Anaerobic rotating disc batch reactor nutrient removal process enhanced by volatile fatty acid addition

Abstract

RBC effluent needs further treatment because of water-quality standards requiring low nitrogen and phosphorus concentrations. It may be achieved by using reactors with biomass immobilized on the filling's surface as post-denitrification biofilm reactors. Due to the lack of organic matter in treated wastewater, the introduction of external carbon sources becomes necessary. The new attached growth bioreactor--anaerobic rotating disc batch reactor (ARDBR)--was examined as a post-denitrification reactor. The impact of selected volatile fatty acids on nutrient removal efficiency in an ARDBR was studied. The biofilm was developing on totally submerged discs mounted coaxially on a vertical shaft. Acetic, propionic, butyric and caproic acids were applied. Wastewaters were removed from the reactors after 24-h treatment, together with the excess solids. In the ARDBR tank, there was no biomass in the suspended form at the beginning of the treatment process. Acids with a higher number of carbon atoms (butyric and caproic) were the most efficient in denitrification process. The highest phosphorus removal efficiency was noted in the ARDBR with butyric and propionic acids. The lowest unitary consumption of the external source of carbon in denitrification was recorded for acetic acid, whereas the highest one for caproic acid.

The Kinetics of Pollutant Removal through Biofiltration from Stormwater Containing Airport De-Icing Agents

“…The activity of heterotrophic denitrifying bacteria is less dependent on the temperature than that of nitrifying bacteria [27]. Kadlec and Reddy [28] reported that 20-35 • C was the optimal temperature range for denitrification, which slows down considerably at temperatures lower than 10 • C and greater than 30 • C. Champagne et al [29] noted that providing a source of readily biodegradable organic carbon helped maintain high nitrification efficiencies even at temperatures under 10 • C. In the present study, the denitrification rate increased at higher temperatures and decreased at higher C/N ratios (Figure 2; Supplementary Figures S4-S6), even though the presence of a readily available source of organic carbon is one of the main drivers of effective denitrification [30,31] . Lowering the biofilter operating temperature to 0 • C reduced the performance by 36.7% and 40.0% against the control, respectively.…”

“…Champagne et al [29] noted that providing a source of readily biodegradable organic carbon helped maintain high nitrification efficiencies even at temperatures under 10 °C . In the present study, the denitrification rate increased at higher temperatures and decreased at higher C/N ratios (Figure 2; Supplementary Figures S4-S6), even though the presence of a readily available source of organic carbon is one of the main drivers of effective denitrification [30,31]. In series 1 (C/N = 0.5), oxidized nitrogen was reduced in the control reactor (T = 25 °C ) at a rate of 0.31 mgN/L•h.…”

Energy Consumption for Nutrient Removal from High-Nitrate and High-Phosphorus Wastewater in Aerobic and Anaerobic Bioelectrochemical Reactors

“…The research was carried out in two stages using research models of two BERs, REBDC and SBBR, under laboratory conditions, at a temperature of about 20.0 ± 1 • C. In both reactors, sodium acetate was added to wastewater as a source of carbon to ensure the growth of the biofilm biomass [27,40]. The results of the first stage served to limit the scope of the second one with regard to the current density and the hydraulic retention time.…”

Archives of Environmental Protection

“…Sodium acetate was added to wastewater as a source of carbon in part II of the study to provide appropriate conditions for biofilm development. This allowed for obtaining the C: N ratio of 0.5, which promotes the development of heterotrophic biofilm organisms and, at the same time, does not impair autotrophic denitrification (Rodziewicz et al, 2015) the introduction of external carbon sources becomes necessary. Wastewater characteristic is presented in Table 1.…”