scholarly journals Impact of Temperature on the Performance and Character of the Methanogenic Community of a Fixed-Bed Anaerobic Reactor at Psychrophilic Temperature

Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3051
Author(s):  
Hongyan Zhao ◽  
Hongdou Liu ◽  
Yu Sun ◽  
Liqiang Zhang ◽  
Ullah Fazl ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Biogas Production ◽  
Removal Rate ◽  
Fixed Bed ◽  
Rrna Gene ◽  
Temperature Threshold ◽  
Reactor Performance ◽  
Fixed Bed Reactors ◽  
Biofilm Carrier ◽  
Cod Removal Rate

To determine the effects of a gradual temperature decrease on reactor performance and the microbial community, four fixed-bed reactors that were packed with a biofilm carrier were operated for 217 days. The temperature of the reactors was decreased from 30 °C to 3 °C. The reactors initially soured at 3 °C and recovered when they were returned to 4 °C, as indicated by the stabilization of biogas production, methane production, VFA concentration, pH, and the COD removal rate. Our results also revealed that methanomicrobiales were the dominant methanogen, the concentration of the 16S rRNA gene in the carbon-fiber carrier sludge exceeded the same gene concentration in the deposited sludge, and that the carbon-fiber carrier played an important role in methanomicrobiale colonization at low temperatures. We suggest that 4 °C is the low-temperature threshold for optimal reactor performance.

scholarly journals Impact of Organic Loading Rate on Performance and Methanogenic Microbial Communities of a Fixed-Bed Anaerobic Reactor at 4 °C

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2586
Author(s):  
Hongyan Zhao ◽  
Feifan Yan ◽  
Xue Li ◽  
Renzhe Piao ◽  
Weidong Wang ◽  
...  
Keyword(s):  
Acid Content ◽  
Loading Rate ◽  
Biogas Production ◽  
Removal Rate ◽  
Fixed Bed ◽  
Organic Loading Rate ◽  
Rrna Gene ◽  
Organic Loading ◽  
16S Rrna Gene Analysis ◽  
Anaerobic Reactor

We investigated the feasibility of producing biogas in a fixed-bed anaerobic reactor at 4 °C with a gradual increase in organic loading rate (OLR). Reactor efficiency was highest when OLR was 4.33 kg/m3·d, whereas the reactor acidification occurred when OLR was 4.67 kg/m3·d. The values of methane content, biogas production, chemical oxygen demand (COD) removal rate, biogas production rate, acetic acid content, and propionic acid content were 69.3%, 5.33 L, 59.8%, 1.03 L/OLR, 0.17 g/L, and 1.15 g/L, respectively. The pH was stable and ranged from 7.2 to 6.8 when the reactor was operating at 4 °C during OLR increase. The 16S rRNA gene analysis revealed that the dominant archaea were Methanosaetaceae at 30 °C. At 4 °C, the dominant archaea were Methanomicrobiales, which were more abundant in adhering sludge compared to settled sludge. In conclusion, operating a fixed-bed anaerobic reactor at psychrophilic temperatures is more suitable.

Application of Biofilm Kinetics to Anaerobic Fixed Bed Reactors

1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal
Keyword(s):  
Removal Rate ◽  
Fixed Bed ◽  
Experimental Studies ◽  
Pilot Scale ◽  
Cod Removal ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Removal Mechanism ◽  
Term Operation ◽  
Fixed Bed Reactors

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.

Research on Treatment of Domestic Sewage with Aerobic Denitrifying Bacteria Immobilized by Carbon Fiber

2014 ◽  
Vol 675-677 ◽  
pp. 627-632 ◽  
Author(s):  
Qun Wei ◽  
Di Lv ◽  
Mei Hui Huang ◽  
De Shui Yu ◽  
Jian Qiang You
Keyword(s):  
Nitric Acid ◽  
Carbon Fiber ◽  
Removal Rate ◽  
Denitrifying Bacteria ◽  
Ammonia Nitrogen ◽  
Domestic Sewage ◽  
Treated Wastewater ◽  
Adsorption Method ◽  
Concentrated Sulfuric Acid ◽  
Cod Removal Rate

Aerobic denitrifying bacteria, a fast and efficient strain, is extensively adopted in the wastewater sphere, and immobilized aerobic denitrifying bacteria denitrification Technology, to some extent, solves many problems existing in the direct application of aerobic denitrifying bacteria. Concentrated sulfuric acid, nitric acid, potassium permanganate, ferric chloride etc. are used to pretreat carbon fiber respectively, and then the modified the carbon fiber is applied to fix the activated aerobic denitrifying bacteria to investigate the effects of the modification of the carbon fiber and the effects of wastewater treatment with immobilized aerobic denitrifying bacteria. The results showed that the fixed efficiency of the strain with carbon fiber pretreated by nitric acid reached 50% and when the strain fixed by the modified carbon fiber in adsorption method treated wastewater, the ammonia nitrogen removal rate reached 78% and the COD removal rate was always stabilized above 40% in three days.

