Experiences with anaerobic treatment of fat-containing food waste liquids: two full scale studies with a novel anaerobic flotation reactor

2013 ◽  
Vol 69 (7) ◽  
pp. 1386-1394 ◽  
Author(s):  
C. T. M. J. Frijters ◽  
T. Jorna ◽  
G. Hesselink ◽  
J. Kruit ◽  
D. van Schaick ◽  
...  
Keyword(s):  
Food Waste ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Cod Removal ◽  
Loading Rates ◽  
Study Results ◽  
New Type ◽  
High Concentrations ◽  
Volumetric Loading

Fat-containing food waste can be effectively treated in a new type of reactor, the so-called BIOPAQ-Anaerobic Flotation Reactor or BIOPAQ® anaerobic flotation reactor (AFR). In the reactor a flotation unit is integrated to retain the sludge. In this study results from two plants with a 430 and 511 m3-AFR, respectively, are presented. In one reactor, which is fed with water originating from different food liquid streams, over 99% of fat and oils were removed. Over 90% of the chemical oxygen demand (COD) was removed. When the last solids were removed from the effluent with a tilted plate settler, 98% COD removal was attained. The effluent concentrations of extractable hydrolysed and non-hydrolysed fats were less than 40 mg/l. Apparently the variations in the liquid streams deriving from the tank cleaning activities did not disturb the system. Only extremely high concentrations of fats could disturb the system, but the inhibition was reversible. In the reactor treating water from an ice-cream factory, which contained fats up to approximately 50% of influent COD, a COD removal efficiency of 90% was achieved. At volumetric loading rates varying from 1 to 8 kg COD/m3/d, biogas was produced at an average specific gas production of 0.69 m3/kg COD–removed.

Anaerobic Treatment of Cheese Dairy Wastewater Using the SNC Bioreactor

1993 ◽  
Vol 28 (3) ◽  
pp. 597-620 ◽  
Author(s):  
Catherine N. Mulligan ◽  
Bechara F. Safi ◽  
Jacques Meunier ◽  
Jean Chebib
Keyword(s):  
Retention Time ◽  
Removal Rate ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Cod Removal ◽  
Dairy Wastewater ◽  
Organic Load ◽  
Whey Permeate ◽  
Cod Removal Rate

Abstract The SNC multiplate reactor (1,200 L) has been developed and tested to determine chemical oxygen demand (COD) removal, nutrient requirement, and gas production from the anaerobic treatment of effluents generated at the Agropur (Notre Dame-du-Bon-Conseil, Quebec) and Nutrinor cheese dairies (Chambord, Quebec). At the Agropur plant, wastewater (3,000 mg/L COD) was treated the best at a retention time of 12 h. Using this retention time, effluents containing whey with organic loads of 10.2 to 41.6 kg COD/m3/day could be treated at a 84% COD removal rate. When the reactor was subjected to shock by increasing the organic load suddenly from 8.9 to 31 kg COD/m3/day, the total COD removal decreased to 72% and then returned to 86% after 7 days. Hydrology tests indicated that the reactor functions as a series of completely mixed stirred tanks. At Nutrinor, using a 12-h retention time and diluted whey permeate (20,000 mg/L COD), total COD removal was 86% and gas production was 12.0 m3/m3/day for a loading of 36.5 kg COD/m3/day. Nutrient supplementation was not required. For experiments performed with different proportions of wastewater (2,000 mg/L COD) to whey permeate (70,000 mg/L COD) results of 89% total and 93% soluble COD removal with a gas production of 11 m3/m3/day for a loading of 25 kg COD/m3/day were obtained. Retention times were varied from 18 to 60 h to correspond to initial CODs of 20,000 to 70,000 mg/L. In conclusion, this reactor functions in a superior manner to other published anaerobic treatment systems.

scholarly journals Comparison of thermophilic and mesophilic anaerobic treatment for potato processing wastewater using a contact reactor

2017 ◽  
Vol 19 (2) ◽  
pp. 318-326 ◽  
Keyword(s):  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Organic Loading ◽  
Potato Processing ◽  
Loading Rates ◽  
Methane Gas ◽  
Acid Ratio ◽  
Mesophilic Conditions ◽  
Better Than

