Comparison of overall performance between moving-bed and conventional sequencing batch reactor

The main objective of present work was to compare the overall performances of [moving-bed] and [conventional] sequencing batch reactor. For this purpose, different experimental parameters including COD and dye concentration, turbidity, MLSS concentration, MLVSS/MLSS ratio, sludge volume index [SVI] and Oxidation-Reduction Potential [ORP] were calculated. One conventional sequencing batch reactor and three moving-bed sequencing batch reactors [MB-SBR] were operated in this study. Each MB-SBR was equipped with a type of moving biofilm carrier. The results of dye, COD and turbidity analysis showed that there were no significant differences between the moving-bed and conventional sequencing batch reactors in the matters of effluent quality. A higher fluctuation of MLSS concentration and also higher SVI were observed in moving-bed compared to that of the conventional sequencing batch reactor. Higher ORP values which mean higher oxidation potential were measured in the reactors equipped with the moving carriers in comparison with those measured in the conventional sequencing batch reactor

comparison between aluminum and iron electrodes on removal of phosphate from aqueous solutions by electrocoagulation process

This study presents a comparison between aluminum and iron plate electrodes on phosphate removal from aqueous solutions by electrocoagulation process. The effectiveness of main operational parameters such as initial pH, initial phosphate concentration and current density were examined. In addition, treated solution and sludge characteristics, energy consumption and electrode mass depletion were compared for both electrodes. All experiments were done in an electrocoagulation cell with effective volume of 2 liters. It was found that the aluminum electrode has higher removal efficiency compared to the iron electrode in the same operational conditions. Phosphate removal efficiencies of 100% and 84.7% were observed for aluminum and iron electrode in a special case with optimum initial pH, maximum current density and maximum initial phosphate concentration equal to 3, 250 A/m[2], 400mg/l PO[4][-3], respectively. Furthermore, less treated solution turbidity, higher secondary pollution [remained Al] and less electrode mass depletion was observed for the aluminum electrode

Decolorization of an acidic dye from synthetic wastewater by sludge of water treatment plant

In this research, sludge of Jalaliyeh water treatment plant in Tehran was used as an alternative coagulant for the removal of a specific type of acid dye [acid red 119 [AR119]]. For this purpose, the effect of initial pH, coagulant dose and initial dye concentration on dye removal efficiency were investigated. Results showed that the dye removal rates were largely dependent on pH. When the solution pH was increased from 3 to 8, the dye removal rates decreased from 96.3% to 2.3%. The removal efficiencies of the dye using 130-350 mg dried sludge/L were more than 90% at initial pH =3. With the increase of initial dye concentration in the range of 10-200 mg/L, the removal efficiency increased at first [from 10-40 mg/L] and then declined. So, sludge of Jalaliyeh water treatment plant may be considered as an appropriate coagulant for the removal of AR119 dye

Removal of reactive blue 19 by adding polyaluminum chloride to sequencing batch reactor system

The main objective of this study was to evaluate Reactive Blue 19 dye removal efficiency in aerobic sequencing batch reactor [SBR] process by adding polyaluminum chloride [PAC1]. PAC1 was added to the reactors in concentrations of 0, 1, 5, 15 and 30 mg-Al/L [SBR[1] to SBR[5]] after filling periods. Initial dye concentrations were selected to be 40 mg/L for all reactors. The averages of dye removal efficiencies were more than 57% in all reactors. The maximum and minimum dye removal efficiencies were 71.7% +/- 13.6 and 57.7% +/- 34.3 in SBR3 and SBR4, respectively. According to the obtained results, PAC1 had not any significant effects on the COD removal efficiency. The MLSS and MLVSS concentration of SBRs had an increasing rate during whole operation time and reached from 2500 mg/L [1[st] day] to 4900 mg/L [39[th] day]. The maximum increasing rate was 50% in SBR[5]

Effect of dye concentration on sequencing batch reactor performance

Reactive dyes have been identified as problematic compounds in textile industries wastewater as they are water soluble and cannot be easily removed by conventional aerobic biological treatment systems. The treatability of a reactive dye [Brill Blue KN-R] by sequencing batch reactor and the influence of the dye concentration on system performance were investigated in this study. Brill Blue KN-R is one of the main dyes that are used in textile industries in Iran. Four cylindrical Plexiglas reactors were run for 36 days [5 days for acclimatization of sludge and 31 days for normal operation] at different initial dye concentrations. The dye concentrations were adjusted to be 20, 25, 30 and 40 mg/L in the reactors R1, R2, R3 and R4, respectively. In all reactors, effective volume, influent wastewater flowrate and sludge retention time were 5.5 L, 3.0 L/d and 10 d, respectively. According to the obtained data, average dye removal efficiencies of R1, R2, R3 and R4 were 57% +/- 2, 50.18% +/- 3, 44.97% +/- 3 and 30.98% +/- 3, respectively. The average COD removal efficiencies of all reactors were 97% +/- 1, 97.12% +/- 1, 96.93% +/- 1 and 97.22% +/- 1, respectively. The dye removal efficiency was decreased by increasing the dye concentration with the correlation coefficient of 0.997

Effect of sludge retention time on treating high load synthetic wastewater using aerobic equencing batch reactors

The main aim of this study was to investigate the effect of sludge retention time on performance of aerobic synthetic batch reactor for treating a high load milk synthetic wastewater. For this purpose, four lab-scale sequencing batch reactors were operated under aerobic conditions with the same conditions at different sludge retention times [SRTs], feeding by high load milk synthetic wastewater. Operating volume, influent flow rate and influent organic loading rate for all reactors were adjusted to 5.5 L, 3.5 L/d and 1400 gCOD/m3d, respectively. The average effluent COD for reactor 1 to 4 with SRT of 5, 10, 15 and 20 d were 108, 97, 91 and 84 mg/L, respectively. COD removal was 94.99, 95.43, 95.86 and 96.16 percent respectively and slightly changed with SRT. However, the overall trend of COD removal vs. SRT showed an increasing rate with the correlation factor [R2] of 0.99. Reactor 2 with SRT of 10 d[SVI] had the maximum effluent TSSave [34mg/L] and turbidityave [5.89 mg/L] and the minimum sludge volume index [41mL/g]. All reactors had SVIave of lower than 75 mL/g and effluent turbidityave less than 6 NTU which was lower than Iranian national discharge standards [<50 NTU]. SRT had directly influenced the biomass concentration, as the MLSSave of reactor 1 to 4 were found to be 1824, 2694, 3210 and 3864 mg/L respectively. Best performance [minimum effluent COD, TSS and turbidity] was occurred in reactor 4 with SRT of 20 d