scholarly journals Cassava Wastewater Treatment in Fixed-Bed Reactors: Organic Matter Removal and Biogas Production

2019 ◽  
Vol 3 ◽  
Author(s):  
Elisangela Watthier ◽  
Cristiane L. Andreani ◽  
Douglas G. B. Torres ◽  
Osvaldo Kuczman ◽  
Maria H. F. Tavares ◽  
...  
Keyword(s):  
Organic Matter ◽  
Wastewater Treatment ◽  
Biogas Production ◽  
Fixed Bed ◽  
Organic Matter Removal ◽  
Fixed Bed Reactors ◽  
Cassava Wastewater

Hybrid reactor performance in pentachlorophenol (pcp) removal by anaerobic granules

2001 ◽  
Vol 44 (4) ◽  
pp. 137-144 ◽  
Author(s):  
M. De Almeida Prado Montenegro ◽  
E. De Mattos Moraes ◽  
H. Moreira Soares ◽  
R. Filomena Vazoller
Keyword(s):  
Fatty Acids ◽  
Volatile Fatty Acids ◽  
Culture Media ◽  
Biogas Production ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Concentration Addition ◽  
Hybrid Reactor ◽  
Reactor Performance

The present research aimed at evaluating pentachlorophenol (PCP) degradation in a hybrid reactor supplied with a mixture of fatty acids (propionic, butyric, acetic and lactic) and methanol. The performance of the reactor is remarkably stable and efficient during PCP additions at range of 2.0 to 21.0 mg/L. The reduction of chemical oxygen demand (COD) was around 97% and methane was found to be 86% in the biogas production. The efficiency of volatile fatty acids breakdown was 93%, 64% and 74% respectively for butyric, propionic and acetic. PCP total removal of more than 99% was reached by granular sludge activities formed during 21 months of reactor operation. Methanogenic microorganisms predominance was noticed with 105 to 106 cells/mL during enumeration on methanol or lactate added to sulfate culture media. The removal rate was 1.07 mg PCP · g−1 VS · d−1 during the highest PCP concentration addition.

Anaerobic ammonium oxidation of ammonium-rich waste streams in fixed-bed reactors

2004 ◽  
Vol 49 (11-12) ◽  
pp. 77-82 ◽  
Author(s):  
C. Fux ◽  
V. Marchesi ◽  
I. Brunner ◽  
H. Siegrist
Keyword(s):  
Removal Rate ◽  
Elimination Rate ◽  
Fixed Bed ◽  
Treatment Plant ◽  
Experimental Period ◽  
Anaerobic Ammonium Oxidation ◽  
Synthetic Wastewater ◽  
Ammonium Oxidation ◽  
Fixed Bed Reactors ◽  
Anammox Activity

The feasibility of anaerobic ammonium oxidation (Anammox) in fixed-bed reactors was evaluated on laboratory and pilot scales. Using synthetic wastewater, the specific nitrogen removal rate was increased from 0.05-0.1 kgNm-3reactord-1 to 0.35-0.38 kgNm-3reactord-1 within a year (T = 22-27°C) in all applications. However, the anammox activity was seriously and repeatedly inhibited at prolonged high nitrite concentrations (e.g. six days at 30-50 gNO2-Nm-3) and recovery was always a lengthy process. But even at a moderate nitrite concentration (11 ± 10 gNO2-Nm-3), the observed specific growth rate was only 0.018 d-1 at 26.4 ± 0.8°C, which corresponds to approximately 0.025 d-1 at 30°C (doubling time: 28 days). In a second experimental period for another 250 days, one of the laboratory reactors was fed with partially nitrified sludge liquors from a domestic wastewater treatment plant (WWTP). In this case, the specific elimination rate was as high as 3.5 kgNm-3reactord-1 at 26-27°C. Independently of the feed, the average nitrogen elimination rate lay between 80-85% in all applications. An appropriate hydraulic design is essential to prevent clogging and local nitrite inhibition in fixed-bed reactors.

scholarly journals Assessment of Multiple Anaerobic Co-Digestions and Related Microbial Community of Molasses with Rice-Alcohol Wastewater

Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4866 ◽  
Author(s):  
Sohail Khan ◽  
Fuzhi Lu ◽  
Qiong Jiang ◽  
Chengjian Jiang ◽  
Muhammad Kashif ◽  
...  
Keyword(s):  
Microbial Communities ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Removal Rate ◽  
Cod Removal ◽  
Ion Concentration ◽  
Organic Loading Rate ◽  
Digestion Process ◽  
Cod Removal Rate ◽  
Archaeal Communities

