Microbial activity of biofilm during start-up period of anaerobic hybrid reactor at low and high upflow feeding velocity

2003 ◽  
Vol 48 (8) ◽  
pp. 79-87 ◽  
Author(s):  
B. Suraruksa ◽  
A. Nopharatana ◽  
P. Chaiprasert ◽  
M. Tanticharoen ◽  
S. Bhumiratana
Keyword(s):  
Microbial Growth ◽  
Laser Scanning Microscopy ◽  
Lower Amount ◽  
Hybrid Reactor ◽  
Lower Velocity ◽  
Start Up ◽  
Attached Biomass ◽  
Anaerobic Hybrid Reactor ◽  
Biofilm Development ◽  
Initial Biofilm

With an aim to shorten start-up time of an Anaerobic Hybrid Reactor (AHR), initial biofilm development was studied, particularly at different upflow feeding velocities. At a low (0.01 m·h-1) upflow velocity, initial biofilm was found to develop via the attachment of suspended biomass in the packed zone, while microbial growth on the film was insignificant. Contrarily, with higher (1.0 m·h-1) upflow velocity, initial biofilm development was from both microbial attachment and growth on supporting media. Biofilm thickness was determined using confocal laser scanning microscopy (CLSM), which indicated that the biofilm developed faster with the higher velocity, due to the contribution of the microbial growth on supporting media. When operated beyond the initial biofilm development with the lower velocity, both the activity of acetogens and the methanogens increased, although there was a lower amount of attached biomass on the supporting media. Whereas, both groups were found to decrease with higher upflow velocity, but acidogenic activity increased. It can be concluded that higher upflow velocity positively affected the initial stage of biofilm development and has the potential to accelerate attached biomass on supporting media during the initial phase. Subsequently, the upflow velocity should be reduced to the normal rate to enhance the methanogenic activity.

Application of an anaerobic hybrid reactor for petrochemical effluent treatment

2012 ◽  
Vol 65 (12) ◽  
pp. 2098-2105 ◽  
Author(s):  
Mohammad Taghi Jafarzadeh ◽  
Naser Mehrdadi ◽  
Seyed Jamaladdin Hashemian
Keyword(s):  
Biogas Production ◽  
Dairy Wastewater ◽  
Effluent Treatment ◽  
Hybrid Reactor ◽  
Reactor Performance ◽  
Operational Conditions ◽  
Start Up ◽  
Anaerobic Hybrid Reactor ◽  
Petrochemical Wastes

An anaerobic hybrid reactor (UASB/Filter) was used for petrochemical wastewater treatment in mesophilic conditions. The seeded flocculent sludge from a UASB plant treating dairy wastewater, acclimatized to the petrochemical wastes in a two-stage operation. After start up, under steady-state conditions, experiments were conducted at OLRs of between 0.5 and 24 kg TCOD m−3 d−1, hydraulic retention times (HRT) of 4–48 h and up-flow velocities 0.021–0.25 mh−1. Removal efficiencies in the range of 42–86% were achieved at feed TCOD concentrations of 1,000–4,000 mg L−1. The results of reactor performance at different operational conditions and its relations are presented and discussed in this paper. Then, the obtained data are used for determination of kinetic models. The results showed that a second-order model and a modified Stover–Kincannon model were the most appropriate models for this reactor. Finally, the biogas production data were used for the determination of biogas production kinetics.

Influence of Seeding Conditions on Initial Biofilm Development during the Startup of Anaerobic Fluidized Bed Reactors

1989 ◽  
Vol 21 (4-5) ◽  
pp. 157-165 ◽  
Author(s):  
F. Ehlinger ◽  
J. M. Audic ◽  
G. M. Faup
Keyword(s):  
Fluidized Bed ◽  
Future Development ◽  
Protein Concentration ◽  
Specific Activity ◽  
Fluidized Bed Reactor ◽  
Fluidized Bed Reactors ◽  
Support Material ◽  
Biofilm Development ◽  
Initial Biofilm

The characterization of the biofilm of an anaerobic fluidized-bed reactor was completed under standard conditions. The distribution of the fixed protein concentration depended on the level in the reactor. The protein concentration reached 1520 µg.g−1 of support at the top of the reactor and only 1200 µg.g−1 at the bottom after 504 hours of operation but the specific activity of the biofilm was 33×10−4 µM acetate.h−1.mg−1 proteins at the bottom and only 26×10−4 µM.h−1.mg−1 at the top. The efficiency of a fluidized bed reactor and the composition of the biofilm changed with an increase of the pH from 7 to 8.5 during the seeding of the support material. Future development of the biofilm and the specific activity of the support were affected.

scholarly journals Importance of Initial Interfacial Steps during Chalcopyrite Bioleaching by a Thermoacidophilic Archaeon

