scholarly journals Optimum Organic Loading Rate in the Biomethanation of a Mixture of Cow Dungs and Poultry Droppings

2020 ◽  
Vol 2 (2) ◽  
pp. 1-5
Author(s):  
Julius Olatunji Jeje ◽  
Oluwaseun Ruth Alo ◽  
Tomiwa Oke Akadiri
Keyword(s):  
Carbon Dioxide ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Cow Dung ◽  
Organic Loading ◽  
Maximum Volume ◽  
Loading Rates ◽  
Poultry Droppings ◽  
Sludge Concentration

The effect of varying the organic loading rate in the digester volume using a mixture of poultry droppings and cow dung as biomass was studied. The study was aimed at determining the optimum organic loading rates, which would produce the maximum volume of biogas from a mixture of poultry droppings and cow dung. The pH was maintained between 6.8 and 7.2. All other parameters affecting the production of gas were kept constant except the organic loading rate. The wastes, poultry droppings and cow dung was mixed in the ratio 60:40 and maintained at a sludge concentration of 700g/l. It was observed that biogas produced from the digester with the organic loading rate of 2.8 kg vs/m3/day gives the highest proportion of methane and the digester with organic loading rate of 3.2 kg vs/m3/day produced the highest proportion of carbon dioxide.

Effect of Organic Loading Rate (OLR) on Biogas Yield Using a Single and Three-Stages Continuous Anaerobic Digestion Reactors

2018 ◽  
Vol 39 ◽  
pp. 147-155 ◽  
Author(s):  
Ejiroghene Kelly Orhorhoro ◽  
Patrick Okechukwu Ebunilo ◽  
Godwin Ejuvwedia Sadjere
Keyword(s):  
Waste Water ◽  
Loading Rate ◽  
Single Stage ◽  
Organic Loading Rate ◽  
Cow Dung ◽  
Organic Loading ◽  
Continuous Increase ◽  
Biogas Yield ◽  
Load Rate ◽  
Three Stages

The rate at which feedstock is added to the anaerobic digester (AD) reactor has to be adjusted for the growth rate of methanogens bacteria. Increase in biogas yield is as a result of improved mathanogens forming bacteria. Under loading and over loading of feedstock in the AD reactor has effect on methanogens forming bacteria. If more feedstock is added than the bacteria are able to degrade, the process will become acidic. Feedstock has to been fed to the reactor at a uniform rate and volume. If feeding pattern has to change, this must be done gradually so that bacteria can adapt to the new conditions. For optimum biogas yield, required amount of feedstock must be added to the AD reactor. The aim of this research work is to determine the effect of organic loading rate (OLR) on biogas yield from food waste, water hyacinth, cow dung, waste water from abattoir, poultry dropping and pig dung. The experimental set up comprises of single stage and three-stage continuous AD reactors. The same quantity and composition of feedstock were used and this was subjected to a variation of OLR 0.5 kg/m3(1.5 kg/m3, 2 kg/m3, 2.5 kg/m3, and 3 kg/m3). The experiment was conducted within a mesophilic temperature range of 36°C-37°C, percentage total solid (%TS) of 9.98% and percentage volatile solid (%VS) of 78%. pH meter was used to monitored the daily pH reading of the slurry. It was observed that the quantity of biogas yield from the feedstock increases with increasing organic load rate to the optimum value of 1.5 kg/m3and started decreasing above the optimum value for a single stage AD reactor but this was not the case for the three-stages continuous AD reactors that experienced continuous increase in biogas yield with a successive increase in OLR from 1-5 kg/m3-3.0 kg/m3.

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.

