Thermophilic treatment by anaerobic granular sludge as an effective approach to accelerate the electron transfer and improve the reductive decolorization of azo dyes in bioreactors

2005 ◽  
Vol 52 (1-2) ◽  
pp. 363-369 ◽  
Author(s):  
A.B. dos Santos ◽  
J. Traverse ◽  
F.J. Cervantes ◽  
J.B. van Lier
Keyword(s):  
Electron Transfer ◽  
Hydraulic Retention Time ◽  
Granular Sludge ◽  
Textile Wastewater ◽  
Anaerobic Treatment ◽  
Significant Difference ◽  
Dye Reduction ◽  
Effects Of Temperature ◽  
Reductive Decolorization ◽  
Electron Transfer Capacity

The effects of temperature, hydraulic retention time (HRT), and the redox mediator, anthraquinone-2,6-disulfonate (AQDS), on electron transfer and subsequent reductive decolorization of dyes from textile wastewater was assessed in mesophilic and thermophilic anaerobic bioreactors. The results clearly show that compared to mesophilic anaerobic treatment, thermophilic treatment at 55 °C is an effective approach for increasing the electron transfer capacity in bioreactors, and thus improving the decolorization rates. At an HRT of 2.5 h and in the absence of AQDS, the color removal was 5.3-fold higher at 55 °C compared to 30 °C. Furthermore, similar decolorizations were found at 55 °C between the AQDS-free and AQDS-supplemented reactors, whereas a significant difference (up to 3.6-fold) on dye reduction occurred at 30 °C.

The effect of hydraulic retention time on granular sludge biomass in treating textile wastewater

2011 ◽  
Vol 45 (16) ◽  
pp. 4711-4721 ◽  
Author(s):  
Khalida Muda ◽  
Azmi Aris ◽  
Mohd Razman Salim ◽  
Zaharah Ibrahim ◽  
Mark C.M. van Loosdrecht ◽  
...  
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Granular Sludge ◽  
Textile Wastewater

Anaerobic Treatment of Slaughterhouse Wastewater in an Expanded Granular Sludge Bed (EGSB) Reactor

1999 ◽  
Vol 40 (8) ◽  
pp. 99-106 ◽  
Author(s):  
L. A. Núñez ◽  
B. Martínez
Keyword(s):  
Suspended Solids ◽  
Hydraulic Retention Time ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Slaughterhouse Wastewater ◽  
Methanogenic Activity ◽  
Loading Rates ◽  
Feasible Option ◽  
One Year ◽  
Sludge Activity

The performance of an Expanded Granular Sludge Bed (EGSB) reactor for treating slaughterhouse wastewater under mesophilic conditions (35°C), was investigated. The reactor was inoculated with granular sludge from an anaerobic reactor of a brewery factory. The averaged COD removal percentages were 67% for total organic loading rates (BV.TCOD) up to 15 kg COD m−3 d−1 and a hydraulic retention time (HRT) of 5 h. Total suspended solids (TSS) were 90% removed for total solids loads of 6 kg TSS m−3 d−1. Fats were 85% removed and no accumulation of fats on the sludge was observed. The specific methanogenic activity of the sludge, after 140 days, was about three times higher than the sludge inoculated into the reactor. The sludge activity did not significantly change after one year of work. These findings indicate that the anaerobic treatment of slaughterhouse wastewater in an EGSB system appears to be a feasible option.

Enhanced Treatment of CSTR Anaerobic Digested Effluent from Poultry Wastewater by IC Reactor

2012 ◽  
Vol 433-440 ◽  
pp. 1239-1244
Author(s):  
Zhan Guang Liu ◽  
Xue Fei Zhou ◽  
Ya Lei Zhang ◽  
Hong Guang Zhu
Keyword(s):  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Controlling Factors ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Internal Circulation ◽  
Poultry Wastewater

The feasibility of applying internal circulation (IC) reactor anaerobic treatment for effluent from a CSTR plant treating poultry wastewater was examined and the key controlling factors were explored. A continuous-flow IC reactor of 12.3L capacity inoculated with anaerobic granular sludge was operated for 98 days at 35±1°C. With corresponding organic loading rate of 1.5-3.5 kgCOD/m3•d at hydraulic retention time of 1.5d, the maximum volumetric biogas production rate of 1.2 m3/m3•d and tCOD (total COD) removal efficiency in the range of 70-80% was achieved. Therefore, IC reactor is competent to treat CSTR effluent from poultry wastewater. The decrease of sCOD (soluble COD) relative to tCOD and ammonia inhibition may lead to deterioration of IC reactor anaerobic treatment.

