Modified Stover-Kincannon Model Research Articles

Kinetic analysis of phenol, thiocyanate and ammonia-nitrogen removals in an anaerobic–anoxic–aerobic moving bed bioreactor system

A simulated wastewater containing phenol (2500 mg/L), thiocyanate and ammonia-nitrogen (500 mg/L) was treated in an anaerobic (R1)–anoxic (R2)–aerobic (R3) moving bed biofilm reactor system at different hydraulic retention time (HRT) intervals (total HRT 3–8 days, R1: 1.5–4 days; R2: 0.75–2 days and R3: 0.75–2 days) and feed thiocyanate (SCN −) concentrations (110–600 mg/L) to determine substrate removal kinetics. In R1, phenol and COD reduction and specific methanogenic activity were inhibited due to the increase of SCN − in feed. Bhatia et al. model having inbuilt provision of process inhibition described the kinetics of COD and phenol utilization with maximum utilization rates of 0.398 day −1 and 0.486 day −1, respectively. In R2 and R3 modified Stover–Kincannon model was suitable to describe substrate utilization. In R2 respective maximum SCN −, phenol, COD and NO 3 −-N utilization rates were 0.23, 5.28, 37.7 and 11.82 g/L day, respectively. In aerobic reactor R3, COD, SCN − and NH 4 +-N removal rates were, respectively, 10.53, 1.89, and 2.17 g/L day. The minimum total HRT of three-stage system was recommended as 4 days.

Performance evaluation and kinetic modeling of the start-up of a UASB reactor treating municipal wastewater at low temperature

A kinetic modeling-based study was carried out to evaluate the start-up performance of a 10-L up-flow anaerobic sludge blanket (UASB) reactor treating municipal wastewater under different organic and hydraulic loading conditions. The reactor was operated for 105 days (around 4 months) below 20 °C and with three different hydraulic retention times of 24, 12 and 5 h. Imposed volumetric organic loading rates (OLR) ranged from 0.57 (±0.05) to 11.78 (±0.85) kg TCOD/m(3)-day. Although relatively high incoming volumetric OLR values were employed to the system, the UASB reactor demonstrated a favorable performance on the anaerobic treatability of municipal wastewater, and no process failure was recorded in the start-up stage. On the basis of experimental results, the modified Stover-Kincannon model was successfully applied to define the start-up kinetics with a very high value of the correlation coefficient (R = 0.9729). Maximum substrate utilization rate constant and saturation constant of the modified Stover-Kincannon model were determined as U (max) = 1.996 g/L-day and K (B) = 1.536 g/L-day, respectively.

The kinetics of nitrogen removal and biogas production in an anammox non-woven membrane reactor

The anammox non-woven membrane reactor (ANMR) is a novel reactor configuration to culture the slowly growing anammox bacteria. Different mathematical models were used to study the process kinetics of the nitrogen removal in the ANMR. The kinetics of nitrogen gas production of anammox process was first evaluated in this paper. For substrate removal kinetics, the modified Stover-Kincannon model and the Grau second-order model were more applicable to the ANMR than the first-order model and the Monod model. For nitrogen gas production kinetics, the Van der Meer and Heertjes model was more appropriate than the modified Stover-Kincannon model. Model evaluation was carried out by comparing experimental data with predicted values calculated from suitable models. Both model kinetics study and model testing showed that the Grau second-order model and the Van der Meer and Heertjes model seemed to be the best models to describe the nitrogen removal and nitrogen gas production in the ANMR, respectively.

Performance and kinetic evaluation of anaerobic moving bed biofilm reactor for treating milk permeate from dairy industry

High strength milk permeate derived from ultra-filtration based cheese making process was treated in an anaerobic moving bed biofilm reactor (AMBBR) under mesophilic (35 °C) condition. Total chemical oxygen demand (TCOD) removal efficiencies of 86.3–73.2% were achieved at organic loading rates (OLR) of 2.0–20.0 g TCOD L −1 d −1. A mass balance model gave values of methane yield coefficient ( Y G/S) and cell maintenance coefficient ( k m) of 0.341 L CH 4 g −1 TCOD removed and 0.1808 g TCOD removed g −1 VSS d −1, respectively. The maximum substrate utilization rate U max was determined as 89.3 g TCOD L −1 d −1 by a modified Stover–Kincannon model. Volumetric methane production rates (VMPR) were shown to correlate with the biodegradable TCOD concentration through a Michaelis–Menten type equation. Moreover, based on VMPR and OLR removed from the reactor, the sludge production yield was determined as 0.0794 g VSS g −1 TCOD removed.

