Performance And Microbial Community Dynamic Characteristics Of An Internal Circulation Reactor Treating Brewery Wastewater At Intermediate And Low Temperature

Brewery wastewater contained so high concentration of organic matter that could not discharge into the wave without disposing, or brewery wastewater would cause the serious environmental contamination. Brewery wastewater is treated mainly by biological methods, which usually controlled at intermediate temperature (30⁴0℃), but the studies at the low temperature was fewer. This study used the internal circulation reactor (IC) to treat the artificial brewery wastewater, and optimized the condition of the progress and studied the microbial community structure.A lab-scale internal circulation reactor (IC) fed by artificial brewery wastewater was operated with increasing volumetric loading rate (VLR) under 35℃and 20℃continuously. The reactor performance and the relationship between microbial community structure and bioactivity in the anaerobic sludge were investigated during the operation. At 35℃, the COD removal efficiency was above 85% while the maximum volumetric loading rate could be up to 20 kg·(m³·d)^-1, and the maximum specific methanogenic activity (SMA) of the reactor was 210 mL·(g·d)^-1. But at 20℃, the maximum volumetric loading rate (VLR) only could be up to 10 kg·(m³·d)^-1, and the COD removal efficiency was above 80%, and the maximum specific methanogenic activity of the reactor was 62 mL·(g·d)^-1.This study used PCR-DGGE and cloning technology to analyze the microbial community structure and bioactivity in the anaerobic sludge, and the relationship between them. The results from the dehydrogenase and the bacteria DGGE at 35℃experiments demonstrated that the dehydrogenase variation tendency was positively correlated to total light intensity of the whole bacteria DGGE bands for each sample. The total light intensity of the whole bacteria DGGE bands can use as a referential index for biomass liveweight in anaerobic system. Moreover, this paper found that the coenzyme F₄₂₀ content was related to the relative abundance of Methanosaeta based on coenzyme F₄₂₀ and archaebacteria DGGE analysis. As the volumetric loading rate increased, Methanosaeta became dominant increasingly, which was accompanied by the coenzyme F₄₂₀ content increasing. The content could be up to 0.16μmol·g^-1, meanwhile, the superiority of Methanosaeta became very especially obvious; UPGAMA analysis and Shannon index also confirmed the dynamic changes of microbial community structure during the operation. And at 20℃, the microbial community structure including bacterium and archaebacteria both were stable, and the similarity were high.Compared with the index of Margalef richness and the dominance index about the microorganism, both at medium and low temperature, the index of Margalef richness of bacterium was bigger than archaebacteria, but the dominance index of archaebacteria was higher than bacterium. At last, clustering analysis of DGGE patterns about different microorganism at different temperature were also analyzed at this paper, except the bacterium at the low temperature contained two ethnic groups, others contained three ethnic groups.