N₂O Production during Nitrogen Removal via Nitrite from Domestic Wastewater: Main Sources and Control Method

Abstract

Nitrite has been commonly recognized as an important factor causing N(2)O production, which weakened the advantages of nitrogen removal via nitrite. To reduce and control N(2)O production from wastewater treatment plants, both long-term and batch tests were carried out to investigate main sources and pathways of N(2)O production during nitrogen removal via nitrite from real domestic wastewater. The obtained results showed that N(2)O production during nitrogen removal via nitrite was 1.5 times as much as that during nitrogen removal via nitrate. It was further demonstrated that ammonia oxidization were main source of N(2)O production during nitrogen removal from domestic wastewater; whereas, almost no N(2)O was produced during nitrite oxidization and anoxic denitrification. N(2)O production during nitrogen removal via nitrite decreased about 50% by applying the step-feed SBR, due to the effective control of nitrite and ammonia, the precursors of N(2)O production. Therefore, the step-feed system is recommended as an effective method to reduce N(2)O production during nitrogen removal via nitrite from domestic wastewater.

Nitrous oxide emissions in a membrane bioreactor treating saline wastewater contaminated by hydrocarbons

“…The N 2 O-N flux trend reflected the same pattern of the N 2 O-N concentration from day 35 to day 75. It is worth noting that the flux emitted from the aerated tanks was 1-2 order of magnitude higher than that emitted from the anoxic one (Yang et al, 2009;Daelman et al, 2012;Law et al, 2012b).…”

“…Additionally, increased N 2 O production during AOB denitrification has been observed to have a strong correlation with NO 2 accumulation under either anoxic or aerobic conditions (Kampschreur et al, 2009;Yang et al, 2009;Yu et al, 2010).…”

“…A higher N 2 O production has been observed, for instance, when performing biological treatment using synthetic rather than real wastewater. Indeed, it was hypothesized that this result was related to the lower biomass diversity when operating with synthetic wastewater (Yang et al, 2009).…”

Source identification of nitrous oxide on autotrophic partial nitrification in a granular sludge reactor

“…N 2 O production pathways have also been investigated with the use of mathematical models (Ni et al, 2013;Law et al, 2012) and by addition of substrates (NH 2 OH or NO 2 -) (Wunderlin et al, 2012;Yang et al, 2009). In contrast to this method, isotopomer analysis can reveal the N 2 O production pathways directly and quantitatively with high reliability.…”

“…In contrast, there are few studies on N 2 O production pathways. Nitrifier denitrification was the key biological pathway of N 2 O production in an intermittently aerated sequencing batch biofilm reactor for PN treating synthetic ammonium-rich wastewater (Kong et al, 2013b) while NH 2 OH oxidation pathway was the main source of N 2 O in a sequencing batch reactor (SBR) for PN (PN-SBR) (Law et al, 2011;Yang et al, 2009). To determine 5 which pathway is responsible for N 2 O production in a wastewater treatment process is still challenging, because a variety of operational parameters (concentrations and loading rates of nitrogenous compounds, dissolved oxygen (DO) and organic carbon, pH, a ratio of organic carbon and nitrogenous compounds (COD/N) and temperature) influence N 2 O production in a PN process (Tallec et al, 2006;Kampschreur et al, 2009b;Desloover et al, 2012;Wunderlin et al, 2012;Law et al, 2011).…”