Granulation in an upflow anaerobic sequencing batch reactor treating disintegrated waste activated sludge

2005 ◽  
Vol 52 (12) ◽  
pp. 105-111 ◽  
Author(s):  
K.Y. Park ◽  
D.Y. Kim ◽  
T.H. Chung
Keyword(s):  
Activated Sludge ◽  
Batch Reactor ◽  
Spherical Shape ◽  
Granular Sludge ◽  
Gas Production ◽  
High Rate ◽  
Waste Activated Sludge ◽  
Batch Mode ◽  
Granule Formation ◽  
Methanogenic Activity

An upflow anaerobic reactor operated with a sequencing batch mode to enhance high rate digestion of raw and thermally disintegrated waste activated sludge with formation of granules. The gas production rate doubled when disintegrated waste activated sludge was introduced. Gradual granulation took place and the dispersed particles become coarse granulation as the operation continued. The granular sludge showed relatively higher specific methanogenic activity than the dispersed sludge. Bacterial morphology by a scanning electron microscope showed diversity of bacteria such as filamentous, rod and spherical shape in the section of granules. Filamentous bacteria, which might support the frame of a granule, were observed as long chains at the outer surface. Meanwhile, rod and spherical bacteria, which might play a role in the initial stage of granule formation, were observed from the inner surface of the granule. High rate digestion of sludge along with efficient liquid–solids separation was achieved due mainly to development of sludge granules within the upflow reactor.

Biosorption of Nickel from Batch Reactor using the Powder of Waste Activated Sludge

2011 ◽  
Vol 5 (5) ◽  
pp. 461-470 ◽  
Author(s):  
Reza Fouladi Fard ◽  
Gholamreza Nabi Bidhendi ◽  
Ali Akbar Azimi
Keyword(s):  
Activated Sludge ◽  
Batch Reactor ◽  
Waste Activated Sludge

The SBR and its biofilm application potentials

2004 ◽  
Vol 50 (10) ◽  
pp. 1-10 ◽  
Author(s):  
P.A. Wilderer ◽  
B.S. McSwain
Keyword(s):  
Activated Sludge ◽  
Batch Reactor ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Waste Streams ◽  
Sludge Flocs ◽  
Biofilm Reactors ◽  
Volatile Organic ◽  
High Level ◽  
Slow Growing

Twenty plus years of experience, innovation, and research in the field of biological wastewater treatment and biofilm applications lead to the conclusion that biofilms are in many cases more desirable in reactors than suspended activated sludge. Biofilm reactors can provide very long biomass residence times even when the hydraulic influent loading is low. This makes them particularly suitable when treatment requires slow growing organisms with poor biomass yield or when the wastewater concentration is too low to support growth of activated sludge flocs. Regardless of the settling characteristics of biological aggregates or the hydraulic influent loading the metabolic activity in the reactor can be maintained at a high level. This paper reviews the application of biofilms in sequencing batch reactor (SBR) systems to treat non-readily biodegradable substrates, volatile organic waste constituents, complex waste streams requiring co-metabolism, and particulate wastewaters. Recent research using the SBR to form aerobic granular sludge as a special application of biofilms is also discussed.

scholarly journals Methanosarcinaceae and Acetate-Oxidizing Pathways Dominate in High-Rate Thermophilic Anaerobic Digestion of Waste-Activated Sludge

2013 ◽  
Vol 79 (20) ◽  
pp. 6491-6500 ◽  
Author(s):  
Dang P. Ho ◽  
Paul D. Jensen ◽  
Damien J. Batstone
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Retention Time ◽  
Elevated Temperatures ◽  
Stable Carbon Isotope ◽  
High Rate ◽  
Continuous Reactor ◽  
Waste Activated Sludge ◽  
Acetate Oxidation ◽  
Syntrophic Acetate Oxidation

ABSTRACTThis study investigated the process of high-rate, high-temperature methanogenesis to enable very-high-volume loading during anaerobic digestion of waste-activated sludge. Reducing the hydraulic retention time (HRT) from 15 to 20 days in mesophilic digestion down to 3 days was achievable at a thermophilic temperature (55°C) with stable digester performance and methanogenic activity. A volatile solids (VS) destruction efficiency of 33 to 35% was achieved on waste-activated sludge, comparable to that obtained via mesophilic processes with low organic acid levels (<200 mg/liter chemical oxygen demand [COD]). Methane yield (VS basis) was 150 to 180 liters of CH4/kg of VSadded. According to 16S rRNA pyrotag sequencing and fluorescence in situ hybridization (FISH), the methanogenic community was dominated by members of theMethanosarcinaceae, which have a high level of metabolic capability, including acetoclastic and hydrogenotrophic methanogenesis. Loss of function at an HRT of 2 days was accompanied by a loss of the methanogens, according to pyrotag sequencing. The two acetate conversion pathways, namely, acetoclastic methanogenesis and syntrophic acetate oxidation, were quantified by stable carbon isotope ratio mass spectrometry. The results showed that the majority of methane was generated by nonacetoclastic pathways, both in the reactors and in off-line batch tests, confirming that syntrophic acetate oxidation is a key pathway at elevated temperatures. The proportion of methane due to acetate cleavage increased later in the batch, and it is likely that stable oxidation in the continuous reactor was maintained by application of the consistently low retention time.

