Using carrier surface loading to design heterotrophic denitrification reactors

Abstract

This article tests the theory of using nitrate carrier surface loading (SL) as the primary design criterion for heterotrophic denitrification of drinking water. Two load‐increase tests (flow rate and nitrate concentration) with a pilot‐scale heterotrophic biofilm reactor identified that the maximum SL was approximately 6 g nitrogen/m2/d and was controlled by the effluent nitrite concentration. A comparison of SL values obtained from the literature also showed that the maximum SLs were similar for a wide range of heterotrophic denitrification processes. All of the SL values are consistent, even though the empty bed contact time and the nitrate volumetric loading varied widely. The experimental results confirm that the electron donor should be supplied at the stoichiometric requirement to achieve simultaneously low concentrations of nitrate, nitrite, and organic carbon.

Nitrogen‐sparging assisted anoxic biological drinking water treatment system

“…The HRTs tested during Phase II were longer than in Phase I to compensate for the decreased surface area available for biofilm growth. Importantly, the maximum SLRs for the Gravel, Empty, and PVC contactors were within the range reported by Tang, Ziv‐El, et al (2011). Gravel could support the greatest $$$ {{\mathrm{NO}}_3}^{-} $$$ SLR among the tested packing media, so it could have a smaller reactor volume or operate at a greater flow rate for a given influent $$$ {{\mathrm{NO}}_3}^{-} $$$ concentration.…”

“…$$$ {{\mathrm{NO}}_3}^{-} $$$ removal and effluent $$$ {{\mathrm{NO}}_2}^{-} $$$ were more variable at greater SLRs and shorter HRTs, and this effect was more pronounced in the PVC and Empty contactors. Tang, Ziv‐El, et al (2011) found that maximum SLRs for heterotrophic denitrification were similar across a range of systems with different EBCTs and suggested its use in design because it considers $$$ {{\mathrm{NO}}_3}^{-} $$$ flux into the biofilm. Here, correlations between $$$ {{\mathrm{NO}}_3}^{-} $$$ removal and effluent $$$ {{\mathrm{NO}}_2}^{-} $$$ were of similar magnitude and significance for HRT and SLR, but the packing material strongly impacted performance (Figure 5, Table S3).…”

Potential of interactive multiobjective optimization in supporting the design of a groundwater biodenitrification process

“…This excess value is a reasonable upper bound: it should not imply any inhibition of denitrifying biomass when acetic acid is adopted as carbon source, as reported by Her and Huang (Her and Huang, 1995), who reached a 1600% carbon dosage excess. Furthermore, considering that Tang et al (Tang et al, 2011) observed 19 mgCOD/L in the effluent just with a 25% excess of carbon dosage (as CH3COONa), unacceptable carbon concentrations in the effluent should be limiting the optimal values of this design variable before reaching its upper bound, as desired.…”

Use of Ion Exchange Beads as a Bacterial Carrier for Biodenitrification

“…The World Health Organization and the European Economic Community have set standards of 11.3 mg/L nitrate as nitrogen (NO 3 – ‐N), which were adopted as a national standard for drinking water worldwide (Park & Yoo 2009). Consequently, nitrate removal is still a matter of significant concern in Europe, the United States (Tang et al 2011, Zhu et al 2010), and worldwide (Chen et al 2014, Wang & Wang 2013).…”