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Effects of Specific Surface Area of Artificial Carriers on Carbon Metabolism Activity of Biofilm

Biofilm technology has been applied to polluted water treatment. The functional characteristics of biofilm play key roles in the decontamination efficiency and are affected by the physicochemical properties of the carrier surface. Previous studies reported that the larger the specific surface area of the artificial carrier, the more biofilms there are attached to its surface. However, the coupling relationship between the metabolic activity of biofilm and the specific surface area of carrier remained limitedly studied. Herein, five carriers with a gradient of specific surface areas were selected to incubate biofilms in two low-pollution rivers for 44 days, and a BIOLOG ECO microplate was used to analyze the metabolic activity of biofilm. Results demonstrated that the carbon metabolic capacity of biofilm fluctuates with the increase in the specific surface area. In Xuanwu Lake, the carbon metabolism rate of biofilm demonstrated a linear correlation with a specific surface area. In Donghu Lake, there was a trend of a single hump because of mass transfer limitation. In different water bodies, the carbon metabolic activity of biofilm demonstrated different trends with the change of specific surface area, and mass transfer limitation should be considered. For the classified carbon sources, there was a threshold (with Xuanwu Lack of 7500 m2/m3 and Donghu Lack of 5000 m2/m3) to make the biofilm achieve the best utilization ability of classified carbon sources. Nevertheless, the change of carriers’ specific surface area had little effect on the community structure of biofilm.