scholarly journals Simple estimation of granule size distribution and sludge bed porosity in a UASB reactor

2013 ◽  
Vol 10 (1) ◽  
pp. 73-79
Keyword(s):  
Size Distribution ◽  
Granular Sludge ◽  
Granule Size ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Reactor Performance ◽  
Efficient Operation ◽  
Mathematical Algorithm ◽  
Bed Porosity

Granular sludge is the key factor for an efficient operation of an upflow anaerobic sludge blanket (UASB) reactor. In order to monitor the granularity of anaerobic sludge, the determination of the granule size distribution is of vital importance. Another critical parameter for the UASB reactor performance is the sludge bed porosity. For this reason, several techniques have been proposed, however they are either tedious, imprecise or expensive and hardly applicable in full scale treatment plants. There was then the need for a simple and low cost technique. This technique involves the determination of the settling velocities of a sludge sample and of extrapolating the corresponding diameters using a mathematical algorithm. In the proposed algorithm, the granules density was calculated, the flow regime was examined and finally the granule size distribution was obtained. Some very important correlations were suggested by the experimental results. The granule density and diameter as well as the sludge bed porosity were strongly correlated with the VSS/TSS ratio.

Thermophilic anaerobic digestion of methanol in UASB reactor

2001 ◽  
Vol 44 (4) ◽  
pp. 129-136 ◽  
Author(s):  
P. L. Paulo ◽  
B. Jiang ◽  
S. Rebac ◽  
L. Hulshoff Pol ◽  
G. Lettinga
Keyword(s):  
Temperature Drop ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Methanol Conversion ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Reactor Performance ◽  
Thermophilic Conditions ◽  
Main Components ◽  
Main Component

A 5.1 L laboratory scale upflow anaerobic sludge bed (UASB) reactor was operated at 55°C over 130 days in order to investigate the feasibility of treating methanol-containing wastewater under thermophilic conditions, focussing on start-up and process stability. Batch assays were conducted to elucidate the most probable pathway for methanol conversion. The results demonstrated a good performance, with a chemical oxygen demand (COD) removal averaging 82% throughout the experiment. No significant VFA accumulation was detected in the effluent, even with bicarbonate concentration exceeding 20 mM. Acetate was the main component of the VFA at relatively low organic loading rates (OLR). At high OLR, the main components were propionate and butyrate. Reactor performance was hardly affected when the system was exposed to non-optimal conditions, i.e., temperature drop, overloading and no feeding. Good thermophilic granular sludge was retained in the reactor. Washout of biomass was not severe during the experiment. From the pathway analysis it could be concluded that indirect pathways play an important role in the methanol degradation by the cultivated consortia.

Determination of granule size distribution in a UASB reactor

2008 ◽  
Vol 86 (4) ◽  
pp. 660-664 ◽  
Author(s):  
Apostolos Vlyssides ◽  
Elli Maria Barampouti ◽  
Sofia Mai
Keyword(s):  
Size Distribution ◽  
Granule Size ◽  
Uasb Reactor

scholarly journals Microbial Diversity Dynamics in a Methanogenic-Sulfidogenic UASB Reactor

2021 ◽  
Vol 18 (3) ◽  
pp. 1305
Author(s):  
E. Fernández-Palacios ◽  
Xudong Zhou ◽  
Mabel Mora ◽  
David Gabriel
Keyword(s):  
Paper Industry ◽  
Chemical Species ◽  
Methanogenic Archaea ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Long Run

In this study, the long-term performance and microbial dynamics of an Upflow Anaerobic Sludge Blanket (UASB) reactor targeting sulfate reduction in a SOx emissions treatment system were assessed using crude glycerol as organic carbon source and electron donor under constant S and C loading rates. The reactor was inoculated with granular sludge obtained from a pulp and paper industry and fed at a constant inlet sulfate concentration of 250 mg S-SO42−L−1 and a constant C/S ratio of 1.5 ± 0.3 g Cg−1 S for over 500 days. Apart from the regular analysis of chemical species, Illumina analyses of the 16S rRNA gene were used to study the dynamics of the bacterial community along with the whole operation. The reactor was sampled along the operation to monitor its diversity and the changes in targeted species to gain insight into the performance of the sulfidogenic UASB. Moreover, studies on the stratification of the sludge bed were performed by sampling at different reactor heights. Shifts in the UASB performance correlated well with the main shifts in microbial communities of interest. A progressive loss of the methanogenic capacity towards a fully sulfidogenic UASB was explained by a progressive wash-out of methanogenic Archaea, which were outcompeted by sulfate-reducing bacteria. Desulfovibrio was found as the main sulfate-reducing genus in the reactor along time. A progressive reduction in the sulfidogenic capacity of the UASB was found in the long run due to the accumulation of a slime-like substance in the UASB.