2020 ◽  
Vol 8 (7) ◽  
pp. 1009
Author(s):  
Camila Safar ◽  
Camila Castro ◽  
Edgardo Donati
Keyword(s):  
High Temperatures ◽  
Laser Scanning ◽  
Laser Scanning Microscopy ◽  
Copper Recovery ◽  
Confocal Laser ◽  
Mineral Surface ◽  
Thermophilic Microorganisms ◽  
Valuable Metals ◽  
Refractory Mineral ◽  
Biofilm Development

Studies of thermophilic microorganisms have shown that they have a considerable biotechnological potential due to their optimum growth and metabolism at high temperatures. Thermophilic archaea have unique characteristics with important biotechnological applications; many of these species could be used in bioleaching processes to recover valuable metals from mineral ores. Particularly, bioleaching at high temperatures using thermoacidophilic microorganisms can greatly improve metal solubilization from refractory mineral species such as chalcopyrite (CuFeS2), one of the most abundant and widespread copper-bearing minerals. Interfacial processes such as early cell adhesion, biofilm development, and the formation of passive layers on the mineral surface play important roles in the initial steps of bioleaching processes. The present work focused on the investigation of different bioleaching conditions using the thermoacidophilic archaeon Acidianus copahuensis DSM 29038 to elucidate which steps are pivotal during the chalcopyrite bioleaching. Fluorescent in situ hybridization (FISH) and confocal laser scanning microscopy (CLSM) were used to visualize the microorganism–mineral interaction. Results showed that up to 85% of copper recovery from chalcopyrite could be achieved using A. copahuensis. Improvements in these yields are intimately related to an early contact between cells and the mineral surface. On the other hand, surface coverage by inactivated cells as well as precipitates significantly reduced copper recoveries.

Evaluating the performance of anaerobic moving bed bioreactor and upflow anaerobic hybrid reactor for treating textile desizing wastewater

2021 ◽  
pp. 108123
Author(s):  
Hafiz Muhammad Aamir Shahzad ◽  
Sher Jamal Khan ◽  
Zeshan ◽  
Yousuf Jamal ◽  
Zunaira Habib
Keyword(s):  
Hybrid Reactor ◽  
Moving Bed ◽  
Anaerobic Hybrid Reactor

scholarly journals Bacterial lipopolysaccharides variably modulate in vitro biofilm formation of Candida species

2010 ◽  
Vol 59 (10) ◽  
pp. 1225-1234 ◽  
Author(s):  
H. M. H. N. Bandara ◽  
O. L. T. Lam ◽  
R. M. Watt ◽  
L. J. Jin ◽  
L. P. Samaranayake
Keyword(s):  
Biofilm Formation ◽  
Laser Scanning ◽  
Significant Inhibition ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Dependent Manner ◽  
Bacterial Lipopolysaccharides ◽  
Species Specific ◽  
Biofilm Development

The objective of this study was to evaluate the effect of the bacterial endotoxin LPS on Candida biofilm formation in vitro. The effect of the LPS of Pseudomonas aeruginosa, Klebsiella pneumoniae, Serratia marcescens and Salmonella typhimurium on six different species of Candida, comprising Candida albicans ATCC 90028, Candida glabrata ATCC 90030, Candida krusei ATCC 6258, Candida tropicalis ATCC 13803, Candida parapsilosis ATCC 22019 and Candida dubliniensis MYA 646, was studied using a standard biofilm assay. The metabolic activity of in vitro Candida biofilms treated with LPS at 90 min, 24 h and 48 h was quantified by XTT reduction assay. Viable biofilm-forming cells were qualitatively analysed using confocal laser scanning microscopy (CLSM), while scanning electron microscopy (SEM) was employed to visualize the biofilm structure. Initially, adhesion of C. albicans was significantly stimulated by Pseudomonas and Klebsiella LPS. A significant inhibition of Candida adhesion was noted for the following combinations: C. glabrata with Pseudomonas LPS, C. tropicalis with Serratia LPS, and C. glabrata, C. parapsilosis or C. dubliniensis with Salmonella LPS (P<0.05). After 24 h of incubation, a significant stimulation of initial colonization was noted for the following combinations: C. albicans/C. glabrata with Klebsiella LPS, C. glabrata/C. tropicalis/C. krusei with Salmonella LPS. In contrast, a significant inhibition of biofilm formation was observed in C. glabrata/C. dubliniensis/C. krusei with Pseudomonas LPS, C. krusei with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. parapsilosis/C. dubliniensis /C. krusei with Salmonella LPS (P<0.05). On further incubation for 48 h, a significant enhancement of biofilm maturation was noted for the following combinations: C. glabrata/C. tropicalis with Serratia LPS, C. dubliniensis with Klebsiella LPS and C. glabrata with Salmonella LPS, and a significant retardation was noted for C. parapsilosis/C. dubliniensis/C. krusei with Pseudomonas LPS, C. tropicalis with Serratia LPS, C. glabrata/C. parapsilosis/C. dubliniensis with Klebsiella LPS and C. dubliniensis with Salmonella LPS (P<0.05). These findings were confirmed by SEM and CLSM analyses. In general, the inhibition of the biofilm development of LPS-treated Candida spp. was accompanied by a scanty architecture with a reduced numbers of cells compared with the profuse and densely colonized control biofilms. These data are indicative that bacterial LPSs modulate in vitro Candida biofilm formation in a species-specific and time-dependent manner. The clinical and the biological relevance of these findings have yet to be explored.

