| The anaerobic baffled reactor (ABR) comprises a series of vertical baffles to forcethe wastewater to flow under and over them, and ABR may be classified as a series ofcompartment. It is simple in design and improved biomass retention within reactor. Inthis experiment, the reactor is a hybrid anaerobic baffled reactor in which added theaerobic precoating treatment filler. This reactor system has been reported to have manyadvantages over other well established reactor systems; therefore ABR is one of themany types of high-rate anaerobic reactors presently attracting growing interests. In thisexperiment, the effective volume of ABR is1cubic meter, which divided into fourcompartments with the same size. Each compartment has a downward flow chamberand a upward flow chamber, and the volume ratio is1:2. In each compartment, theupward flow chamber is added with hollow ball filler. The main content of this studyincludes two aspects, the first aspect is the variation of the performance parameters onthe start-up of ABR, and the second aspect is the characteristic of the granular sludge inABR.The results of this paper show that:（1） The start-up of ABR adopts the low load combination with adding aerobicprecoating filler. The concentration of COD is about400mg/L, and HRT is24h、12h、6h、3h and8h in turn. Organic load increases from0.38kgCOD/(m3·d) to3.42kgCOD/(m3·d), and turns into1.28kgCOD/(m3·d) then HRT is8h. ABR wassuccessfully start-up in70days, when the COD removal rate reaches more than80%,and keeps on for more than a week. ABR was very stable to organic load, organic loadrate was directly proportional to organic removal load. The removal rate of COD wouldmove from front to back, with the shortening of HRT.1#and2#compartment playedimportant role of removal COD, and3#and4#compartment played a stabilizing role ofeffluent. The pH of each compartment increased with the flow direction, and the VFAof each compartment decreased with the flow direction. The VFA of effluent stabilizedat about60mg/L, and the alkalinity of effluent was maintained at161~213mg/L. Theratio of VFA/BA increased with the flow direction, which implied the buffer capacityagainst with pH of each compartment was good and increased along the flow direction.For the treatment of sewage in low concentration and low temperature, it could lowerthe effect of the temperature for the reactor to add aerobic precoating filler which to increase the total amount of biological in the reactor, and lay insulation materials.Adding aerobic precoating filler in ABR reactor could improve the amount of sludgereactor and the separation performance of the gas、 water and mud in the reactor, andaccelerate the speed of start-up.（2） The start-up of ABR adopts the low load. Granulation degree of sludge ofeach compartment reduced along the direction of flow. The granulation degree of1#compartment was the highest, which reached87.6%, and granular sludge particle sizegrading obviously. The SVI of sludge of each compartment increased along the flowdirection, which implied the performance of sludge settling down gradually weakened.The surface of the granular sludge was relatively loose in1#and2#compartment, and itwas relative density in3#and4#compartment. Each compartment had obviousphenomenon of population and biological phase separation. The dominant species of thefront compartment was the hydrolysis acid-producing bacteria, and that of the backcompartment is methanogen. Coenzyme F420of each compartment increased along theflow direction, and was directly proportional to the pH. The MLVSS、 MLSS andMLVSS/MLSS of each compartment showed the phenomenon that the values of bothends compartments were higher and the values of intermediate compartment were lower.The hydraulic characteristics、microbial community types、starting mode、the pH andthe temperature had certain influence on the cultivation of granular sludge. The studyconcluded, adding aerobic precoating filler and start-up with lower load was in favor ofcultivating granular sludge at low temperature, and also can quickly and successfullycultivated the granular sludge. |
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