Molasses is a highly dense and refined byproduct produced in the sugarcane industry, and it contains high amounts of degradable compounds. Through bioconversion, these compounds can be transformed into renewable products. However, the involved biological process is negatively influenced by the high chemical oxygen demand (COD) of molasses and ion concentration. The co-digestion of molasses with rice-alcohol wastewater (RAW) was compared with its mono-digestion at an increasing organic loading rate (OLR). Both processes were assessed by detecting the COD removal rate, the methane contents of biogas, and the structure and composition of microbial communities at different stages. Results showed that the co-digestion is stable up to a maximum OLR of 16 g COD L−1 d−1, whereas after the acclimatization phase, the mono-digestion process was disturbed two times, which occurred at a maximum OLR of 9 and 10 g COD L−1 d−1. The volatile fatty acids (VFAs) observed were 2059.66 mg/L and 1896.9 mg/L, which in mono-digestion causes the inhibition at maximum OLRs. In the co-digestion process, the concomitant COD removal rates and methane content recorded was 90.72 ± 0.63% 64.47% ± 0.59% correspondingly. While in the mono-digestion process, high COD removal rate and methane contents observed were 89.29 ± 0.094% and 61.37 ± 1.06% respectively. From the analysis of microbial communities, it has been observed that both the bacterial and archaeal communities respond differently at unlike stages. However, in both processes, Propionibacteriaceae was the most abundant family in the bacterial communities, whereas Methanosaetaceae was abundant in the archaeal communities. From the current study, it has been concluded that that rice-alcohol wastewater could be a good co-substrate for the anaerobic digestion of molasses in terms of COD removal rate and methane contents production, that could integrate molasses into progressive biogas production with high OLR.

Microbiology and chemical engineering-new possibilities for interdisciplinary cooperation in the development of small anaerobic wastewater treatment plants

2000 ◽  
Vol 41 (1) ◽  
pp. 17-20 ◽  
Author(s):  
M. Kozariszczuk ◽  
W. Wenzel ◽  
M. Kraume ◽  
U. Szewzyk
Keyword(s):  
Waste Water ◽  
Chemical Engineering ◽  
Wastewater Treatment Plants ◽  
Waste Water Treatment ◽  
Fixed Bed ◽  
Interdisciplinary Cooperation ◽  
Reactor Performance ◽  
Fixed Bed Reactors ◽  
Microbiological Methods ◽  
Microbiological Parameters

Anaerobic degradation of waste water in fixed bed reactors is investigated using molasses as an example of complex composed waste water. The results of differently sized rectors are shown to be transferable and can be used for the design of small waste water treatment plants. The assessment of the reactor performance is done not only by material balances but also by applying microbiological parameters. Modern microbiological methods enable the incorporation of biological parameters into reactor design and process control. The results of these measurements lead to a better understanding of the correlation between changing process parameters and the state of the microbial population. Thus new tools are available to maintain stable and save anaerobic processes.

Activated carbon fiber filler in aerated bioreactor for industrial wastewater treatment

2012 ◽  
Vol 65 (10) ◽  
pp. 1753-1758 ◽  
Author(s):  
Dongkai Zhou ◽  
Reti Hai ◽  
Wenxing Wang ◽  
Donglin Zhao ◽  
Shuo Wang
Keyword(s):  
Wastewater Treatment ◽  
Activated Carbon ◽  
Carbon Fiber ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Activated Carbon Fiber ◽  
Wastewater Disposal ◽  
Biocompatibility Test ◽  
Cod Removal Rate ◽  
High Chemical Oxygen Demand

The aerated bioreactor is a promising technology for wastewater treatment. Activated carbon fiber (ACF) used as a biomembrane carrier in wastewater disposal has attracted much more concern recently. The high modulus polyacrylonitrile (PAN)-based ACF was successfully used as a biomembrane carrier for hard-to-biodegrade industrial organic wastewater disposal in a lab-scale aerated biomembrane reactor at room temperature. The biocompatibility test shows that the biomembrane grows quickly on the ACF filler (ACFF) surface; bacteria and microzoon can breed on the ACFF surface at high chemical oxygen demand (COD) concentration. The COD removal rate tests show that the ACFF bioreactor has high capability to remove COD.

Tertiary Nitrification Pilot Plants on Parisian Waste Water

1990 ◽  
Vol 22 (1-2) ◽  
pp. 347-352 ◽  
Author(s):  
C. Paffoni ◽  
B. Védry ◽  
M. Gousailles
Keyword(s):  
Waste Water ◽  
Metropolitan Area ◽  
Fixed Bed ◽  
Point Of View ◽  
Operating Conditions ◽  
Research Center ◽  
Daily Output ◽  
Practical Point ◽  
Fixed Bed Reactors

The Paris Metropolitan area, which contains over eight million inhabitants, has a daily output of about 3 M cu.meters of wastewater, the purification of which is achieved by SIAAP (Paris Metropolitan Area Sewage Service) in both Achères and Valenton plants. The carbon pollution is eliminated from over 2 M cu.m/day at Achères. In order to improve the quality of output water, its tertiary nitrification in fixed-bed reactors has been contemplated. The BIOFOR (Degremont) and BIOCARBONE (OTV) processes could be tested in semi-industrial pilot reactors at the CRITER research center of SIAAP. At a reference temperature of 13°C, the removed load is approximately 0.5 kg N NH4/m3.day. From a practical point of view, it may be asserted that in such operating conditions as should be at the Achères plant, one cubic meter of filter can handle the tertiary nitification of one cubic meter of purified water per hour at an effluent temperature of 13°C.

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