Evaluation of separate urine collection and treatment to augment existing wastewater treatment works.
Simultaneous increases in wastewater loads and effluent quality demand improved nutrient removal techniques. A simple technique for nitrogen removal is post-denitrification with methanol. The tradeoff between better effluent vs. methanol consumption is debatable. Methanol dosing is not only un-sustainable in the long term, but the cost of methanol is also becoming increasingly important. Urine contains 80% of the total nitrogen (N) and 50% of the phosphate in wastewater. Separate collection and treatment of urine could improve existing treatment works and diminish the need for post-denitrification. In this paper, a nitritation-denitrification process is proposed where 20-30% of the N in urine is removed with the COD available in urine. The treated urine consists of ammonium-nitrite, which is to be introduced to the anoxic zone of a conventional treatment plant. Optimal denitrification via nitrite is possible with COD from other wastewater sources. The case study presented here shows that 40-50% urine separation and improvement of the flow scheme would improve effluent quality from 19 to 10 g N/m3, which would eliminate the need for post-denitrification.
Wilsenach
J A
JA
Department of Biotechnology, Delft University of Technology, Julianalaan 67, 2628 BC, Delft, The Netherlands.
van Bragt
W P M
WP
de Been
P
P
van Loosdrecht
M C M
MC
D019149:Bioreactors; D002138:Calibration; D009573:Nitrites / Q000378:metabolism*; D009584:Nitrogen / Q000302:isolation & purification / Q000378:metabolism; D010710:Phosphates / Q000032:analysis; D000644:Quaternary Ammonium Compounds / Q000032:analysis / Q000378:metabolism; D012722:Sewage; D014556:Urine / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D009573:Nitrites; D010710:Phosphates; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D009584:Nitrogen