Treatment of Landfill Leachate with an Upflow Anaerobic Reactor Combining a Sludge Bed and a Filter

1989 ◽  
Vol 21 (4-5) ◽  
pp. 133-143 ◽  
Author(s):  
Juu-En Chang
Keyword(s):  
Landfill Leachate ◽  
Energy Recovery ◽  
Conversion Factor ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Efficient Treatment ◽  
Loading Rates ◽  
Operational Characteristics

The operational characteristics, efficiency of treatment of landfill leachate, and recovery of energy in a laboratory scale hybrid bioreactor were investigated. The reactor was a continuous upflow system combining a sludge bed and a filter and was operated at 35°C. This modified anaerobic sludge bed filter (SBF) reactor was found to provide efficient treatment of the organic constituents of the leachate. Removal of soluble COD was greater than 92% at organic loading rates less than 13 kg COD/m3/d, and removal decreased to 70% with an organic loading rate of 21.77 kg COD/m3/d. A solids balance indicated that 0.041 g volatile suspended solids (VSS) were produced per gram of COD removed. The removal of sulfate and soluble Fe was as high as 90% and 96.9%, respectively. An accumulation of Fe was observed. When the influent concentration of total Fe ranged from 160 to 515 mg/l, the total Fe concentration in the sludge was as high as 7,100 mg/l after a 185 day period of operation. The sulfate loading of the system affected energy recovery. When the sulfate loading rate increased from 102 to 683 mg/l/d, energy recovery decreased from 90% to 52%. The biogas conversion factor for methane was 0.31 1 at STP per gram of COD removed.

Overcoming barriers to codigestion

2016 ◽  
Vol 11 (2) ◽  
pp. 413-422 ◽  
Author(s):  
D. L. Parry ◽  
L. Fillmore
Keyword(s):  
Organic Waste ◽  
Loading Rate ◽  
Biogas Production ◽  
Economic Impacts ◽  
Organic Wastes ◽  
Wastewater Sludge ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Widespread Application ◽  
Loading Rates

Codigestion of organic waste with municipal wastewater sludge is growing rapidly. It has many benefits, including diversion of organic waste from landfills, increased renewable energy from biogas production, and potential for revenue from tipping fees. However, there are still barriers to greater widespread application of codigestion. Economics, need for collaboration between utilities, impacts on wastewater application, unsupportive regulations and risks to core wastewater treatment business are obstacles that slow wider adoption of codigestion throughout the world. The research presented analyzes the economic impacts of codigestion, predicts the additional biogas production, and determines the allowable organic loading rate and fats oils and grease (FOG) addition for stable digestion operation. The economic impacts were analyzed on a life cycle cost basis and presented in terms of required tipping fees for different organic wastes, electric rates and residuals handling costs. Standard biochemical methane potential tests were conducted to estimate biogas production from various organic wastes. The specific energy loading rate (SELR) was used to express the allowable organic loading rate. Results from the economic analysis showed that codigestion using existing digesters at a municipal water reclamation facility is more economical than building new digesters. Codigestion was more economical at facilities with high electricity costs and low cost of residuals. Tipping fees for receiving organic waste would be required to offset the net cost of codigestion for wastes other than FOG. There was a net positive economic benefit of receiving FOG without a tipping fee. The upper limit of FOG for stable digestion was found to be 60 percent of the feed by chemical oxygen demand (COD). Stable digestion can be achieved with an SELR of less than 0.25 kgCOD/day/kgVS. The SELR accounts for the strength or energy content of the organic feed measured in COD. It was observed and accounted for by the SELR that anaerobic digesters loaded at higher solids concentrations (resulting in greater inventory of microorganisms in the digesters) can be fed at higher loading rates. Insights into the economics of codigestion and allowable organic loading rates for high strength organic wastes help to overcome some of the barriers to widespread application of codigestion.

Effect of Organic Loading Rate (OLR) of Slurry on Biogas Production Quality

2015 ◽  
Vol 1115 ◽  
pp. 325-330
Author(s):  
Maizirwan Mel ◽  
Nadiah Mohd Suhuli ◽  
Avicenna ◽  
Sany Izan Ihsan ◽  
Ahmad Faris Ismail ◽  
...  
Keyword(s):  
Loading Rate ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Continuous System ◽  
Total Solid ◽  
Organic Loading Rate ◽  
Cow Dung ◽  
Feeding Rates ◽  
Organic Loading ◽  
Biogas Yield

