Coupling seed sludge evolution with reactor spatial optimization: Simultaneous nitrogen and phosphorus removal from real municipal wastewater
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Comparison of Scale in a Photosynthetic Reactor System for Algal Remediation of Wastewater
Published on: March 6, 2017
Yunjing Wang1, Tianyuan Du2, Weikang Qi2
1National Engineering Laboratory for Advanced Municipal Wastewater Treatment and Reuse Technology, Key Laboratory of Beijing for Water Quality Science and Water Environment Recovery Engineering, Beijing University of Technology, Beijing 100124, China; Beijing Drainage Group Co., Ltd., Beijing 100044, China.
Abstract:
Achieving simultaneous nitrogen and phosphorus removal in continuous-flow municipal wastewater remains challenging. This study evaluated an aerated-volume-optimized continuous self-circulating fluidized bed (ACOAAP-Zier) treating real municipal wastewater inoculated with either flocculent sludge (R_floc) or anaerobic granular sludge (R_AnGS). Distinct seed-sludge evolutionary trajectories fundamentally shaped the structural and functional development of microbial aggregates. R_floc followed a bottom-up aggregation pathway and formed predominantly small-to-medium aggregates, whereas R_AnGS underwent a physical "top-down" structural reconstruction and retained a greater proportion of large aggregates. Under comparable conditions, the 500-1000 µm and > 1000 µm fractions in R_AnGS (P3) were 3.0- and 5.4-fold higher than in R_floc (P2), respectively. The resulting structural heterogeneity provided differentiated ecological niches for functional microorganisms. P2 exhibited superior ammonia oxidation, whereas P3 favored the enrichment of denitrifying and phosphorus-removing microorganisms, with denitrifying polyphosphate-accumulating organisms (DPAOs) being approximately 3.1 times higher than that in P2. Consequently, enhanced phosphorus removal and coupled nitrogen-removal pathways were achieved. Aggregate size was significantly positively correlated with polyphosphate-accumulating organisms abundance. These findings provide a basis for optimizing continuous-flow biological nutrient removal in municipal wastewater treatment.
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