BIOAVAILABILITY OF DISSOLVED ORGANIC NITROGEN IN WWTP EFFLUENT: A TRUCKEE RIVER CASE STUDY

摘要

Total maximum daily loads (TMDLs), waste load allocations (WLAs), and National PollutionrnDischarge Elimination System (NPDES) permits for total nitrogen (TN) generally assume that allrnnitrogen in the effluent is equally available for uptake by aquatic biota and do not distinguishrnbetween organic and inorganic forms of nitrogen. Because many wastewater treatment plantsrn(WWTPs) employ biological nutrient removal systems, including nitrification/denitrification forrninorganic nitrogen removal, dissolved organic nitrogen (DON) can comprise a significant TN inrnthe effluent. Removal of this seemingly refractory DON requires expensive advanced treatment.rnAn example of Publicly Owned Treatment Works (POTWs) facing this dilemma is the TruckeernMeadows Water Reclamation Facility (TMWRF) in Reno, Nevada, which discharges to thernTruckee River. This paper discusses the challenges TMWRF is facing related to DON, brieflyrndescribes DON treatability and fate studies performed at TMWRF, and explains the approachrnand preliminary results of DON bioavailability studies conducted to determine the impacts ofrnTMWRF effluent DON on the Truckee River.