Use of the Static Granular Bed Reactor (SGBR) with anaerobic sludge to treat poultry slaughterhouse wastewater and kinetic modeling

Poultry slaughterhouses discharge very high amount of wastewaters and these wastewaters can be treated successfully at a very low cost using anaerobic treatment. In this study, the Static Granular Bed Reactor (SGBR), a newly developed anaerobic process which is fully anaerobic granule, and another Static Granular Bed Reactor containing both anaerobic granular biomass and non-granular biomass were employed for the treatment of poultry slaughterhouse wastewater. The objective of the use of two reactors having different types of anaerobic biomass is to evaluate whether anaerobic sludge could be used effectively instead of anaerobic granule, which is much more difficult to obtain than the other during the start up period. Average COD removal efficiencies were greater than 95% for both of the reactors. Furthermore, Grau second-order and modified Stover–Kincannon models were successfully used to develop a kinetic model of the experimental data with a high correlation coefficient ( R 2 > 0.95).

Performance of an anaerobic bioreactor with biomass recycling, continuously removing COD and sulphate from industrial wastes

A 30-l anaerobic bioreactor with biomass recycling was used to provide a continuous reduction in sulphate and a continuous COD removal from wastewater, which consisted of the effluent from an industrial pig fattening farm, enriched with technical FeSO(4) x 7H(2)O, a waste product from ferrous metallurgy. The concentrations of sulphate and COD in the wastewater amounted to 2.73 g l(-1) and 3.15 g l(-1), respectively. The HRT (hydraulic retention time) of 10-1.7d produced an extent of sulphate and COD reduction which totalled 98% and 88%, respectively. When the HRT was further shortened, the efficiency of reduction in sulphate and COD decreased. The maximum removal rate constants for both the pollutants, calculated by means of a modified Stover-Kincannon model, were 80.9 g COD l(-1)d(-1) and 41.8 g SO(4)(2-)l(-1)d(-1), the values of the saturation constants being 91.582 g COD l(-1)d(-1) and 42.398 g SO(4)(2-)l(-1)d(-1).

Determination of kinetic constants of hybrid textile wastewater treatment system

The present study is related to treatment of textile wastewater in microaerophilic–aerobic hybrid reactor. The study showed the effectiveness of biological treatment of wastewater involving appropriate microorganism and suitable reactors. COD and color were reduced to 82–94%, and 99% respectively for textile wastewater. The reactor was operated at highest loading of 16.4 g COD g l −1 d −1 and obtained 80% COD and 72% color removal. Biokinetic models were applied to data obtained from experimental studies in continuously operated hybrid reactor. Treatment efficiencies of the reactor were investigated at different hydraulic retention times (2.3–9.1 d) and organic loading rates (2.6–16.4 g COD l −1 d −1). Second-order and a Stover–Kincannon models were best fitted to the hybrid column reactor. The second-order substrate removal rate constant ( k 2(S)) was found as 41.44 d −1 for hybrid reactor. Applying the modified Stover–Kincannon model to the hybrid reactor, the maximum removal rate constant ( U max) and saturation value constant ( K B) were found to be 212 g l −1 d −1 and 22.89 g l −1 d −1, respectively.

Kinetic of carbonaceous substrate in an upflow anaerobic sludge sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP)

