Calibration of model for the utilization rate of organic and nitrogenated substrates by the microorganism in a sequencing batch reactor

Abstract

This paper deals with the calibration of the model for the utilization rate of organic and nitrogenated substrates (URONS) by the microorganisms in a sequencing batch reactor. The URONS model parameterization was carried out using data obtained from two experimental designs (EDs) applied on tannery wastewater (TW), which included as factors: First ED (aeration sequence and cycle duration) reached a COD removal efficiency (RE) between 29% (cycle duration of 6 h) and 48% (cycle duration of 24 h).Second ED (aeration sequence and filling time) obtained COD-RE (47-51%), NH 4 -N-RE (71-91%), and TKN-RE (50-67%). The URONS model was based on Monod's equation modification. For the first ED, the results of the maximum URONS parameter (r sm ) of 135-946 mg/L⋅h suggest the organic substrate accumulation due to a possible inhibition of the microorganisms by TW substances such as heavy metals and metal halides. For the second ED, the r sm parameter values resulted negative and varying in the order of −10 −2 to −10 −4 mg/L⋅h with respect to (r sm ) for the first ED indicating that a better microorganism performance for URONS occurred in the second ED. For both EDs, the saturation parameter (K s ) values compared to the effluent substrate concentration suggest that the primary substrate for biodegradation was present in the TW.

An approach to remediation of a tropical aquifer contaminated with hydrocarbons

“…The SBR obtained an efficiency of 97% in the removal of synthetic petroleum wastewater, operating for HRT of 6, 18, and 24 h, with air stripping making a small contribution to overall removal (Shariati et al., 2011). In the current design, the COD removal efficiency was set in 60%, being higher than that found for SBR removing COD associated to tannery wastewater (45%–48%), containing inhibitory and recalcitrant substrates (Exhibit 4) (Freytez et al., 2019a, 2019b, 2019c, 2019d, 2021). The estimated kinetic parameters for the modified Monod equation involved a substrate utilization rate that resulted in 92.2 mg/L/h and the saturation‐inhibition coefficient of 11462.2 mg/L (Exhibit 5).…”

“…The positive values of the microbial kinetic parameter a (utilization coefficient of organic substrates) are a consequence of the effects of recalcitrant and inhibitory substances contained in wastewater such as heavy metals (total chromium) and metal halides (chloride). With another data group, it was found a substrate utilization rate suggesting that the biodegradation occurred in a magnitude of −135.65 mg COD/L.h for T1, and −159 mg COD/L.h for T2 (Freytez Boggio et al., 2021, Freytez & Márquez, 2021). Freytez et al.…”

“…Two EDs were developed with factorial arrangements of 2 2 and 3 × 4 (Freytez et al., 2019a, 2019b, 2019c, 2019d, 2021). Wastewater of a tannery located in Barquisimeto‐Carora Lara, Venezuela was used as the substrate.…”

“…The details about ED can be found in Freytez et al. (2019a, 2019b, 2019c, 2019d, 2021). The first ED (ED‐1) involved two experimental factors; each one was configured in two levels, the cycle duration (6 and 24 h) and the aeration sequences (oxic and anaerobic‐oxic).…”

“…Due to most of the hydrocarbon pollution has reached the vadose zone soil (unsaturated zone) and less in the saturated zone (below the water table), it is feasible to evaluate the application of two options for bioremediation supported in ex situ and in situ techniques. The former is made configuring two coupled reactors in an arrangement integrated by two bioreactors, SS‐SBR followed by a UAF‐3SS, which have been experimentally tested to treat industrial wastewater (Freytez et al., 2019a, 2019b, 2019c, 2019d, 2021) and landfill leachates (Maldonado‐Maldonado et al., 2018a, 2018b, 2020, 2021; Márquez et al., 2020), respectively. For the groundwater treatment, the SS‐SBR might operate as the traditional SBR.…”