Nitrogen removal of high strength wastewater via nitritation/denitritation using a sequencing batch reactor.
The sequencing batch reactor (SBR) process concept was applied to achieve efficient ammonium removal via nitrite under both laboratory and pilot-scale conditions. Both sets of experimental results show that without pH control or carbon addition the nitritation process consistently converted approximately 50% of the ammonium from biosolids dewatering liquids to nitrite with hydraulic retention times (HRT) as short as 10 h. The results from the pilot-scale study also indicate that the selective oxidation of ammonium to nitrite is a reliable process as the accumulation of nitrate was never an issue during a 330-day trial. The SBR process concept was extended to achieve complete nitrogen removal through nitritation and denitritation in the laboratory scale. The experimental results indicate that a total reduction of 96-98% of the ammonium nitrogen from biosolids dewatering liquids (influent concentration typically 1,200 g m(-3)) was achieved with a short HRT of 1.1 d and a removal rate of 1.05 kgNm(-3)d(-1). This process concept was tested at pilot scale where the nitritation process could be started up without temperature control in a short period of time. Nitrogen removal rates up to 1.2 kgNm(-3)d(-1) at an HRT of 0.88 d have been obtained. COD to nitrogen ratios required in the pilot plant were consistently in the range 1.6-1.9 kgCOD kg(-1)N removed.
Lai
E
E
Advanced Wastewater Management Centre, University of Queensland.
Senkpiel
S
S
Solley
D
D
Keller
J
J
D019149:Bioreactors; D002244:Carbon / Q000302:isolation & purification / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D009573:Nitrites / Q000737:chemistry* / Q000378:metabolism; D009584:Nitrogen / Q000302:isolation & purification* / Q000378:metabolism; D010084:Oxidation-Reduction; D010865:Pilot Projects; D000644:Quaternary Ammonium Compounds / Q000302:isolation & purification / Q000378:metabolism; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*; D013997:Time Factors; D014865:Waste Disposal, Fluid / Q000379:methods*
D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D002244:Carbon; D009584:Nitrogen