Investigation of affecting parameters on treating high-strength compost leachate in a hybrid EGSB and fixed-bed reactor followed by electrocoagulation–flotation process

2015 ◽  
Vol 95 ◽  
pp. 1-11 ◽  
Author(s):  
W. Dastyar ◽  
T. Amani ◽  
Sh. Elyasi
Keyword(s):  
Fixed Bed ◽  
High Strength ◽  
Fixed Bed Reactor ◽  
Flotation Process ◽  
Compost Leachate

Treatment of high-strength pharmaceutical wastewater by electrocoagulation combined with anaerobic process

2010 ◽  
Vol 61 (2) ◽  
pp. 463-472 ◽  
Author(s):  
A. M. Deshpande ◽  
S. Satyanarayan ◽  
S. Ramakant
Keyword(s):  
Current Density ◽  
Combined Treatment ◽  
Fixed Bed ◽  
High Strength ◽  
Operating Conditions ◽  
Fixed Bed Reactor ◽  
Organic Load ◽  
Pharmaceutical Wastewater ◽  
Pre Treatment ◽  
Marginal Improvement

This article discusses a combined treatment system comprising electrocoagulation (EC) as a pre-treatment followed by anaerobic fixed film fixed bed reactor (AFFBR) for treatment of high strength pharmaceutical wastewater. The effect of various operating parameters such as pH, current density and electrolysis duration on COD, BOD and colour removal was studied. The maximum removals for COD, BOD and colour under optimal operating conditions i.e. pH 7.2, current density (CD) of 80 A/m2 and electrolysis time of 25 minutes were 24%, 35% and 70.25% respectively. Increase in current density has resulted in decrease in electrolysis duration with marginal improvement in treatment efficiency. The efficiency of removal is discussed in terms of kg CODr A−1m−2h−1 and energy consumption as Wh kg−1CODr. The effluents obtained after EC were treated by AFFBR at various organic loading rates (OLRs) and hydraulic retention times (HRTs). The results indicated removals in the range of 80–90% for COD and 86–94% for BOD respectively, at OLRs between 0.6 to 4.0 Kg COD/m3 d at an HRT of 2 days. The total gas quantity increased with increase in both HRT and OLR up to a loading of 6 Kg COD/m3/d but it did not commensurate with organic load. The results indicated that the combined treatment option is competitive and can be used effectively for high strength wastewaters.

Operational Behaviour of an Industrial Fixed Bed Reactor for Biomethanation of Alcohol Slops from Different Crops

1990 ◽  
Vol 22 (1-2) ◽  
pp. 385-394 ◽  
Author(s):  
P. Weiland ◽  
H. Thomsen
Keyword(s):  
Fixed Bed ◽  
High Strength ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Fixed Bed Reactor ◽  
Two Phase ◽  
Fixed Bed Reactors ◽  
Industrial Unit ◽  
One Year ◽  
Better Than

Distillery slops from a multicrop ethanol plant are difficult to treat anaerobically, because the composition and load changes throughout the year due to processing of different sugar-and starch-containing crops. For achieving high COD removal efficiencies and good process stabilities at medium strength loading rates, a two-phase anaerobic treatment process with a fixed-bed reactor for biomethanation was developed and tested in pilot-scale. On the basis of these experiments a full-scale unit with 1,800 m3 reactor volume was erected, which has been in operation for more than one year. The fixed-bed reactor is operated with COD loads up to 10 kg COD/m3d at hydraulic retention times of about 5 days. A variety of highly concentrated slops can be treated successfully with COD removals from 85 % to over 90 %. The fixed-bed reactor withstood sudden changes in wastewater strength and composition and is able to handle hydraulic overloads. Operational data from the industrial unit show that the performance and reliability of the fixed-bed reactor is much better than a conventional contact system, which was operated in a parallel run in the same scale. The results show, that the application of fixed-bed reactors can be recommended for a wide variety of high-strength wastewaters with low suspended solids contents.

scholarly journals Toward the Sustainable Synthesis of Propanols from Renewable Glycerol over MoO3-Al2O3 Supported Palladium Catalysts

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 385 ◽  
Author(s):  
Shanthi Samudrala ◽  
Sankar Bhattacharya
Keyword(s):  
Catalytic Activity ◽  
Palladium Catalysts ◽  
Fixed Bed ◽  
Value Added ◽  
High Strength ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Glycerol Conversion

The catalytic conversion of glycerol to value-added propanols is a promising synthetic route that holds the potential to overcome the glycerol oversupply from the biodiesel industry. In this study, selective hydrogenolysis of 10 wt% aqueous bio-glycerol to 1-propanol and 2-propanol was performed in the vapor phase, fixed-bed reactor by using environmentally friendly bifunctional Pd/MoO3-Al2O3 catalysts prepared by wetness impregnation method. The physicochemical properties of these catalysts were derived from various techniques such as X-ray diffraction, NH3-temperature programmed desorption, scanning electron microscopy, 27Al NMR spectroscopy, surface area analysis, and thermogravimetric analysis. The catalytic activity results depicted that a high catalytic activity (>80%) with very high selectivity (>90%) to 1-propanol and 2-propanol was obtained over all the catalysts evaluated in a continuously fed, fixed-bed reactor. However, among all others, 2 wt% Pd/MoO3-Al2O3 catalyst was the most active and selective to propanols. The synergic interaction between the palladium and MoO3 on Al2O3 support and high strength weak to moderate acid sites of the catalyst were solely responsible for the high catalytic activity. The maximum glycerol conversion of 88.4% with 91.3% selectivity to propanols was achieved at an optimum reaction condition of 210 ∘ C and 1 bar pressure after 3 h of glycerol hydrogenolysis reaction.

Role of filter media in an anaerobic fixed-bed reactor

1995 ◽  
Vol 31 (9) ◽  
pp. 137-144 ◽  
Author(s):  
T. Miyahara ◽  
M. Takano ◽  
T. Noike
Keyword(s):  
Anaerobic Bacteria ◽  
Fixed Bed ◽  
Methanogenic Bacteria ◽  
The Other ◽  
Fixed Bed Reactor ◽  
Filter Media ◽  
Fixed Bed Reactors ◽  
Attached Bacteria ◽  
The Relationship

The relationship between the filter media and the behaviour of anaerobic bacteria was studied using anaerobic fixed-bed reactors. At an HRT of 48 hours, the number of suspended acidogenic bacteria was higher than those attached to the filter media. On the other hand, the number of attached methanogenic bacteria was more than ten times as higher than that of suspended ones. The numbers of suspended and deposited acidogenic and methanogenic bacteria in the reactor operated at an HRT of 3 hours were almost the same as those in the reactor operated at an HRT of 48 hours. Accumulation of attached bacteria was promoted by decreasing the HRT of the reactor. The number of acidogenic bacteria in the reactor packed sparsely with the filter media was higher than that in the closely packed reactor. The number of methanogenic bacteria in the sparsely packed reactor was lower than that in the closely packed reactor.

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