Non-Invasive Monitoring for Early Warning Nitrification Failure

Butler, Mark; Cartmell, Elise; Stokes, L.; Stephenson, Tom

doi:10.2175/193864705783858837

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Likewise, a previous study has also observed that the N 2 O concentration increased when an ATU dose of 0.076 mg.L -1 was applied to the aeration tank (Burgess et al, 2002b). At full-scale, the off-gases can be captured via a hood before delivery to the N 2 O detection system; this has been demonstrated on full-scale industrial and municipal activated sludge plants (Butler et al, 2005b).…”

Section: Discussionmentioning

confidence: 99%

Nitrous oxide emissions for early warning of biological nitrification failure in activated sludge

et al. 2009

View full text Add to dashboard Cite

Experiments were carried out to establish whether nitrous oxide (N2O) could be used as a non-invasive early warning indicator for nitrification failure. Eight experiments were undertaken; duplicate shocks DO depletion, influent ammonia increases, allylthiourea (ATU) shocks and sodium azide (NaN3) shocks were conducted on a pilot-scale activated sludge plant which consisted of a 315 L completely mixed aeration tank and 100 L clarifier. The process performed well during pre-shock stable operation; ammonia removals were up to 97.8% and N2O emissions were of low variability (<0.5 ppm). However, toxic shock loads produced an N2O response of a rise in off-gas concentrations ranging from 16.5 to 186.3 ppm, followed by a lag-time ranging from 3 to 5 h ((0.43-0.71) x HRT) of increased NH3-N and/or NO2(-) in the effluent ranging from 3.4 to 41.2 mg L(-1). It is this lag-time that provides the early warning for process failure, thus mitigating action can be taken to avoid nitrogen contamination of receiving waters.

show abstract

Section: Discussionmentioning

confidence: 99%