Anaerobic ammonium oxidation (anammox) requires 60% less oxygen and no external organic carbon compared to conventional biological nitrogen removal (BNR). Nevertheless, full-scale installations of anammox are uncommon, primarily owing to the lack of well-established process monitoring and control strategies that result in stable anammox reactor performance. The overarching goal of this study was to develop and apply molecular biomarkers that link microbial community structure and activity to anammox process performance in a bioreactor fed with actual anaerobic digestion centrate from a full-scale operational wastewater treatment facility. Over long-term operation, Candidatus "Brocadia sp. 40" emerged as the dominant anammox population present in the reactor. There was good correspondence between reactor nitrogen removal performance and anammox bacterial concentrations. During the period of reactor operation, there was also a marked shift in biomass morphology from discrete cells to granular aggregates, which was paralleled by a shift also to more stable nitrogen removal and the succession and establishment of bacteria related to the Chlorobi/Bacteroidetes superfamily. Based on batch assays, hydrazine oxidoreductase (hzo) expression and concentrations of the 16S-23S rRNA intergenic spacer region (ISR) were good quantitative biomarkers of oxygen- and nitrite-mediated inhibition. When applied to a continuous anammox reactor, both molecular biomarkers show promise as monitoring tools for "predicting" reactor performance.

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The process of air stripping/absorption was studied at pilot scale at temperatures ranging between 23 and 75°C using ammonia in artificial and natural centrate. The process was more effective at high temperatures and became pH insensitive beyond a critical pH, which was found to drop as the operating temperature increased. Thus, at high temperatures, shorter packing height and lower pH are required to achieve the same ammonia removal. The Onda correlations predicted well the mass‐transfer properties of 25 mm (1 in.) and 32 mm (1.25 in.) nominal size packing in the ranges of 40 to 60°C and 53 to 61°C, respectively. The Norman/Sherwood–Holloway correlations predicted well the mass‐transfer properties for the former and poorly underpredieted the latter packing. The Onda correlations are recommended for preliminary design of stripping/absorption systems within the preceding temperature ranges.

Amongst the principal separation processes used to treat effluents in the water industry is the sedimentation of solid particulates from the carrier fluid known as mixed liquor by the force of gravity. New York City DEP is in the process of upgrading its Upper East River water pollution control plants (WPCP's) to incorporate biological nitrogen removal (BNR). The rectangular final settling tanks (FSTs) are a central link in the treatment process and often times a limiting factor in terms of the solids handling capacity especially when high throughput requirements need to be met. The objective of this study was to develop a 3D Computational Fluid Dynamics (CFD) model based on the exact geometry of the existing Gould II type 1170 S. Xanthos et al.FSTs in Battery "E" at the Wards Island WPCP and calibrate and validate it with insitu data collected at the site. The goal of this study is to illustrate how the different modeling approaches applied on the physical phenomena that take place in the tank affect the outcome of a CFD model and its predictions. It is common for internal baffles to be added at the inlet and within the tank to handle high flow requirements such as wet weather storms. This model has been used as a tool to assess the internal behavior of such baffles and assess the clarifier's performance based on different inlet baffle configurations.