Biofilm development during the start-up of a sulfate-reducing down-flow fluidized bed reactor at different COD/SO42− ratios and HRT

2011 ◽  
Vol 64 (4) ◽  
pp. 910-916 ◽  
Author(s):  
E. Z. Piña-Salazar ◽  
F. J. Cervantes ◽  
M. Meraz ◽  
L. B. Celis
Keyword(s):  
Fluidized Bed ◽  
Granular Sludge ◽  
Fluidized Bed Reactor ◽  
Sulfate Reducing ◽  
Sulfate Removal ◽  
Start Up ◽  
Effective Removal ◽  
Suspended Biomass ◽  
High Sulfate ◽  
Biofilm Development

In sulfate-reducing reactors, it has been reported that the sulfate removal efficiency increases when the COD/SO42− ratio is increased. The start-up of a down-flow fluidized bed reactor constitutes an important step to establish a microbial community in the biofilm able to survive under the operational bioreactor conditions in order to achieve effective removal of both sulfate and organic matter. In this work the influence of COD/SO42− ratio and HRT in the development of a biofilm during reactor start-up (35 days) was studied. The reactor was inoculated with 1.6 g VSS/L of granular sludge, ground low density polyethylene was used as support material; the feed consisted of mineral medium at pH 5.5 containing 1 g COD/L (acetate:lactate, 70:30) and sodium sulfate. Four experiments were conducted at HRT of 1 or 2 days and COD/SO42− ratio of 0.67 or 2.5. The results obtained indicated that a COD/SO42− ratio of 2.5 and HRT 2 days allowed high sulfate and COD removal (66.1 and 69.8%, respectively), whereas maximum amount of attached biomass (1.9 g SVI/L support) and highest sulfate reducing biofilm activity (10.1 g COD-H2S/g VSS-d) was achieved at HRT of 1 day and at COD/sulfate ratios of 0.67 and 2.5, respectively, which suggests that suspended biomass also played a key role in the performance of the reactors.

scholarly journals Performance evaluation of an anaerobic hybrid reactor treating petrochemical effluent

2021 ◽  
Vol 14 ◽  
pp. 51-57
Author(s):  
M.T. Jafarzadeh ◽  
N. Jamshidi ◽  
L. Talebiazar ◽  
R. Aslaniavali
Keyword(s):  
Loading Rate ◽  
Biogas Production ◽  
Dairy Wastewater ◽  
Organic Loading Rate ◽  
Hybrid Reactor ◽  
Petrochemical Wastewater ◽  
Anaerobic Reactors ◽  
Anaerobic Hybrid Reactor ◽  
Study Performance

Organic loading rate (OLR), Hydraulic Retention Time (HRT) and up flow velocity are important parameters significantly affecting microbial ecology and characteristics of anaerobic reactors. In this study, Performance of an anaerobic hybrid reactor (UASB/Filter) at mesophilic condition was evaluated in a 15.4 L reactor receiving petrochemical wastewater. The temperature of influent was adjusted by an inline heat exchanger at around 35 ˚C. The reactor was seeded with flocculent sludge from a UASB plant treating dairy wastewater. The sludge was acclimatized to petrochemical wastewater in twostage operation. After 39 weeks, a COD reduction of 70.3% was obtained at OLR=2.0 kg m-3 d-1 and HRT=18 h. Under steady state conditions, experiments were conducted at OLRs of between 0.5 and 24 kg TCOD m-3 d-1 , hydraulic retention times (HRT) of 4-48 h and up flow velocities 0.021-0.25 m h-1. Removal efficiencies in the range of 42-86% were achieved at feed TCOD concentrations of 1000- 4000 mg L-1 . The biogas production data used for determination of biogas production kinetics. The values of Gmax and GB estimated as 11.173 LL-1d -1 and 85.83 g L-1d -1 , respectively.

Treatment of low strength industrial cluster wastewater by anaerobic hybrid reactor

2008 ◽  
Vol 99 (8) ◽  
pp. 3123-3129 ◽  
Author(s):  
Amit Kumar ◽  
Asheesh Kumar Yadav ◽  
T.R. Sreekrishnan ◽  
Santosh Satya ◽  
C.P. Kaushik
Keyword(s):  
Industrial Cluster ◽  
Hybrid Reactor ◽  
Anaerobic Hybrid Reactor ◽  
Low Strength
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