Evaluation of microcosmic phenomena on enhancing main-stream biological nutrient removal by side-stream phosphate recovery
HAO Xiaodi1,,, LI Ji1, ZHAO Zicheng1, LIU Jie2 1.Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies, Beijing Advanced Innovation Centre of Urban Design, Beijing University of Civil Engineering and Architecture, Beijing 100044, China 2.Beijing Capital Eco-Environment Protection Group Co. Ltd., Beijing 100044, China
Abstract:External carbon source is effective on improving the efficiency of biological nutrient removal (BNR) with low-concentration influent organic loads, but it must increase operational costs and CO2 emission. Under the circumstance, side-stream phosphate removal (P-removal) on enhancing main-stream BNR should become an alternative to solve the BNR limitation by low-concentration influent carbon source. A modified UCT process with the side-stream P-removal unit was applied for recovering phosphate only by adjusting pH in this study. The experimental results reveal that the optimal side-stream ratio was 15% and pH at 9.5~10.5 for side-stream supernatant could achieve the highest P-recovery efficiency. The experiment results also indicated that the side-stream P-removal could enhance the main-stream BNR, and then associated sludge characteristics, activities of related bacteria as well as the species and abundance of dominant bacteria were experimentally studied and evaluated. With the experiments, microcosmic phenomena on enhancing main-stream biological nutrient removal by side-stream phosphate recovery was analyzed, and the performance of sludge sedimentation, extracellular polymer substances (EPS), the activity and abundance of microbials (including nitrifiers, phosphorus-accumulating organisms (PAOs) and denitrifying phosphorus removing bacteria (DPB)) were mainly analyzed and evaluated. The conclusions would be useful for promoting the practical application of the side-stream P-removal on enhancing the main-stream BNR. Key words:side-stream phosphate recovery/ biological nutrient removal/ nitrifiers/ denitrifying phosphate removal/ sludge characteristics/ dominant microbials.
图1实验小试装置工艺流程 Figure1.Lab-scale configuration of the bioreactors
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1.Sino-Dutch R&D Centre for Future Wastewater Treatment Technologies, Beijing Advanced Innovation Centre of Urban Design, Beijing University of Civil Engineering and Architecture, Beijing 100044, China 2.Beijing Capital Eco-Environment Protection Group Co. Ltd., Beijing 100044, China Received Date: 2021-08-17 Accepted Date: 2021-10-27 Available Online: 2021-12-22 Keywords:side-stream phosphate recovery/ biological nutrient removal/ nitrifiers/ denitrifying phosphate removal/ sludge characteristics/ dominant microbials Abstract:External carbon source is effective on improving the efficiency of biological nutrient removal (BNR) with low-concentration influent organic loads, but it must increase operational costs and CO2 emission. Under the circumstance, side-stream phosphate removal (P-removal) on enhancing main-stream BNR should become an alternative to solve the BNR limitation by low-concentration influent carbon source. A modified UCT process with the side-stream P-removal unit was applied for recovering phosphate only by adjusting pH in this study. The experimental results reveal that the optimal side-stream ratio was 15% and pH at 9.5~10.5 for side-stream supernatant could achieve the highest P-recovery efficiency. The experiment results also indicated that the side-stream P-removal could enhance the main-stream BNR, and then associated sludge characteristics, activities of related bacteria as well as the species and abundance of dominant bacteria were experimentally studied and evaluated. With the experiments, microcosmic phenomena on enhancing main-stream biological nutrient removal by side-stream phosphate recovery was analyzed, and the performance of sludge sedimentation, extracellular polymer substances (EPS), the activity and abundance of microbials (including nitrifiers, phosphorus-accumulating organisms (PAOs) and denitrifying phosphorus removing bacteria (DPB)) were mainly analyzed and evaluated. The conclusions would be useful for promoting the practical application of the side-stream P-removal on enhancing the main-stream BNR.