular sludge.From properties comparison of two kinds of granular sludge, we discover that the size and moisture of sauce granular sludge is bigger than beer's, but settling velocity, density and VSS/TSS value is smaller. We found the two kind of granular sludge mainly produce Methane filamentous bacteria from the scanning result of electron microscopy. Filamentous bacteria intertwine around each other into a mesh structure and wrap up granular sludge, at the same time filamentous bacteria from single granular sludge intertwine with others, which make size of granular sludge gathered into large one. Beer granular sludge mainly produces spherical methane bacteria which has dense internal structure. As the water matrix, the reactor operating temperature, the production process and reactor water distribution system is different, which leads two main reasons for differences in granular sludge. The temperature of beer production process is high and there is pre-acidification tank before enter IC reactor which has high concentration of acetic acid, all of this makes it has advantage to produce Methanosarcina. so the beer granular sludge is Methanosarcina-based. The sauce granular sludge which is intertwining with each other by filamentous bacteria is flexible and easy broken, but the structure is not as enough dense as granular sludge dominated by spherical bacteria ,That is why the settling velocity and density of sauce granular sludge is lower than the beer granular sludge, but higher moisture content.Contrasting the two kinds of particles on the ability to resist the impact, we find that when increase the organic load,the rate of the particles removing COD gets down and up, finally, gets stabled at a certain range. That is because with the percent of COD changing rapidly, the animalcule in particles needs time to adapt the new environment. The rate of sauce particles removing COD gets down rapidly when the density of COD increases to 8000 mg\L. However, the rate of beer particles removing COD gets down rapidly when the density of COD increases to 10000 mg\L. So comparing with sauce particle, beer particles have a better ability on resisting the impact.Contrasting the stability of the two particles in acidity, when pH is 6.5, both of the removing rates are above 90%, so are them when pH is 7.0. However, when pH is 4.5, the activation of anaerobe has been restrained completely, with both of the removing rates decreasing to 10% and CH4 production decreasing to zero. In alkalescency, when pH is 7.5, the removing rate of sauce particles surpasses 94%, while that of beer particles surpasses 96%. However, when pH is 12.0, the activation of anaerobe has been restrained completely, with both of them decreasing to 10% and CH4 production decreasing to zero.In acidity, the products of sauce particles are mainly bacillus, while that of beer particles are mainly short bacillus with single types. That's because the bacterium which produces methane filamentous bacteria can not adjust the environment in low acidity, and with the long selection of life form, acetic acid bacillus become the mainly bacterium. Both of the two kinds of particles become lax and crumbly after the experiments.