Nitrification of urine for H2S control in pressure sewers

Abstract

Urine separation has great interest from different water boards in the Netherlands. Separate treatment of urine will lead to lower nitrogen emissions from wwtp's with substantial energy savings. Furthermore, it is possible to recover phosphates and remove medicine residues and hormones from urine. In this project, urine collected with urinals and urine-separation toilets, was nitrified in a CSTR. An average ammonium conversion to nitrate of 97% was achieved. The nitrate rich urine was pumped into a small pressure sewer to prevent sulphate reduction. H2S in the gas phase of the sewer system was reduced significantly. From the required amount of nitrate (for >95% H2S reduction) the feasibility of urine nitrification for H2S control was determined. The costs of the concept mainly depend on transport and addition of sodium hydroxide. If urine can be collected undiluted (minimal 3 g N/l) and can be stored in big storage tanks (minimal 10 m3), nitrification of urine can be an alternative for Nutriox addition to pressure sewers.

State of the art of urine treatment technologies: A critical review.

“…(2016) Complete nitrification PBBR 8 27 600 < 50 < 0.7 Feng et al. (2008) Biofilm 2 7 15-25 800 < 50 < 1.8 Oosterhuis and van Loosdrecht (2009) SBR 3 7.3-7.6 25 1500 1100 - 4 Jiang et al. (2011) SBR 3 ≥ 6.5 - 1270 5 600-700 0.6-0.7 Mackey et al.…”

“…In fact, using a larger water volume for urine flushing will easily achieve sufficient dilution of ammonia and salt, except in places like Hong Kong, where toilets are flushed with seawater. For practical implementation, especially in on-site settings, dosing of alkalinity is the main challenge ( Oosterhuis and van Loosdrecht 2009 ).…”

“…In the latter case, nitrate and nitrite can replace sulfate as electron acceptor, thereby preventing biogenic sulfide corrosion ( Jiang et al. 2011 , Oosterhuis and van Loosdrecht 2009 ).…”

Bio-electrochemical COD removal for energy-efficient, maximum and robust nitrogen recovery from urine through membrane aerated nitrification

“…Different reactor systems have been used for partial or full urine nitrification: continuous stirred tank reactors ( Oosterhuis andvan Loosdrecht, 2009 , Udert et al, 2003 ), sequencing batch reactors Chen et al, 2017, ( Jiang et al, 2011, Mackey et al, 2010, Udert et al, 2003, moving bed biofilm reactors ( De Paepe et al 2018 ;Udert et al, 2003 ) and membrane bioreactors ( Coppens et al, 2016 ;Fumasoli et al, 2016 ). In this study, urine nitrification was performed in a membrane-aerated biofilm reactor (MABR), given its high oxygen utilization efficiency, compact design and compatibility with the reduced gravity conditions in Space ( Côté et al, 1988 ;Jackson et al, 2009 ;Martin and Nerenberg 2012 ;Nerenberg 2016 ).…”

Decision support in urban water management based on generic scenarios: The example of NoMix technology

“…Moreover, the methodology does not cover the use of NoMix technology to optimize the central system, e.g. by peak shaving (Rauch et al, 2003) or in-house nitrification, in order to protect anaerobic sewers from corrosion (Oosterhuis and van Loosdrecht, 2008; for an overview of the role of nitrate to protect sewers against corrosion, see e.g. Yang et al, 2004).…”