Experimental sulphide inhibition calibration method in nitrification processes: A case-study

• Published in: Journal of environmental management 2020-11, Vol.274, p.111191-111191, Article 111191
• Main Authors: Noriega-Hevia, G., Mateo, O., Maciá, A., Lardín, C., Pastor, L., Serralta, J., Bouzas, A.
• Format: Article
• Language: English
• Subjects: Ammonia-oxidising bacteria calibration; Calibration methodology; Nitrification inhibition; Nitrite-oxidising bacteria calibration; Sulphide inhibition
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.111191

Sulphide is one of the inhibitors in the nitrification process in WWTP in regions with sulphate rich soils. As little information is currently available on sulphide nitrification inhibition, the aim of this study was to develop a method based on a modification of the Successive Additions Method to calibrate the effect of sulphide on the activity of ammonia-oxidising bacteria (AOB) and nitrite-oxidising bacteria (NOB). The developed method was then applied to activated sludge samples from two WWTPs with different influent sulphide concentrations. In both cases, sulphide had a greater inhibitory effect on NOB than AOB activity. The sulphide inhibition was found to be lower in the activated sludge fed with sulphide-rich wastewater. The AOB and NOB activity measured at different sulphide concentrations could be accurately modelled with the Hill inhibition equation. •The methodology proposed is able to calibrate nitrification inhibition by sulphide.•The sulphide inhibition is reduced by sludge acclimation.•The sulphide inhibitory effect is higher in NOB than in AOB.