Acid Endurance and Sorption of Zn2+ of Anaerobic Granular Sludge Acclimated by Flue Gas Pretreatment Wastewater

2013 ◽  
Vol 634-638 ◽  
pp. 182-186
Author(s):  
Juan Wang ◽  
Qin Zhong
Keyword(s):  
Flue Gas ◽  
Ph Value ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Anaerobic Granular Sludge ◽  
Methanogenic Activity ◽  
Activity Inhibition ◽  
Anaerobic Sludge Blanket

With the aim to use anaerobic granular sludge, the methanogenic activity inhibition and recovery of anaerobic granular sludge from an industrial anaerobic reactor (s1) were investigated by measuring the methane volume at low pH. A lab-scale upflow anaerobic sludge blanket (UASB) reactor was inoculated with s1.s1 was used to remove Zn2+ in wastewater. The results show that activity of s1 is similar when the pH value is 6.5 to 7.0. The methane volume is obviously decreased when the pH value is 6.0. The activity is completely inhibited when the pH value is 4.5. The activity is fully recovered when the pH is above 6.5 and hardly recovers when the pH fell to 4.5. The main Zn2+ removal mechanism is chemical adsorption.

Advanced Reactor Design, Operation and Economy

1986 ◽  
Vol 18 (12) ◽  
pp. 99-108 ◽  
Author(s):  
Gatze Lettinga ◽  
Look Hulshoff Pol
Keyword(s):  
Suspended Solids ◽  
Granular Sludge ◽  
High Rate ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Internal Circulation ◽  
Inlet System ◽  
Anaerobic Sludge Blanket ◽  
Feed Inlet

Of the high rate anaerobic wastewater treatment systems the UASB (Upflow Anaerobic Sludge Blanket) reactor has found the widest application. Therefore the attention with respect to design, operation and economy will be focussed on this reactor type. In designing a UASB reactor specific attention is needed for the GSS (Gas-Solids Separator) device and the feed inlet system. For soluble wastewater generally no phase separation is required. Only for wastewaters high in suspended solids pre-acidification in a separate acidification reactor can be beneficial. Increasing attention is given to the development of modified UASB systems, such as a combination of a sludge bed reactor and an anaerobic filter. Other possible modified UASB systems may be found in a FS (Floating Settling) UASB reactor, the EGSB (Expanded Granular Sludge Bed) reactor and the UASB IC (Internal Circulation) reactor. As many factors are involved in the costs of a UASB reactor, only some rough data on reactor costs are presented.

Start up of Thermophilic UASB (Upflow Anaerobic Sludge Blanket) Reactors Using Micro-Carrier and Mesophilic Granular Sludge

1992 ◽  
Vol 26 (3-4) ◽  
pp. 877-886 ◽  
Author(s):  
T. Ohtsuki ◽  
M. Watanabe ◽  
Y. Miyaji
Keyword(s):  
High Performance ◽  
Ph Dependence ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Phase System ◽  
Two Phase ◽  
Start Up ◽  
Initial Seed

Two start-up methods of thermophilic UASB reactor were investigated for fast start-ups; one utilized micro-carrier as an initial support material and the other used intact mesophilic UASB granules as an initial seed. With both methods thermophilic granules having high activity were obtained in less than 3 months, even with acidified wastewater. Maximum sludge load for VFA substrate and sugar substrate were 3.2 and 0.9 kgCOD/kgVSS/day, respectively. Pre-acidogenesis was indispensable for high-performance treatment of sugar-containing substrate. It was proven that with a two-phase system sludge load could be raised to 3.0 kgCOD/kgVSS/day for sugar containing wastewaters. Some features of obtained sludge were examined, including maximum substrate utilizing activities, temperature dependence, pH dependence, and activity deterioration under lower loading conditions.

scholarly journals Anaerobic treatment of domestic sewage at low temperature

2001 ◽  
Vol 44 (4) ◽  
pp. 33-40 ◽  
Author(s):  
T. Elmitwalli ◽  
Gr. Zeeman ◽  
G. Lettinga
Keyword(s):  
Low Temperature ◽  
Granular Sludge ◽  
Anaerobic Treatment ◽  
Domestic Sewage ◽  
Uasb Reactor ◽  
The Novel ◽  
Reactor Performance ◽  
Batch Tests ◽  
Pre Treatment ◽  
Attached Form

