scholarly journals A CRITICAL REVIEW ON THE EFFECT OF FEED TO INOCULUM RATIO ON BIOGAS DIGESTION

2021 ◽  
Vol 11 (2) ◽  
Author(s):  
M Kalyani ◽  
Shalini Suran ◽  
P Ramya
Keyword(s):  
Particle Size ◽  
Municipal Wastewater ◽  
Loading Rate ◽  
Synergistic Effects ◽  
Considerable Effect ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Successful Operation ◽  
Start Up ◽  
Biogas Digestion

This paper primarily focuses on the effect of feed to inoculum ratio on biogas digestion; and outlines the various feeds, inoculums, and synergistic effects of the combination of inoculums by referring to the literature. The Start-up of an anaerobic digestion system is highly critical and pivotal for the successful operation of an anaerobic digester. For this purpose, a certain amount of inoculum is added to the digester along with the substrate to provide the necessary microorganisms to initiate the digestion process. The ratio and the type of inoculum used substantially affect the rate of biodegradation and the lag time. The degradation of substrate depends on the concentration of microorganisms. When food waste was considered as the feed it was found that factors such as waste oil content, the addition of alkaline buffer, particle size, organic loading rate had a considerable effect on the feed to inoculum ratio. Studies considering some other feeds such as animal by products from piggery slaughterhouses, poultry slaughterhouse wastes, agro-industrial waste, anaerobically digested sludge obtained from municipal wastewater, and dewatered digestate cake were also compared. Hence, the objective of this study is to offer an integrated view of the appropriate feed and the inoculum under the effect of various other essential parameters. The major performance indicators from this study were found to be particle size of inoculum, organic loading rate, the addition of alkaline buffer, F/I ratio, and structure of inoculum

Anaerobic Treatment of Polyethylene Terephthalate (PET) Wastewater from Lab to Full Scale

1999 ◽  
Vol 40 (8) ◽  
pp. 229-236 ◽  
Author(s):  
F. Fdz-Polanco ◽  
M. D. Hidalgo ◽  
M. Fdz-Polanco ◽  
P. A. García Encina
Keyword(s):  
Polyethylene Terephthalate ◽  
Loading Rate ◽  
Treatment Plant ◽  
Textile Wastewater ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Organic Loading Rate ◽  
Foam Formation ◽  
Organic Loading ◽  
Start Up

In the last decade Polyethylene Terephthalate (PET) production is growing. The wastewater of the “Catalana de Polimers” factory in Barcelona (Spain) has two main streams of similar flow rate, esterification (COD=30,000 mg/l) and textile (COD=4000 mg/l). In order to assess the anaerobic treatment viability, discontinuous and continuous experiments were carried out. Discontinuous biodegradability tests indicated that anaerobic biodegradability was 90 and 75% for esterification and textile wastewater. The textile stream revealed some tendency to foam formation and inhibitory effects. Nutrients, micronutrients and alkali limitations and dosage were determined. A continuous lab-scale UASB reactor was able to treat a mixture of 50% (v) esterification/textile wastewater with stable behaviour at organic loading rate larger than 12 g COD/l.d (0.3 g COD/g VSS.d) with COD removal efficiency greater than 90%. The start-up period was very short and the recuperation after overloading accidents was quite fast, in spite of the wash-out of solids. From the laboratory information an industrial treatment plant was designed and built, during the start-up period COD removal efficiencies larger than 90% and organic loading rate of 0.6 kg COD/kg VSS.d (5 kg COD/m3.d) have been reached.

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.

Start-Up Strategy to Achieve Excellent Efficiency of Degradation Acetate,Ethanol and Propionate in UASB

2011 ◽  
Vol 71-78 ◽  
pp. 2103-2106
Author(s):  
Ming Yue Zheng ◽  
Ming Xia Zheng ◽  
Kai Jun Wang ◽  
Hai Yan
Keyword(s):  
Loading Rate ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Metabolic Intermediate ◽  
Loading Rates ◽  
Start Up ◽  
Anaerobic Sludge Blanket

The performance of upflow anaerobic sludge blanket (UASB) fed with three metabolic intermediate (acetate, ethanol, and propionate) respectively was studied. The degradation of metabolic intermediate were investigated to discuss the reason for propionate inhibition problem in anaerobic treatment. The hydraulic retention time (HRT) in the reactors started with 8.0h.The yield rate of biogas were 237ml/gCOD, 242ml/gCOD, 218ml/gCOD for acetate, ethanol and propionate, respectively when finishing start-up under OLR of 5.0 kgCOD/(m3·d) (HRT=9.6h).The HRT remained constant 9.6h,and the substrate concentration was gradually increased from 1,000 to 16,000mg/L as COD,and the organic loading rates(OLR) was from 3.0 to 40.0 kgCOD/(m3·d).The maximum propionate concentration was 41.6 gHPr-COD/L at the organic loading rate of 43.9 kgCOD/(m3·d) (HRT, 9.6h) as well as acetate and ethanol.

