Laboratory studies were conducted and modeled to evaluate whether refractory organic nitrogen in tertiary-treated wastewater effluent could become bioavailable by conversion to mineral forms. Multiday incubations of effluent collected from the Branford and New Haven, Connecticut, waste water treatment plants (WWTP) revealed low but steady conversion of organic nitrogen to nitrate (NO3−). In Branford, the principal form of organic nitrogen was dissolved, and in New Haven it was particulate. Modeling suggested that in both the cases conversion to NO3− from organic forms occurred at several per cent per day, and appeared to happen via the intermediary NH4+. The results suggest that organic nitrogen may be an important source of bioavailable N, contributing to the problem of hypoxia in Long Island Sound and other estuaries.
This is a preview of subscription content, log in to check access
Funding was provided by the Long Island Sound Fund administered by the Connecticut Department of Energy and Environmental Protection, through the sale of Long Island Sound license plates and contributions.
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no competing interests.
APHA (2002) Standard methods for the examination of water and wastewater, 18th edn. American Public Health Association, Washington, DCGoogle Scholar
APHA(2005) Standard methods for the examination of water and wastewater, 21st edn. American Public Health Association, Washington, DCGoogle Scholar
Keller JV, Leckie JO, McCarty PL (1978) Investigation of soluble organic nitrogen compounds in municipal secondary effluent. J Water Pollut Control Fed 50:2522–2529Google Scholar
Kerner M, Spitzy A (2001) Nitrate regeneration coupled to degradation of different size fractions of DON by the picoplankton in the Elbe Estuary. Microbiol Ecol 41:69–81Google Scholar
Koopmans DJ, Bronk DA (2002) Photochemical production of dissolved inorganic nitrogen and primary amines from dissolved organic nitrogen in waters of two estuaries and adjacent surficial groundwaters. Aquat Microb Ecol 26:295–304CrossRefGoogle Scholar
Parkin GF, McCarty PL (1981) A comparison of the characteristics of soluble organic nitrogen in untreated and activated-sludge treated wastewaters. Water Res 15:139–149CrossRefGoogle Scholar
Pehlivanoglu E, Sedlak DL (2004) Bioavailability of wastewater-derived organic nitrogen to the alga Selenastrum Capricornutum. Water Res 38:3189–3196CrossRefGoogle Scholar
Pehlivanoglu-Mantas E, Sedlak DL (2006) Wastewater-derived dissolved organic nitrogen: analytical methods, characterization, and effects - a review. Crit Rev Environ Sci Technol 36:261–285. https://doi.org/10.1080/10643380500542780CrossRefGoogle Scholar
Qasim SR (1999) Wastewater treatment plants: planning, design, and operation, 2nd edn. CRC Press, Boca Raton, FLGoogle Scholar
Randtke SJ, McCarty PL (1978) Variations in nitrogen and organics in wastewaters. J Environ Eng Div-ASCE 103:539–550Google Scholar
Randtke SJ, McCarty PL (1979) Removal of soluble secondary-effluent organics. J Environ Eng Div-ASCE 105:727–743Google Scholar
Scully FE, Howell GD, Penn HH, Mazina K, Johnson JD (1988) Small molecular weight organic amino nitrogen compounds in treated municipal waste-water. Environ Sci Technol 22:1186–1190CrossRefGoogle Scholar
Seitzinger SP, Sanders RW (1997) Contribution of dissolved organic nitrogen from rivers to estuarine eutrophication. Mar Ecol-Prog Ser 159:1–12CrossRefGoogle Scholar
Seitzinger SP, Sanders RW, Styles R (2002) Bioavailability of DON from natural and anthropogenic sources to estuarine plankton. Limnol Oceanogr 47:353–366CrossRefGoogle Scholar
Stepanauskas R, Jorgensen NOG, Eigaard OR, Zvikas A, Tranvik LJ, Leonardson L (2002) Summer inputs of riverine nutrients to the Baltic Sea: bioavailabity and eutrophication relevance. Ecol Monogr 72:579–597CrossRefGoogle Scholar
Stepanauskas R, Leonardson L, Tranvik LJ (1999) Bioavailability of wetland-derived DON to freshwater and marine bacterioplankton. Limnol Oceanogr 44:1477–1485CrossRefGoogle Scholar