Performance and stability of an expanded granular sludge bed reactor modified with zeolite addition subjected to step increases of organic loading rate (OLR) and to organic shock load (OSL)

2017 ◽  
Vol 77 (1) ◽  
pp. 39-50 ◽  
Author(s):  
T. Pérez-Pérez ◽  
I. Pereda-Reyes ◽  
E. Pozzi ◽  
D. Oliva-Merencio ◽  
M. Zaiat
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Stable Process ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Swine Wastewater ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Microbial Composition

Abstract This paper shows the effect of organic shock loads (OSLs) on the anaerobic digestion (AD) of synthetic swine wastewater using an expanded granular sludge bed (EGSB) reactor modified with zeolite. Two reactors (R1 and R2), each with an effective volume of 3.04 L, were operated for 180 days at a controlled temperature of 30 °C and hydraulic retention time of 12 h. In the case of R2, 120 g of zeolite was added. The reactors were operated with an up-flow velocity of 6 m/h. The evolution of pH, total Kjeldahl nitrogen, chemical oxygen demand (COD) and volatile fatty acids (VFAs) was monitored during the AD process with OSL and increases in the organic loading rate (OLR). In addition, the microbial composition and changes in the structure of the bacterial and archaeal communities were assessed. The principal results demonstrate that the presence of zeolite in an EGSB reactor provides a more stable process at higher OLRs and after applying OSL, based on both COD and VFA accumulation, which presented with significant differences compared to the control. Denaturing gradient gel electrophoresis band profiles indicated differences in the populations of Bacteria and Archaea between the R1 and R2 reactors, attributed to the presence of zeolite.

Treatment of Low-Strength Wastewater Using an Anaerobic Baffled Reactor at Low Temperature

2013 ◽  
Vol 325-326 ◽  
pp. 822-826
Author(s):  
Zong Lian She ◽  
Xiao Hui Fu ◽  
Jian Wu ◽  
En Shi ◽  
Lai Li Zhao ◽  
...  
Keyword(s):  
Low Temperature ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Granular Sludge ◽  
Organic Loading Rate ◽  
Scanning Electron Micrographs ◽  
Organic Loading ◽  
Microbial Composition ◽  
Anaerobic Baffled Reactor ◽  
Low Strength

Treatment of low-strength wastewater of chemical oxygen demand (COD) around 500-1500 mg/L was studied in a 100 L capacity laboratory scale anaerobic baffled reactor (four compartments) at low temperature (17 oC-25 oC). The reactor was operated at influent COD concentrations of 1500, 1000 and 500 mg/L and hydraulic retention times (HRTs) of 24, 12 and 8 h, with the average COD removals changing from 94% to 83%. Compartment-wise studies of various parameters revealed that if the organic loading rate (OLR) was larger, the initial compartment played significant role in the removal of organics. The examinations of scanning electron micrographs (SEM) indicated that the microbial composition of granular sludge were obviously different in four compartments.

Microbial community structure of activated sludge during aerobic granulation in an annular gap bioreactor

2006 ◽  
Vol 54 (1) ◽  
pp. 139-146 ◽  
Author(s):  
J.C. Williams ◽  
F.L. de los Reyes
Keyword(s):  
Loading Rate ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Annular Gap ◽  
Gradient Gel Electrophoresis ◽  
And Behavior ◽  
Cultivation Experiment

A novel annular gap reactor was designed to create a controlled shear environment in which aerobic granular sludge could be developed. The bacterial and eukaryal community structures during two aerobic granular sludge experiments were tracked using denaturing gradient gel electrophoresis (DGGE). The first granule cultivation experiment, using an organic loading rate of 1.6 kg/m3d COD, resulted in biomass that was dominated by filamentous bacteria and Zoogloea ramigera colonies. A second experiment with a higher organic loading rate of 6 kg/m3d COD developed a granule-like morphology but was ultimately dominated by filamentous fungi. Species identification via DGGE band purification and DNA sequencing closely matched the observed sludge morphology and behavior.

