Studies On The Start-up Of Anaerobic Baffled Reactor(ABR), Granular Sludge Characteristics And Dye Wastewater Treatment

The start-up of anaerobic baffled reactor and the fractal character of the ripened granular sludge in the reactor were studied. The reactor was used to deal with dye wastewater. The disposal effects and influent factors were examined. The results were as follows:The start-up of anaerobic baffled reactor at the temperature of 20-30℃ were examined in this study. Through five-stage experiments during 169 days, the volumetric loading rate (VLR) of the influent reached around 4.38kgCOD/m~3·d, and with suitable values of the effluent COD, VFA and pH. Abundant granular sludge with good characteristics were existed in the reactor, such as granular size 2~3.8mm, more than 20m/h of settling velocities and MLVSS/MLSS above 65%. However, different SVI values were found in each compartment. The microscopic analysis results showed that cooperative anaerobic microbial communities distributed within different compartments. The dominant bacteria in the compartment one were zymogen, and much filamentous methanogenic bacteria that can absorb acetic acid were also observed. Towards the ends of the reactor, the dominant bacterial populations shifted stepwise to methanogenic bacteria in granular sludge, and appearing lots of protozoan and metazoan. As to single granular sludge with different shape, the air holes were in its uneven surface. The fewer microbes were found in the core of the granular than on the surface, while the bacteria secretion and inorganic compounds appeared oppositely.Based on the SEM-images of mature granular sludge in ABR, the research process on fractal characteristics of these granules was built. The treatment and fractal dimensions calculation of the images were carried on through Photoshop, Newscan and Fips programs. The results showed that the boxing-counting dimensions of the mature granular sludge were more than 1.85, and the granules formed in the third and fifth compartments were more compact. The boundaries of the same granular sludge were fractal with the fractal dimensions of approximate 1.1, demonstrating the irregularity of the boundaries or surface, furthermore the surface of these granules formed in the first and fifth compartments was more irregular. It seemed that the compass dimensions of the granules boundary were a proof of irregularity of their surface. Moreover, there existed two scale scopes incalculating the compass dimensions of each granule, especially some of them with a span of one order of magnitudes.The more compact of the granular sludge internal structure was demonstrated by its higher boxing-counting dimensions than outer surface, furthermore, the results of D3 calculated by area-gyration radius method strengthened it and showed the more irregularity and complexity of islands within granules. It seemed no rules were found among the fractal dimensions (D3) from Sandbox method. Less than 1.0 of the boundary dimensions (D4) by area-perimeter method could result from the inverse proportion between the perimeters and areas of many little islands in or on the granules.The constitution of the inlet nutrient content was glucose (1.36g/L) + NaHCC>3 (1.11 g/L) + trace element when the ABR was used to deal with direct fast light black G With the increase of the dye concentration, the removal rate of the dye ascended first and then decreased. The microorganism observed in the ABR changed. Many protozoans were found in the first, second, third compartment. More swimming beasties and least microorganisms were found in the fourth and fifth compartment. Granular sludge in the frontal compartments was divided greatly and few bubbles were found, which meant that with the increasing of dye load there was a tendency of homology in the microorganism of the front compartments and the granular configuration was still different.The great influence of HRT to the removal rate of the dye was found. With the increase of inlet flux, the average removal rate of the dye downtrend tended to descend and pH stabilized around 6.65. The removal rate of the dye was 89 percent when the inlet flux was 30ml/min. The mic...