Effects of temperature on biodegradation characteristics of organic pollutants and microbial community in a solid phase aerobic bioreactor treating high strength organic wastewater

Abstract

The BOD removal rate and microbial community structure in a solid phase aerobic bioreactor using polyvinyl alcohol gel particles as packing material for the treatment of high strength organic wastewater were investigated at various temperatures. The BOD removal rate in the bioreactor increased when the temperature increased from 20 degrees C to 30 degrees C, 40 degrees C, and 50 degrees C, but it decreased when the temperature increased from 50 degrees C to 60 degrees C. Higher temperature enhanced the endogenous respiration of microbes in the bioreactor. The microbial community structure in the bioreactor was analyzed with quinone profile. The experimental results showed that the microbial community structure in the bioreactor was significantly affected by temperature. The dominant quinone of the microbes inhabiting the bioreactor was ubiquinone-8 at 30 degrees C, but that at 50 degrees C and 60 degrees C was menaquinone-7. It was estimated that the thermophilic Bacillus having menaquinone-7 dominated in the bioreactor at higher temperature. The microbial diversity in the bioreactor varied with temperature.