WEF/WERF study of BNR plants achieving very low N and P limits: evaluation of technology performance and process reliability

Abstract

The Water Environment Research Foundation (WERF) funded a two-year comprehensive study of nutrient removal plants designed and operated to meet very low effluent total nitrogen (TN) and total phosphorus (TP) concentrations. WERF worked with the Water Environment Federation (WEF) to solicit participation of volunteers and provide a forum for information exchange at workshops at its annual conferences. Both existing and new technologies are being adapted to meet requirements that are as low as 3.0 mg/L TN and 0.1 mg/L TP, and there is a need to define their capabilities and reliabilities in the real world situation of wastewater treatment plants. A concern over very low daily permits for ammonia caused the work to be extended to include nitrification reliability. This effort focused on maximizing what can be learned from existing technologies in order to provide a database that will inform key decision makers about proper choices for both technologies and rationale bases for statistical permit writing. To this end, managers of 22 plants, 10 achieving low effluent TP, nine achieving low effluent TN, and three achieving low effluent NH(3)-N, provided three years of operational data that were analyzed using a consistent statistical approach. Technology Performance Statistics (TPSs) were developed as three separate values representing the ideal, median, and reliably achievable performance. Technological conclusions can be drawn from the study in terms of what can be learned by comparing the different nutrient removal and nitrification processes employed at these 22 plants.

Policy Utopias for Nutrient Credit Trading Programs with Nonpoint Sources

“…However, in the first phase of the program the association found that it could achieve nutrient discharge reduction more cheaply through operational and minor capital improvements; the required reduction was not severe enough to stimulate demand for credits. When regulatory requirements for trading are weak and firms are able to apply on‐site technologies (Bott et al ., ), demand for credits is low.…”

Endogenous Nitrous Oxide Emission for Denitrifiers Acclimated with Different Organic Carbons

“…The technologies for biological wastewater treatment has evolved from conventional biological nutrient removal, through enhanced biological nutrient removal to the limit of present technology [1][2][3][4]. For sensitive water bodies, discharging of wastewater with total nitrogen (TN) concentration of 3 mg/L and total phosphorus (TP) of 0.1 mg/L or even lower has been set as discharging standard [2][3][4].…”

“…For sensitive water bodies, discharging of wastewater with total nitrogen (TN) concentration of 3 mg/L and total phosphorus (TP) of 0.1 mg/L or even lower has been set as discharging standard [2][3][4]. The biological removal of nitrogen (N) is mainly achieved by combining nitrification and denitrification conventional processes.…”

Evaluation of leachate dissolved organic nitrogen discharge effect on wastewater effluent quality

“…The TN removal efficiencies of the four WWTPs and their summary statistics (50th, 95th, and 99th percentiles) for daily performance based on historical plant data over a three-year period were published by Bott et al (2012). The 95th percentile is considered to capture the ''reliable" achievable performance for a WWTP (Bott et al, 2012).…”

“…The 95th percentile is considered to capture the ''reliable" achievable performance for a WWTP (Bott et al, 2012). The 50th percentile values represent the median as opposed to the average.…”