The results of research concerning the feasibility of anaerobic treatment of domestic sewage at low temperature are summarized in this article. The batch tests demonstrated a high biodegradability of domestic sewage at 20°C (74%). Both batch and continuous experiments for the treatment of domestic sewage showed that the removal of SS prior to anaerobic treatment of domestic sewage not only provides a stable reactor performance but also improves the removal of both colloidal (CODcol) and dissolved COD (CODdis). The results of the pre-treatment of domestic sewage in an anaerobic filter (AF) and an anaerobic hybrid (AH) reactor showed that the AF reactor is an efficient process for the removal of suspended COD (CODss), viz. 82%, at an HRT of 4 h and 13°C. The novel AF reactor consists of vertical sheets of reticulated polyurethane foam with knobs, where the biomass was only in attached form. For the treatment of pre-settled sewage at 13°C, the AH reactor, with granular sludge, showed a higher total COD (CODt) removal than the UASB reactor as a result of higher CODcol removal. Therefore, the performance of a two-step system, AF+AH (with granular sludge) reactor, was investigated with different HRTs at 13°C. For optimization of CODss and CODdis an HRT of 4+4 h is needed, while for optimization of CODcol removal an HRT of 4+8 h is required. A CODt removal of 71% was achieved with 60% conversion to methane from the removed CODt when the AF+AH system was operated at an HRT of 4+8 h at 13°C.

Start-up of a thermophilic upflow anaerobic sludge bed (UASB) reactor with mesophilic granular sludge

1992 ◽  
Vol 37 (1) ◽  
pp. 130-135 ◽  
Author(s):  
Jules B. van Lier ◽  
Katja C. F. Grolle ◽  
Alfons J. M. Stams ◽  
Everly Conway de Macario ◽  
Gatze Lettinga
Keyword(s):  
Granular Sludge ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Start Up

Anaerobic treatment of crude glycerol from biodiesel production

2015 ◽  
Vol 72 (8) ◽  
pp. 1383-1389 ◽  
Author(s):  
M. M. Nakazawa ◽  
W. R. S. Silva Júnior ◽  
M. T. Kato ◽  
S. Gavazza ◽  
L. Florencio
Keyword(s):  
Crude Glycerol ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Experimental Period ◽  
Anaerobic Treatment ◽  
Biodiesel Production ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Reactor Performance

In this study, we evaluated the use of an up-flow anaerobic sludge blanket (UASB) reactor to treat crude glycerol obtained from cottonseed biodiesel production. The laboratory-scale UASB reactor (7.0 L) was operated at ambient temperature of 26.5°C with chemical oxygen demand (COD) concentrations between 0.5 and 8.0 g/L. The volatile fatty acid contents, pH, inorganic salt contents and biogas production were monitored during a 280-day experimental period. Molecular biology techniques were used to assess the microbial diversity in the bioreactor. The reactor achieved COD removal efficiencies of up to 92% except during one phase when the efficiency decreased to 81%. Biogas production remained stable throughout the experimental period, when the fraction converted to methane reached values as high as 68%. The profile of the denaturing gradient gel electrophoresis (DGGE) bands suggested slight changes in the microbial community during reactor operation. The overall results indicated that the crude glycerol from biodiesel production can serve as a suitable substrate for anaerobic degradation with a stable reactor performance and biogas production as long as the applied organic loads are up to 8.06 kg COD/m3·d.

Impact of aluminum chloride on process performance and microbial community structure of granular sludge in an upflow anaerobic sludge blanket reactor for natural rubber processing wastewater treatment

2016 ◽  
Vol 74 (2) ◽  
pp. 500-507 ◽  
Author(s):  
Nguyen Thi Thanh ◽  
Takahiro Watari ◽  
Tran Phuong Thao ◽  
Masashi Hatamoto ◽  
Daisuke Tanikawa ◽  
...  
Keyword(s):  
Community Structure ◽  
Microbial Community ◽  
Natural Rubber ◽  
Microbial Community Structure ◽  
Aluminum Chloride ◽  
Granular Sludge ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Anaerobic Sludge ◽  
Anaerobic Sludge Blanket

In this study, granular sludge formation was carried out using an aluminum chloride supplement in an upflow anaerobic sludge blanket (UASB) reactor treating natural rubber processing wastewater. Results show that during the first 75 days after the start-up of the UASB reactor with an organic loading rate (OLR) of 2.65 kg-COD·m−3·day−1, it performed stably with a removal of 90% of the total chemical oxygen demand (COD) and sludge still remained in small dispersed flocs. However, after aluminum chloride was added at a concentration of 300 mg·L−1 and the OLR range was increased up to 5.32 kg-COD·m−3·day−1, the total COD removal efficiency rose to 96.5 ± 2.6%, with a methane recovery rate of 84.9 ± 13.4%, and the flocs began to form granules. Massively parallel 16S rRNA gene sequencing of the sludge retained in the UASB reactor showed that total sequence reads of Methanosaeta sp. and Methanosarcina sp., reported to be the key organisms for granulation, increased after 311 days of operation. This indicates that the microbial community structure of the retained sludge in the UASB reactor at the end of the experiment gave a good account of itself in not only COD removal, but also granule formation.

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