Performance of an anaerobic baffled reactor (ABR) as a hydrolysis-acidogenesis unit in treating landfill leachate mixed with municipal sewage

2000 ◽  
Vol 42 (12) ◽  
pp. 115-121 ◽  
Author(s):  
B. Wang ◽  
Y. Shen
Keyword(s):  
Landfill Leachate ◽  
Loading Rate ◽  
Granular Sludge ◽  
Operational Performance ◽  
Municipal Sewage ◽  
Organic Loading Rate ◽  
Stable Operation ◽  
Organic Loading ◽  
Anaerobic Baffled Reactor ◽  
Biological Treatability

A study on the performance of an Anaerobic Baffled Reactor(ABR) as a hydrolysis-acidogenesis unit in treating the mixed wastewater of landfill leachate and municipal sewage in different volumetric ratios was carried out. The results showed that ABR substantially improved the biological treatability of the mixed wastewater by increasing its BOD5/COD ratio to 0.4–0.6 from the initial values of 0.15–0.3. The formation of bar-shaped granular sludge of 0.5–5 mm both in diameter and length with an SVI of 7.5–14.2 ml/g was observed in all compartments of the ABR when the organic loading rate reached 4.71 kgCOD/m3 · d. The effects of the ratios of NH4+-N/COD and COD/TP in mixed wastewater on the operational performance were also studied, from which it was found that a reasonable NH4+-N/COD ratio should be lower than 0.02, and the phosphorus supplement was needed when the volumetric ratio was higher than 4:6 for stable operation of ABR.

scholarly journals The Concept of Wastes to Energy Using Sugary Wastes

2012 ◽  
Vol 9 ◽  
pp. 57-62
Author(s):  
Fiza Sarwar ◽  
Wajeeha Malik ◽  
Muhammad Salman Ahmed ◽  
Harja Shahid
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Sugar Mills ◽  
Anaerobic Sludge Blanket

Abstract: This study was designed using actual effluent from the sugary mills in an Up-flow Anaerobic Sludge Blanket (UASB) Reactor to evaluate treatability performance. The reactor was started-up in step-wise loading rates beginning from 0.05kg carbon oxygen demand (COD)/m3-day to 3.50kg-COD/m3-day. The hydraulic retention time (HRT) was slowly decreased from 96 hrs to eight hrs. It was observed that the removal efficiency of COD of more than 73% can be easily achieved at an HRT of more than 16 hours corresponding to an average organic loading rate (OLR) of 3.0kg-COD/m3-day, at neutral pH and constant temperature of 29°C. The average VFAs (volatile fatty acids) and biogas production was observed as 560mg/L and 1.6L/g-CODrem-d, respectively. The average methane composition was estimated as 62%. The results of this study suggest that the treatment of sugar mills effluent with the anaerobic technology seems to be more reliable, effective and economical.DOI: http://dx.doi.org/10.3126/hn.v9i0.7075 Hydro Nepal Vol.9 July 2011 57-62

Working Parameters Optimization of Hydrolysis-acidogenesis reactor in two stage anaerobic digestion of slaughterhouse Wastewater for Biogas Production

2020 ◽  
Author(s):  
Dejene Tsegaye Bedane ◽  
Mohammed Mazharuddin Khan ◽  
Seyoum Leta Asfaw
Keyword(s):  
Anaerobic Digestion ◽  
Working Conditions ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Slaughterhouse Wastewater ◽  
Working Parameters