Kinetics of an anaerobic fluidized bed reactor using biolite carrier

1996 ◽  
Vol 23 (6) ◽  
pp. 1305-1315 ◽  
Author(s):  
R. Prakash ◽  
K. J. Kennedy
Keyword(s):  
Steady State ◽  
Fluidized Bed ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Loading Rates ◽  
Start Up ◽  
Removal Efficiencies ◽  
Biofilm Development ◽  
Kinetics Of

Start-up and steady state operation of anaerobic fluidized bed reactors (AFBRs) with biolite as the inert carrier material was studied. Start-up and concomitant biofilm development of AFBRs was performed using two common start-up techniques, the maximum efficiency profile (MEP) technique and the maximum load profile (MLP) technique. The MEP start-up technique increases the volumetric organic loading rates to the reactor gradually and is tied to the removal efficiency of the process. The MLP start-up technique maintains a moderately high but constant volumetric organic loading rate irrespective of reactor performance. Using sucrose-based wastewater as feed, both start-up techniques led to equally fast biofilm development and start-up times of approximately 5 weeks. However, the MEP technique resulted in more stable controlled reactor operation during the start-up period. The quick start-up confirms the high compatibility of biolite for bio-adhesion and the development of a healthy active biofilm.High concentrations of biofilm biomass achieved in AFBRs (69 g volatile biofilm solids (VBS)/L of expanded bed volume at an organic loading rate of 25 g COD/(Lùd)) allowed the successful treatment of wastewaters at high organic loading rates and organic removal efficiencies. During steady state experiments, organic removal efficiencies over 80% were obtained for organic loading rates as high as 20 g COD/(L∙d). It was found that the dependence of removal efficiency on hydraulic retention time is influenced by substrate concentration. Total biofilm yield was determined to be 0.08 g VBS/g COD removed, demonstrating the low net synthesis of solids in the AFBR. AFBRs had an average solids retention time of 150 days, corresponding to a washout factor of 0.01. Extrinsic kinetics of the AFBRs was determined to be zero order with a maximum specific utilization rate of 0.48 g COD/(g VBS∙d).AFBRs used to treat municipal landfill leachate with a BOD5:COD ratio of 0.86 achieved steady state COD removal efficiencies that ranged from 70% to 87%, depending on the reactor organic loading rate and the concentration of the leachate being treated. During leachate treatment, biofilm biomass gradually became "mineralized" as a result of precipitation of metal sulfides and carbonates. This eventually resulted in a decrease in biofilm microbial activity and the need for higher pumping rates to maintain the same degree of bed expansion. Key words: anaerobic, biological fluidized bed reactor, biolite, landfill leachate, sucrose, modeling, start-up, steady state kinetics.

Co-digestion of microalga-bacteria biomass with papaya waste for methane production

2018 ◽  
Vol 78 (1) ◽  
pp. 125-131 ◽  
Author(s):  
Glenda Cea-Barcia ◽  
Jaime Pérez ◽  
Germán Buitrón
Keyword(s):  
Enzymatic Activity ◽  
Municipal Wastewater ◽  
Loading Rate ◽  
High Rate ◽  
Methane Yield ◽  
Organic Loading Rate ◽  
Ammonium Concentration ◽  
Volatile Solid ◽  
Organic Loading ◽  
Total Volatile

Abstract The anaerobic co-digestion of microalga-bacteria biomass and papaya waste (MAB/PW) was evaluated under semi-continuous conditions. Microalgae-bacteria biomass was obtained from a high rate algal pond fed with municipal wastewater and artificially illuminated. The co-digestion of MAB/PW was evaluated using a 1:1 (w/w) ratio and an organic loading rate of 1.1 ± 0.1 g COD/L/d. Enzymatic activity assays of papain were performed in the feeding to determine the activity of this enzyme in the substrate mixture. A methane yield of 0.55 L CH4/gVS and 68% of total volatile solid removal were observed. The volumetric productivity was 0.30 ± 0.03 L CH4/L/d with a methane content of 71%. It was observed that papaya waste was a suitable co-substrate because it maintained a low ammonium concentration, decreasing the risk of inhibition due to ammonia and then increasing the methane yield of the microalgae-bacteria biomass compared to the biomass alone. The pretreatment effect by the addition of papaya waste on the microalgae-bacteria biomass was supported by the papain activity remaining in the substrate.