In this study, different organic loading rates (OLRs) ranging from 1.1 to 5.0 kg COD/m3·day were used to assess the performance of an anaerobic reactor at the optimum mesophilic (35°C) and thermophilic (55°C) temperatures. The methane gas production rate of the thermophilic treatment was higher than that of the mesophilic treatment. The efficiency of chemical oxygen demand (COD) removal was observed to range from 89.12 to 93.20% following the thermophilic anaerobic treatment and from 76.36 to 92.62% following the mesophilic treatment. The average VFA (volatile fatty acid)/alkalinity ratio of the effluent was 0.3 under both thermophilic and mesophilic conditions for all the OLR applications. The HPr/HAc (propionic acid/acetic acid) ratio was calculated as 0.16 and 1.3 for the mesophilic and thermophilic treatments, respectively. For the mesophilic treatment, the average methane gas production was found to be 0.394 m3 CH4/kg CODremoved while it was 0.42 m3 CH4/kg CODremoved for the thermophilic experiment. However, the sludge settleability of the mesophilic treatment was better than that of the thermophilic treatment.

Microbial sulphate reduction during anaerobic digestion: EGSB process performance and potential for nitrite suppression of SRB activity

2005 ◽  
Vol 52 (1-2) ◽  
pp. 371-376 ◽  
Author(s):  
C. O'Reilly ◽  
E. Colleran
Keyword(s):  
Anaerobic Digestion ◽  
Removal Efficiency ◽  
Fold Increase ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Sulphate Reduction ◽  
Process Performance ◽  
Loading Rates ◽  
Removal Efficiencies ◽  
Volumetric Loading

The present study investigated mesophilic anaerobic treatment of sulphate-containing wastewater in EGSB reactors and assessed the inclusion of nitrite in the reactor influent as a method for control of biological sulphate reduction. Two EGSB reactors, R1 and R2, were operated for a period of 581 days at varying volumetric loading rates, COD/SO42− ratios and influent nitrite concentrations (R2 only). COD removal efficiencies of >93% were achieved in both reactors at influent sulphate concentrations of up to 3,000 mg l−1. A two-fold increase in the influent sulphate concentration, giving an influent COD/SO42− ratio of 2, resulted in a reduction in reactor COD removal efficiency to 84% and 89%, in R1 and R2, respectively. Despite inclusion of nitrite in the R2 influent at concentrations up to 500 mg NO2-N l−1, sulphate reduction proceeded similarly in R2 and R1, suggesting the ineffectiveness of nitrite as a potential inhibitor of SRB activity.

Anaerobic treatment of food waste in pilot scale

2016 ◽  
Vol 11 (4) ◽  
pp. 774-783 ◽  
Author(s):  
Alexsandro dos Santos Reis ◽  
Savia Gavazza ◽  
Simone Machado Santos
Keyword(s):  
Food Waste ◽  
Oxygen Demand ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Ammonia Nitrogen ◽  
Gas Production ◽  
Pollutant Removal ◽  
Organic Loading Rate ◽  
Solids Removal ◽  
Effluent Characteristics

For this work, a pilot scale anaerobic digester was used to assess the treatability of food waste from a canteen. The digester was operated for 720 days, and its efficiency in removing organic matter and suspended solids as well as producing biogas were assessed. At the beginning of operation, the digester failed and alkalinity buffering was required until stabilization. A maximum chemical oxygen demand (COD) and total solids removal efficiency of 71% and 87% were, respectively, found for the organic loading rate of 0.59 kg COD m−3 d−1. The maximum gas production rate and specific gas production were 0.4 m3 m−3 d−1 and 0.76 m3 (kg TVS)−1, respectively, with a methane average of 60% in the biogas composition. Although achieving satisfactory levels of pollutant removal, the effluent characteristics particularly for COD and ammonia nitrogen indicated that recirculation is the best option to use effluent.

scholarly journals Optimization of the COD Removal Efficiency for a Static Granular Bed Reactor Treating Poultry Slaughterhouse Wastewater

2019 ◽  
Author(s):  
Zainab Rinquest ◽  
Moses Basitere ◽  
Maxwell Mewa-Ngongang ◽  
Seteno Karabo Obed Ntwampe ◽  
Mahomet Njoya
Keyword(s):  
South African ◽  
Removal Efficiency ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Granular Bed ◽  
Organic Loading ◽  
Loading Rates ◽  
Cod Removal Efficiency ◽  
Static Granular Bed Reactor