The performance of an upflow anaerobic sludge blanket (UASB) reactor treating 2,4 dichlorophenol (2,4 DCP) was evaluated at different hydraulic retention times (HRTs) using synthetic wastewater in order to obtain the growth substrate (glucose-COD) and 2,4 DCP removal kinetics. Treatment efficiencies of the UASB reactor were investigated at different hydraulic retention times (2–20 h) corresponding to a food to mass ( F/ M) ratio of 1.2–1.92 g-COD g −1 VSS day −1. A total of 65–83% COD removal efficiencies were obtained at HRTs of 2–20 h. In all, 83% and 99% 2,4 DCP removals were achieved at the same HRTs in the UASB reactor. Conventional Monod, Grau Second-order and Modified Stover–Kincannon models were applied to determine the substrate removal kinetics of the UASB reactor. The experimental data obtained from the kinetic models showed that the Monod kinetic model is more appropriate for correlating the substrate removals compared to the other models for the UASB reactor. The maximum specific substrate utilization rate ( k) (mg-COD mg −1 SS day −1), half-velocity concentration ( K s) (mg COD l −1), growth yield coefficient ( Y) (mg mg −1) and bacterial decay coefficient ( b) (day −1) were 0.954 mg-COD mg −1 SS day −1, 560.29 mg-COD l −1, 0.78 mg-SS g −1-COD, 0.093 day −1 in the Conventional Monod kinetic model. The second-order kinetic coefficient ( k 2) was calculated as 0.26 day −1 in the Grau reaction kinetic model. The maximum COD removal rate constant ( U max) and saturation value ( K B) were calculated as 7.502 mg COD l −1 day −1 and 34.56 mg l −1 day −1 in the Modified Stover–Kincannon Model. The ( k)(mg-2,4 DCP mg −1 SS day −1), ( K s) (mg 2,4 DCP l −1), ( Y) (mg SS mg −1 2,4 DCP) and ( k d) (day −1) were 0.0041 mg-2,4 DCP mg −1 SS day −1, 2.06 mg-COD l −1, 0.0017 mg-SS mg −1 2,4 DCP and 3.1×10 −5 day −1 in the Conventional Monod kinetic model for 2,4 DCP degradation. The second-order kinetic coefficient ( k 2) was calculated as 0.30 day −1 in the Grau reaction kinetic model. The maximum 2,4 DCP removal rate constant ( U max) and saturation value ( K B) were calculated as 0.01 mg COD l −1 day −1 and 9.8×10 −3 mg l −1 day −1 in the Modified Stover–Kincannon model.

Anaerobic treatment of saline wastewater by Halanaerobium lacusrosei

An upflow anaerobic packed bed reactor was operated continuously with synthetic saline wastewater at different initial COD concentrations (COD 0 = 1900–6300 mg/L), salt concentrations (0–5%, w/v) and hydraulic retention times ( θ H = 11–30 h) to investigate the effect of those operating parameters on COD removal from saline synthetic wastewater. Anaerobic salt tolerant bacteria, Halanaerobium lacusrosei, were used as dominant microbial culture in the process. The percent COD removal reached up to 94% at COD 0 = 1900 mg/L, 19 h hydraulic retention time and 3% salt concentration. No substrate inhibition effect was observed at high feed CODs. Increasing hydraulic retention time from 11 h to 30 h resulted in a substantial improvement in the COD removal from 60% to 84% at around COD 0 = 3400 mg/L and 3% salt concentration. Salt inhibition effect on COD utilization was observed at above 3% salt concentration. Modified Stover–Kincannon model was applied to the experimental data to determine the biokinetic coefficients. Saturation value constant, and maximum utilization rate constant of Stover–Kincannon model for COD were determined as K B = 5.3 g/L day, U max = 7.05 g/L day, respectively.

Kinetic analysis of treatment of textile wastewater in hybrid column upflow anaerobic fixed bed reactor

Abstract Treatment of textile wastewater is considered to be difficult by traditional systems. The present study is related to treatment of textile wastewater in an anaerobic reactor. The study showed the effectiveness of biological treatment of wastewater involving appropriate microorganism and suitable support media in a hybrid column, upflow anaerobic fixed bed (UAFB) reactor. COD and color were reduced to 84.80%, and 90% for textile wastewater. The reactor was operated at 1.038–8.21 g COD m −3 d −1 of loading and found that 81.58% COD and 86.22% color removal at the highest loading rate. At steady state under anaerobic condition, color was effectively removed. Biokinetic models were applied to data obtained from experimental studies in UAFB reactor. Treatment efficiencies of the reactor were investigated at different hydraulic retention times (9.6–23.76 h) and organic loading rates (1.038–8.21 g COD m −3 d −1 ). Second-order and a Stover–Kincannon models were best fitted to the hybrid column reactor. The second-order substrate removal rate constant ( k 2(S) ) was found as 10.50 h −1 for UAFB. Applying the modified Stover–Kincannon model to the UAFB reactor, the maximum removal rate constant ( U max ) and saturation value constant ( K B ) were found to be 31.69 and 45.37 g d −1 , respectively.