In this study, three different concentration of organic loading rate (OLR) were investigated to examine the effect of the change in the organic loading rate on the efficiency of the biogas production. Daily amount of biogas of different type of organic loading rate (OLR), rates of production of biogas, removal efficiencies of chemical oxygen demand (COD), total solid (TS) matter, volatile solids (VS) matter from the slurry were investigated in 30 days retention tyme using 50 L digester. The digester was operated at different organic feeding rates of 25000 mg/L COD, 50000 mg/L COD, and 75000 mg/L COD. The material used in this system is the fruits waste, vegetables waste and cow dung. The system operated in continuous system. The reactor showed stable performance with the highest quality of methane (concentration about70.3% of CH4) and rate of biogas production is 38.1 L/day with COD reduction of 52.1% during organic loading rate 50000 mg/L COD. As the organic loading rate was increased, the COD degradation and biogas yield decreased. Based on this result, the OLR of 50000 mg/L COD is suggested as design criteria for pilot biogas production.

Effect of the addition of fatty by-products from the refining of vegetable oil on methane production in co-digestion

2012 ◽  
Vol 66 (10) ◽  
pp. 2237-2242 ◽  
Author(s):  
M. Torrijos ◽  
P. Sousbie ◽  
L. Badey ◽  
F. Bosque ◽  
J. P. Steyer
Keyword(s):  
Vegetable Oil ◽  
Methane Production ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Cow Dung ◽  
Vegetable Waste ◽  
Organic Loading ◽  
Fruit And Vegetable ◽  
Volatile Solids ◽  
By Products

The purpose of this work was to investigate the effects of the addition of by-products from the refining of vegetable oil on the behavior of co-digestion reactors treating a mixture of grass, cow dung and fruit and vegetable waste. Three by-products were used: one soapstock, one used winterization earth and one skimming of aeroflotation of the effluents. Three 15 l reactors were run in parallel and fed five times a week. In a first phase of 4 weeks, the three reactors were fed with the co-digestion substrates alone (grass, cow dung and fruit and vegetable waste) at an organic loading rate (OLR) of 1.5 g VS/kg d (VS: volatile solids). Then, a different by-product from the refining of oil was added to the feed of each reactor at an OLR of 0.5 g VS/kg d, generating a 33% increase in the OLR. The results show that the addition of by-products from the refining of oil is an efficient way of increasing the methane production of co-digestion reactors thanks to high methane yield of such by-products (0.69–0.77 l CH4/g VS loaded). In fact, in this work, it was possible to raise the methane production of the reactors by about 60% through a 33% increase in the OLR thanks to the addition of the by-products from the refining of vegetable oil.

scholarly journals Effect of increasing the organic loading rate on the co-digestion and mono-digestion of cattle slurry and maize

2012 ◽  
Vol 66 (11) ◽  
pp. 2336-2342 ◽  
Author(s):  
M. Cornell ◽  
C. J. Banks ◽  
S. Heaven
Keyword(s):  
Loading Rate ◽  
Laboratory Scale ◽  
Methane Yield ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Cattle Slurry ◽  
Biogas Yield ◽  
Loading Rates ◽  
Volatile Solids ◽  
Rate Of Loading

Co-digestion of cattle slurry and maize has been shown to have benefits for both, improving the biogas yield of the slurry and stability of digestion of the maize. The effect of increasing the total loading rate from 3 to 6 g VS l–1 day–1 on the co-digestion of cattle slurry and maize, mixed at equal volatile solids volumes, was investigated in laboratory-scale continuously stirred digesters. These were compared with similar digesters evaluating the increase of 1.5 to 3 g VS l−1 day−1 loading rates of slurry and maize digested separately. Compared with mono-digestion of the substrates, where the digestion of maize failed at loading rates greater than 2.5 g VS l−1 day−1, the co-digestion of cattle slurry and maize was feasible at all the loading rates tested with an increase in the volumetric methane yield occurring with loading rate. Even at the lowest rate of loading, the addition of equal amounts of volatile solids of maize to slurry leads to an increase in volumetric methane yield of 219%.

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.

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