Start-up of anaerobic fixed film reactors: technical aspects

1994 ◽  
Vol 29 (10-11) ◽  
pp. 297-308 ◽  
Author(s):  
U. Austermann-Haun ◽  
C. F. Seyfried ◽  
G. Zellner ◽  
H. Diekmann
Keyword(s):  
Municipal Wastewater ◽  
Loading Rate ◽  
Starter Culture ◽  
Treatment Plant ◽  
Organic Loading Rate ◽  
Municipal Wastewater Treatment ◽  
Start Up ◽  
Effluent Recirculation ◽  
Fixed Film ◽  
Start Ups

For two years lab-scale experiments were done to find the conditions to enhance the start-up of anaerobic fixed film reactors. Five reactors were operated in parallel with a sythetic wastewater containing acetic, propionic and butyric acid in a weight relation of 2:1:1 resulting in a COD of 20,000 mg/l. Using polypropylene curlers (NOR-PAC R 92/1) as support medium (substratum) and mostly digested sludge of a municipal wastewater treatment plant as inoculum, we found that the activity of the starter culture, effluent recirculation, calcium dosage and the mode of increasing the organic loading rate had a significant influence on start-up behaviour. Depending on the way to run the start-up space loading rates of 10 to 30 g COD/(l·d) could be reached within 58 days. In contrast to these “manual” start-ups it is shown that the most efficient way is to run a start-up pH-statically with an automatic substrate feeding regulated by the pH measured in the top of the reactor. Within 36 days a space loading rate of 60 g COD/(l·d) with a COD removal efficiency of 70 % could be reached.

Start-up of full-scale anaerobic digesters treating municipal solid waste

2003 ◽  
Vol 48 (4) ◽  
pp. 249-252 ◽  
Author(s):  
T. Ohmura ◽  
T. Sakai ◽  
Y. Shindo ◽  
K. Nakamura ◽  
T. Ike ◽  
...  
Keyword(s):  
Loading Rate ◽  
Gas Production ◽  
Full Scale ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Methane Fermentation ◽  
Start Up ◽  
Direct Technique ◽  
Short Period ◽  
Sludge Recycling

Raising organic loading rate, and the behavior of dissolved CODcr (D-CODcr), VFA and specific methanogen activity, were investigated through a laboratory experiment for the start-up of a sludge recycling center. Moreover, application for MPN-PCR methods using a gene as a direct technique to measure the quantity of methanogen was attempted. It was recognized that specific methanogen activity depends on the quantity of methanogen, and that gas production does not reflect the condition of methane fermentation. The methane fermentation condition was checked through the specific methanogen activity and analysis of D-CODcr. The target organic loading rate was reached in the short period of about 30 days, and rapid start-up was successfully attained for a full-scale anaerobic digester.

Start up of an anaerobic inverse turbulent bed reactor fed with wine distillery wastewater using pre-colonised bioparticles

2005 ◽  
Vol 51 (1) ◽  
pp. 153-158 ◽  
Author(s):  
C. Arnaiz ◽  
S. Elmaleh ◽  
J. Lebrato ◽  
R. Moletta
Keyword(s):  
Industrial Wastewater ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Biofilm Reactors ◽  
Start Up ◽  
Distillery Wastewater

The long start-up period of fluidized bed biofilm reactors is a serious obstacle for their wide installation in the anaerobic treatment of industrial wastewater. This paper presents the results of an anaerobic inverse turbulent bioreactor treating distillery wastewater during 117 days of operation at a laboratory scale. The pre-colonized bioparticles for this work were obtained from a similar reactor processing the same wastewater and which had a start-up period of 3 months. The system attained carbon removal efficiency rates between 70 and 92%, at an organic loading rate of 30.6 kg m+3 d+1 (chemical oxygen demand) with a hydraulic retention time of 11.1 h. The results obtained showed that the start-up period of this kind of reactors can be reduced by 3 using pre-colonized bioparticles.

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