High rate mesophilic, thermophilic, and temperature phased anaerobic digestion of waste activated sludge: A pilot scale study

2012 ◽  
Vol 32 (6) ◽  
pp. 1196-1201 ◽  
Author(s):  
David Bolzonella ◽  
Cristina Cavinato ◽  
Francesco Fatone ◽  
Paolo Pavan ◽  
Franco Cecchi
Keyword(s):  
Anaerobic Digestion ◽  
Activated Sludge ◽  
Pilot Scale ◽  
High Rate ◽  
Waste Activated Sludge

Sequencing batch reactor (SBR) as optimal method for production of granular activated sludge (GAS) – fluid dynamic investigations

2007 ◽  
Vol 55 (8-9) ◽  
pp. 151-158 ◽  
Author(s):  
B.E. Zima ◽  
L. Díez ◽  
W. Kowalczyk ◽  
A. Delgado
Keyword(s):  
Multiphase Flow ◽  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Fluid Dynamic ◽  
Batch Reactor ◽  
Aerobic Condition ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Major Influence ◽  
Optimal Method

Fluid dynamic investigations of multiphase flow (fluid, air, granules) in a sequencing batch reactor (SBR) are presented. SBR can be considered as an attractive technology for cultivation of granular activated sludge (GAS). Granulation is a complicated process and its mechanism is not fully understood yet. Many factors influence the formation and structure of aerobic granular sludge in a bioreactor. Extracellular polymer substances (EPS) and superficial gas velocity (SGV) play a crucial role for granules formation. Additionally, it is supposed that EPS production is stimulated by mechanical forces. It is also assumed that hydrodynamic effects have a major influence on the formation, shape and size of GAS in SBR under aerobic condition. However, the influence of stress on granulation is poorly investigated. Thus, in the present paper, fluid dynamic investigations of multiphase flow in a SBR, particularly effect of normal and shear strain, are reported. In order to analyse multiphase flow in the SBR, optical in-situ techniques with particle image velocimetry (PIV) and particle tracking velocimetry (PTV) are implemented. Obtained results show a characteristic flow pattern in a SBR. It is pointed out that additional effects like particle-wall collisions, inter particle collisions, erosion can also affect significantly granules formation.

Anaerobic treatment of complex wastewater and waste activated sludge – application of an upflow anaerobic solid removal (UASR) reactor for the removal and pre-hydrolysis of suspended COD

1997 ◽  
Vol 35 (10) ◽  
pp. 121-128 ◽  
Author(s):  
Grietje Zeeman ◽  
Wendy T. M. Sanders ◽  
Kaijun Y. Wang ◽  
Gatze Lettinga
Keyword(s):  
Activated Sludge ◽  
Suspended Solids ◽  
Anaerobic Treatment ◽  
Dairy Wastewater ◽  
Waste Activated Sludge ◽  
Solid Retention Time ◽  
Methanogenic Activity ◽  
Wastewater Systems ◽  
Co Precipitation ◽  
Solids Removal

The application of one phase anaerobic wastewater systems for the treatment of complex wastewaters containing high amounts of suspended solids or lipids is usually limited by accumulation of these compounds in the sludge bed. This accumulation reduces the solid retention time and methanogenic activity of the sludge. The aim of the presented research was to achieve removal of suspended solids or lipids in an Upflow Anaerobic Solids Removal reactor to make higher reactor loadings possible. Raw sewage, waste activated sludge and dairy wastewater were pre-treated in an UASR reactor. When treating the raw sewage at 17°C and 3.0 h HRT 65% of the suspended COD could be entrapped in the sludge bed. Treatment of 2 g COD/l waste activated sludge at 9.6h HRT and 20°C resulted in 98% removal of the suspended COD. In both cases only 6–7% acidification of the complex wastewater took place. Dairy wastewater consists of mainly dissolved and colloidal COD. The lipids are surrounded by a protein membrane. These proteins will precipitate at pH &lt;4.6 resulting in co-precipitation of the lipids. At 20°C and 4.5h HRT 57% of the lactose present in the wastewater was acidified, resulting in a pH of 4.0 and 98% lipids removal. It was concluded that the UASR reactor can achieve very high removal efficiencies for CODss and lipids, yet the retained COD is just partly hydrolysed. The produced sludge can be post-digested at thermophilic or mesophilic conditions to produce methane gas.

Anaerobic Digestion of Distillery Wastewater in a Two-Phase UASB System

1992 ◽  
Vol 25 (7) ◽  
pp. 361-371 ◽  
Author(s):  
H.-S. Shin ◽  
B.-U. Bae ◽  
J.-J. Lee ◽  
B.-C. Paik
Keyword(s):  
Granular Sludge ◽  
Methanogenic Bacteria ◽  
Gas Production ◽  
High Rate ◽  
Uasb Reactor ◽  
Two Phase ◽  
Distillery Wastewater ◽  
Electron Microscopes ◽  
Different Color ◽  
Methanogenic Phase

A two-phase UASB system was operated for high-rate treatment of concentrated distillery wastewater. The phase separation was obtained by adjusting pH in each reactor. When influent SS concentration was 4.1 g/l, the first phase UASB reactor was effectively operated up to the loading rate of 16.5 kg COD/m3.day, producing 3.9 g HAc/l.day. In the methanogenic UASB reactor, loading rates up to 44 kg COD/m3.day could be applied while removing 80 % of influent COD with a specific gas production of 16.5 l/l.day. After the formation of granular sludge in both reactors, it was possible to maintain the appropriate pH in the first phase only by recirculating the effluent from the methanogenic phase without the addition of alkaline chemicals. The morphological study on the granular sludge consortia was made with both scanning and transmission electron microscopes. It was interesting to find the granules of different color and shape in the acidogenic phase in 90 days and in the methanogenic phase in 120 days after start-up. The acidogenic granular sludge mainly consisted of long chains of large rods, short plump rods, and various size of cocci, which have a different shape and cytoplasmic appearance from common methanogenic bacteria. Whereas the long multicellular filaments of Methanothrix spp. were prevalent in the methanogenic granule, diverse bacteria were entrapped therein.

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