In this study, the efficiency of an anaerobic treatment system for wastewater from a South African poultry slaughterhouse was evaluated using a lab-scale static granular bed reactor (SGBR). The down-flow SGBR (2 L) was operated continuously for 138 days under mesophilic conditions (35-37 ˚C), at hydraulic retention times (HRTs) ranging from 24 to 96 h and average organic loading rates (OLRs) of 0.78 to 5.74 g COD/L.day. The SGBR achieved an average chemical oxygen demand (COD) removal efficiency of 80% and the maximum COD removal achieved was 95%, at an HRT of 24 h and average OLR of 5.74 g COD/L.day. The optimization of the SGBR, with regard to a suitable HRT and OLR, was determined using response surface methodology (RSM). The optimal SGBR performance with regard to the maximum COD removal efficiency was predicted for an OLR of 12.49 g COD/L.day and a HRT of 24 h, resulting in a 95.5% COD removal efficiency. The model R2 of 0.9638 indicated that the model is a good fit and is suitable to predict the COD removal efficiency for the SGBR.

COD removal efficiency and mechanism of HMBR in high volumetric loading for ship domestic sewage treatment

2016 ◽  
Vol 74 (7) ◽  
pp. 1509-1517 ◽  
Author(s):  
Linan Zhu ◽  
Hailing He ◽  
Chunli Wang
Keyword(s):  
Removal Efficiency ◽  
Removal Rate ◽  
Sewage Treatment ◽  
Oxygen Demand ◽  
Domestic Sewage ◽  
Cod Removal ◽  
Aeration Tank ◽  
Remarkable Effect ◽  
Cod Removal Efficiency ◽  
Volumetric Loading

The hybrid membrane bioreactor (HMBR) has been applied in ship domestic sewage treatment under high volumetric loading for ship space saving. The mechanism and influence factors on the efficiency, including hydraulic retention time (HRT), dissolved oxygen (DO) of chemical oxygen demand (COD) removal were investigated. The HMBR's average COD removal rate was up to 95.13% on volumetric loading of 2.4 kgCOD/(m3•d) and the COD concentration in the effluent was 48.5 mg/L, far below the International Maritime Organization (IMO) discharge standard of 125 mg/L. DO had a more remarkable effect on the COD removal efficiency than HRT. In addition, HMBR revealed an excellent capability of resisting organics loading impact. Within the range of volumetric loading of 0.72 to 4.8 kg COD/(m3•d), the effluent COD concentration satisfied the discharge requirement of IMO. It was found that the organics degradation in the aeration tank followed the first-order reaction, with obtained kinetic parameters of vmax (2.79 d−1) and Ks (395 mg/L). The original finding of this study had shown the effectiveness of HMBR in organic contaminant degradation at high substrate concentration, which can be used as guidance in the full scale of the design, operation and maintenance of ship domestic sewage treatment devices.

Anaerobic treatment of proteinaceous wastewater under mesophilic and thermophilic conditions

1999 ◽  
Vol 40 (1) ◽  
pp. 77-84 ◽  
Author(s):  
H. H. P. Fang ◽  
D. Wai-Chung Chung
Keyword(s):  
Bacterial Species ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Upflow Anaerobic Sludge Blanket ◽  
Anaerobic Sludge ◽  
Loading Rates ◽  
Batch Tests ◽  
Thermophilic Conditions ◽  
Anaerobic Sludge Blanket ◽  
Hydrolysis Of

Experiments were conducted in two 2.8 liter UASB (upflow anaerobic sludge blanket) reactors treating proteinaceous wastewaters at 37° and 55°C with 9 hours of hydraulic retention. Results showed that the mesophilic reactor consistently removed 83.5-85.1% of COD (chemical oxygen demand) at loading rates ranging 8-22 g COD l−1 d−1 (corresponding to 3000-8250 mg l−1 of proteinaceous COD in wastewater), whereas the thermophilic reactor removed only 68.5-82.7%. At 32 g COD l−1 d−1 (i.e. 12000 mg COD l−1), the removal efficiencies were lowered to 75.7% in the mesophilic reactor and 65.1% in the thermophilic reactor. At 42 g COD l−1 d−1, severe sludge washout occurred in the mesophilic reactor; at the same loading rate, the thermophilic reactor removed only 53.8% of COD even though sludge washout was under control. The degradation rate in the both reactors was limited by the initial hydrolysis of proteins. However, batch tests showed that thermophilic sludge had slightly higher methanogenic activities than mesophilic sludge in treating proteins and intermediate acids, except propionate. The sludge yields in mesophilic and thermophilic reactors were 0.066 and 0.099 g VSS g COD−1, respectively. Observations by scanning electron microscopy indicated that both types of sludge granules were of irregular shape. There was little noticeable difference between the two granules; both had neither a layered microstructure nor a predominant bacterial species.