Riboflavin as a redox mediator accelerating the reduction of the azo dye Mordant Yellow 10 by anaerobic granular sludge

2003 ◽  
Vol 48 (6) ◽  
pp. 187-193 ◽  
Author(s):  
J.A. Field ◽  
J. Brady
Keyword(s):  
Textile Industry ◽  
Azo Dye ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Redox Mediator ◽  
Maximum Increase ◽  
Zero Order Kinetics ◽  
Redox Active ◽  
Dye Reduction ◽  
Enzyme Cofactors

Azo dyes are important persistent pollutants of textile industry effluents. Reduction of these dyes to their corresponding aromatic amines under anaerobic conditions can be used to initiate biodegradation. Since electron transfer is suggested to be rate limiting, redox mediators are being considered to improve dye reduction kinetics. This study evaluates the use of riboflavin, the redox active moiety of common occurring enzyme cofactors, as a redox mediator to accelerate the reduction of the azo dye, mordant yellow 10 (MY10). Dye reduction was found to follow zero order kinetics, the total rate constant (Vtotal) could be separated into two components: the rate of reduction due to direct contact between enzymes in the sludge with the dye (Vdirect); and the rate of reduction mediated by riboflavin (Vmediated). Riboflavin increased the Vtotal by 61% at extremely sub-stoichiometric concentrations of 9.1 μmol l-1, which corresponded to a molar riboflavin:dye ratio of 1:60. The accelerating effect of riboflavin displayed saturation kinetics at higher concentrations, with a maximum increase of Vtotal of approximately 2-fold. A model is presented which assumes that Vmediated depends on the activity of riboflavin reductase (RR) and thus follows Michaelis-Menton kinetics with respect to the riboflavin concentration. The half-velocity constant (Km) was very low (6.3 μmol l-1), indicating a high affinity of the sludge RR for riboflavin. Both Vdirect and Vmediated were found to be proportional to the assay sludge concentration. The results taken as a whole indicate that vitamin levels of riboflavin can be utilized to improve the kinetics of azo dye reduction during anaerobic treatment.

Potentials of high-temperature anaerobic treatment and redox mediators for the reductive decolorization of azo dyes from textile wastewaters

2006 ◽  
Vol 54 (2) ◽  
pp. 151-156 ◽  
Author(s):  
A.B. Dos Santos ◽  
F.J. Cervantes ◽  
J.B. van Lier
Keyword(s):  
High Temperature ◽  
Azo Dyes ◽  
Environmental Problem ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Health Concern ◽  
Redox Mediators ◽  
Reductive Decolorization ◽  
Made In ◽  
Textile Wastewaters

The discharge of dye-colored wastewaters in surface water represents a serious environmental problem because it may decrease the water transparency, therefore having an effect on photosynthesis, and a public health concern because dyes and their reducing products are carcinogenic. In recent years, big achievements have been made in the use of anaerobic granular sludge not only on colored wastewaters but also on the detoxification of other xenobiotics compounds. This paper compiles some important findings related to the potentials of high-temperature anaerobic treatment and redox mediators on the reductive decolorization of azo dyes from textile wastewaters.

Efficient anaerobic treatment of synthetic textile wastewater in a UASB reactor with granular sludge enriched with humic acids supported on alumina nanoparticles

2015 ◽  
Vol 26 (4) ◽  
pp. 289-298 ◽  
Author(s):  
Francisco J. Cervantes ◽  
Rafael Gómez ◽  
Luis H. Alvarez ◽  
Claudia M. Martinez ◽  
Virginia Hernandez-Montoya
Keyword(s):  
Humic Acids ◽  
Granular Sludge ◽  
Textile Wastewater ◽  
Anaerobic Treatment ◽  
Alumina Nanoparticles ◽  
Uasb Reactor

Anaerobic Treatment of Polyethylene Terephthalate (PET) Wastewater from Lab to Full Scale

1999 ◽  
Vol 40 (8) ◽  
pp. 229-236 ◽  
Author(s):  
F. Fdz-Polanco ◽  
M. D. Hidalgo ◽  
M. Fdz-Polanco ◽  
P. A. García Encina
Keyword(s):  
Polyethylene Terephthalate ◽  
Loading Rate ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Foam Formation ◽  
Organic Loading ◽  
Start Up

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.

Effect of hydraulic retention time on pretreatment of blended municipal sludge

2011 ◽  
Vol 64 (4) ◽  
pp. 967-973
Author(s):  
S. Koyunluoglu-Aynur ◽  
R. Riffat ◽  
S. Murthy
Keyword(s):  
Retention Time ◽  
Volatile Fatty Acids ◽  
Hydraulic Retention Time ◽  
Operating Conditions ◽  
Methane Yield ◽  
Municipal Sludge ◽  
Volatile Solids ◽  
Significant Difference ◽  
Autothermal Thermophilic Aerobic Digestion ◽  
Pretreatment Processes

The objective of the present work was to evaluate the effect of hydraulic retention time (HRT) on hydrolysis and acidogenesis for the pretreatment processes: acid phase digestion (APD) and autothermal thermophilic aerobic digestion (ATAD) using blended municipal sludge. The effect of the different pretreatment steps on mesophilic anaerobic digestion (MAD) was evaluated in terms of methane yield, keeping the operating conditions of the MAD the same for all systems. Best operating conditions for both APD and ATAD were observed for 2.5 d HRT with high total volatile fatty acids (tVFA), and the highest methane yield observed for MAD. No significant difference was observed between the two processes in terms of overall volatile solids (VS) reduction with same total HRT. The autothermal process produced heat of 14,300 J/g VS removed from hydrolytic and acetogenic reactions without compromising overall methane yields when the HRT was 2.5 d or lower and the total O2 used was 0.10 m3 O2/g VS added or lower. However, the process needs the input of oxygen and engineering analysis should balance these differences when considering the relative merits of the two pretreatment processes. This is the first study of its kind directly comparing these two viable pretreatment processes with the same sludge.

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