Abstract Background : Wastewater from agro-industries such as slaughterhouse is typical organic wastewater with high value of biochemical oxygen demand, chemical oxygen demand, biological organic nutrients (Nitrogen and phosphate) which are insoluble, slowly biodegradable solids, pathogenic and non-pathogenic bacteria and viruses, parasite eggs. Moreover it contains high protein and putrefies fast leading to environmental pollution problem. This indicates that slaughterhouses are among the most environmental polluting agro-industries. Anaerobic digestion is a sequence of metabolic steps involving consortiums of several microbial populations to form a complex metabolic interaction network resulting in the conversation of organic matter into methane (CH 4 ), carbon dioxide (CO 2 ) and other trace compounds. Separation of the phase permits the optimization of the organic loading rate and HRT based on the requirements of the microbial consortiums of each phase. The purpose of this study was to optimize the working conditions for the hydrolytic - acidogenic stage in two step/phase anaerobic digestion of slaughterhouse wastewater. The setup of the laboratory scale reactor was established at Center for Environmental Science, College of Natural Science with a total volume of 40 liter (36 liter working volume and 4 liter gas space). The working parameters for hydrolytic - acidogenic stage were optimized for six hydraulic retention time 1-6 days and equivalent organic loading rate of 5366.43 – 894.41 mg COD/L day to evaluate the effect of the working parameters on the performance of hydrolytic – acidogenic reactor. Result : The finding revealed that hydraulic retention time of 3 day with organic loading rate of 1,788.81 mg COD/L day was a as an optimal working conditions for the parameters under study for the hydrolytic - acidogenic stage. The degree of hydrolysis and acidification were mainly influenced by lower hydraulic retention time (higher organic loading rate) and highest values recorded were 63.92 % at hydraulic retention time of 3 day and 53.26% at hydraulic retention time of 2 day respectively. Conclusion : The finding of the present study indicated that at steady state the concentration of soluble chemical oxygen demand and total volatile fatty acids increase as hydraulic retention time decreased or organic loading rate increased from 1 day hydraulic retention time to 3 day hydraulic retention time and decreases as hydraulic retention time increase from 4 to 6 day. The lowest concentration of NH 4 + -N and highest degree of acidification was also achieved at hydraulic retention time of 3 day. Therefore, it can be concluded that hydraulic retention time of 3 day/organic loading rate of 1,788.81 mg COD/L .day was selected as an optimal working condition for the high performance and stability during the two stage anaerobic digestion of slaughterhouse wastewater for the hydrolytic-acidogenic stage under mesophilic temperature range selected (37.5℃). Keywords : Slaughterhouse Wastewater, Hydrolytic – Acidogenic, Two Phase Anaerobic Digestion, Optimal Condition, Agro-processing wastewater

Aerobic granular sludge in an SBR-system treating wastewater rich in particulate matter

2004 ◽  
Vol 49 (11-12) ◽  
pp. 41-46 ◽  
Author(s):  
N. Schwarzenbeck ◽  
R. Erley ◽  
P.A. Wilderer
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Primary Particle ◽  
Loading Rate ◽  
Granular Sludge ◽  
Aerobic Granular Sludge ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Particle Uptake ◽  
Tracer Experiments

Aerobic granular sludge was successfully cultivated in a lab-scale SBR-system treating malting wastewater with a high content of particulate organic matter (0.9 gTSS/L). At an organic loading rate (CODtotal) of 3.4 kg/(m3·d) an average removal efficiency of 50% in CODtotal and 80% in CODdissolved was achieved. Fractionation of the COD by means of particle size showed that particles with a diameter less than 25–50 μm could be removed at 80% efficiency, whereas particles bigger than 50 μm were only removed at 40% efficiency. Tracer experiments revealed a dense sessile protozoa population covering the granules. The protozoa appeared to be responsible for primary particle uptake from the wastewater.

Impact of Hydraulic Retention Time at Constant Organic Loading Rate in a Two-Stage Expanded Granular Sludge Bed Reactor

2014 ◽  
Vol 31 (6) ◽  
pp. 317-323 ◽  
Author(s):  
Mahyar Ghorbanian ◽  
Robert M. Lupitskyy ◽  
Jagannadh V. Satyavolu ◽  
R. Eric Berson
Keyword(s):  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Granular Sludge ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Two Stage
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