Kinetic analysis of dyestuff and COD removal from synthetic wastewater in an anaerobic packed column reactor

An anaerobic packed column reactor was operated continuously at different dyestuff loading rates, (0.05–0.4 g/(l day)) and COD loading rates (1–8 g/(l day)) in order to determine dyestuff and COD removal kinetic constants. The system was operated at room temperature (20 ± 1 °C) and at pH 7 using an immobilized anaerobic bacterial consortium called PDW. Synthetic wastewater containing textile dyestuff Reactive Red 195 was fed from the bottom of the reactor. Around 90% decolourization efficiency was obtained for dyestuff loading rates up to 0.15 g/(l day). COD removal efficiency was obtained between 5 and 35% for the applied loads. Modified Stover–Kincannon model was applied to the experimental data. Saturation value constant and maximum utilization rate constant of Stover–Kincannon model for dyestuff and COD were determined as K B = 17.8 g/(l day), U max = 19.5 g/(l day) and K B = 37.9 g COD/(l day), U max = 12.9 g COD/(l day), respectively. The predicted effluent dyestuff and COD concentrations were calculated using the constants and it was found that they are in good agreement with the observed ones.

Determination of kinetic constants of an anaerobic hybrid reactor

By applying some biokinetic models to data obtained from experimental studies carried out on a laboratory scale anaerobic hybrid model reactor, determination of some kinetic constants of the reactor was aimed. Treatment efficiencies of the model reactor were investigated at different hydraulic retention times (0.5, 1, and 2 days) and organic loading rates (1–10 kgCOD/m 3*d). Most suitable models were determined and kinetic parameters were calculated depending on the operational conditions. As a result of the calculations, second-order model and a Stover–Kincannon model were found to be the most appropriate models for the hybrid reactor. The second order substrate removal rate constant ( k 2(S)) was found as 2.32, 2.57, and 10.81 per day for sludge bed region, fixed bed region, and overall reactor, respectively. Applying the modified Stover–Kincannon model to the fixed bed region of the reactor, the maximum removal rate constant ( U max) and saturation value constant ( K B) were found to be 83.3 and 186.23 g l per day, respectively.

Kinetic analyses of the operation of mesophilic and thermophilic anaerobic filters treating a simulated starch wastewater

Two anaerobic filters, one mesophilic and one thermophilic, were operated with a starch-based feed at a series of organic loading rates. The results were analysed in two ways, with a modified Stover–Kincannon model and an empirical model based on the influent COD and the hydraulic retention time. Both models were applicable to both filters and the Stover–Kincannon model showed that the thermophilic filter had a maximum COD utilisation rate almost 15 times greater than the mesophilic filter. The Stover–Kincannon model was further modified to describe the methane yield. There was essentially, no difference in the maximum specific methane yields from the two filters. The results of analysing the experimental data with the empirical model showed that, although the model described the performance of both filters well, the value of the predicted final effluent COD was very sensitive to the value of the exponent associated with the influent COD.

Kinetic analysis of an anaerobic filter treating soybean wastewater

An investigation into the kinetics of the treatment of soybean wastewater in an anaerobic filter is described. The substrate loading removal rate was compared with predictions from a modified Stover–Kincannon model, the Monod model and a regression relationship. The modified Stover–Kincannon model produced the best fit with the experimental results. The modified Stover–Kincannon model could also be used to determine the reactor volume required to decrease a set influent organic concentration to a given effluent concentration, or to determine the effluent substrate concentration for a given volume of an anaerobic filter and influent organic concentration. The overall reaction order in the anaerobic filter treating soybean wastewater appeared to be close to half order. The methane production kinetics could be described by a similar relationship that used to describe the organic substrate removal kinetics of the anaerobic filter treating soybean wastewater. The kinetic relationships derived from the lab-scale experiment provided good estimates of the performance of pilot- and full-scale anaerobic filters packed with the same media and treating the same wastewater in terms of the effluent chemical oxygen demand (COD) concentrations and the specific methane production rates.