Studies on nitrification of aniline with acclimated activated sludge

Abstract

Aniline, a toxic, organic pollutant, occurs in a number of industrial effluents. Apart from carbonaceous oxygen demand, aniline imposes a nitrogenous oxygen demand, due to its nitrogen content, in excess of that required for cell growth. Incomplete biodegradation will result in ammonia production; this also exerts toxicity. Hence, nitrification of aniline should be ensured in the biological treatment before discharge into receiving streams. Aniline, however, is reported to inhibit the nitrification process. Aniline degradation was studied in laboratory continuous activated sludge with an acclimated culture developed in synthetic feed to determine the extent of complete biological degradation. Aniline-N (even at 400 mg/L aniline concentration)could be converted to nitrate-N with ammonium-N and nitrite-N formed as intermediates at a detention time of 24 h. The nitrification, however, was suppressed by aniline. The degradation of aniline to ammonia releases the suppression and the nitrification proceeds rapidly.

Metagenomics and Metatranscriptomics Suggest Pathways of 3-Chloroaniline Degradation in Wastewater Reactors

“…Ma et al (2020) reported full nitrification recovery within 12 days of a pulse 3-CA input (at lower concentrations) in a single-reactor study, possibly concurrent with the washout of 3-CA from the reactor. Kelly et al (2004) reported a 17-day recovery period for total nitrification after a 1-chloro-2,4-dinitrobenzene pulse addition at a comparable concentration. The resumption of partial nitrification in our study may be attributed to the long SRT of 30 days.…”

“…Major shifts in process performance can occur when a disturbance is imposed on a community (Allison and Martiny, 2008) and can impact a wastewater treatment plant’s treatment capability over the long-term (Vuono et al, 2015). Such disturbances may be operational (Thompson, 2006; Valipour et al 2014, Santillan et al, 2020), physical (Hwang et al, 2006; Vargas et al, 2013), or chemical (Kelly et al, 2004; Falk and Wuertz, 2010). While short-term (pulse) disturbances have been studied extensively (Boon et al, 2000; Henriques et al, 2007; Ma et al, 2020), long-term (sustained) disturbances have not.…”

Modeling of Nitrification Inhibition with Aniline in Suspended‐Growth Processes

“…Synthetic wastewater containing aniline and inorganic salts was used for the experiment. A stock solution based on the composition in Table 1 was prepared to provide a C/P ratio of 100:2, which is generally recommended for activated sludge (Kumar et al, 1984). Aniline was used as the sole carbon source for the experiment.…”