Improvement of anaerobic treatment of tannery beamhouse wastewater by an integrated sulphide elimination process

1999 ◽  
Vol 40 (1) ◽  
pp. 245-252 ◽  
Author(s):  
H. Schenk ◽  
M. Wiemann ◽  
W. Hegemann
Keyword(s):  
Hydrogen Sulphide ◽  
Fixed Bed ◽  
Anaerobic Treatment ◽  
Methanogenic Bacteria ◽  
Cod Removal ◽  
Batch Tests ◽  
Treatment Processes ◽  
Fixed Bed Reactors ◽  
Sulphide Toxicity ◽  
High Concentrations

Sulphide, and especially the undissociated form, hydrogen sulphide, is inhibitory to anaerobic wastewater treatment processes. Tannery beamhouse wastewater contains high concentrations of organic material which make an anaerobic treatment favourable, but it also contains high concentrations of sulphide which cause difficulties for anaerobic treatment. The success of an anaerobic treatment will depend on reliable elimination of the sulphide. In batch tests stripping was the most effective process for sulphide removal compared to precipitation. The chemical-physical COD removal caused by the stripping was negligible, while precipitation caused a COD-removal of 26%. Also, anaerobic degradation velocity was higher if sulphide was removed by stripping. In fixed bed reactors operated continuously, stripping was shown to be a reliable method for eliminating hydrogen sulphide toxicity. Hydrogen sulphide caused an inhibition of 0.2% per mg 1−1 for methanogenic bacteria. Acidogenic bacteria were not inhibited by hydrogen sulphide. The gas-liquid equilibrium was shown to deviate from theoretical values taken from literature.

Anaerobic treatment of sulfate-containing municipal wastewater with a fluidized bed reactor at 20 °C

2016 ◽  
Vol 73 (10) ◽  
pp. 2446-2452 ◽  
Author(s):  
B. Düppenbecker ◽  
P. Cornel
Keyword(s):  
Fluidized Bed ◽  
Removal Efficiency ◽  
Municipal Wastewater ◽  
Oxygen Demand ◽  
Fluidized Bed Reactor ◽  
Anaerobic Treatment ◽  
Cod Removal ◽  
Sulfate Reducing ◽  
Mass Flows ◽  
Reducing Bacteria

This study focuses on the anaerobic treatment of sulfate-containing municipal wastewater at 20 °C with a fluidized bed reactor. Mean influent chemical oxygen demand (COD) and sulfate concentrations were 481 and 96 mg/l. The response of the COD removal efficiency to increasing organic loading rates (OLR) was investigated. Average total COD removal was 61% at OLR between 2.7 and 13.7 kg COD/(m³·d) and did not distinctly depend on the OLR. To assess the removal efficiency in more detail the COD in- and output mass flows were balanced. The results showed that only 11–12% of the input COD was recovered as gaseous methane. About 12–13% of the input COD remained in the effluent as dissolved methane. Furthermore, a distinct amount of 12–19% of the input COD remained in the reactor as settled sludge and was not further biologically degraded. Due to the reduction by sulfate-reducing bacteria, 13–14% of the input COD was degraded. Further adverse impacts of the influent sulfate on the anaerobic treatment process are discussed as well.

ANAEROBIC TREATMENT OF DISTILLERY SLOPS IN THE CIRCUMSTANCES OF CENTRAL EUROPE

1994 ◽  
Vol 30 (3) ◽  
pp. 157-160
Author(s):  
Pavel Jenícek ◽  
Jana Zábranská ◽  
Michal Dohányos
Keyword(s):  
Central Europe ◽  
Raw Materials ◽  
Pilot Scale ◽  
Anaerobic Treatment ◽  
Gas Production ◽  
Raw Material ◽  
Uasb Reactor ◽  
Suitable Material ◽  
Large Production ◽  
Volumetric Loading

Anaerobic treatment of many kinds of slops is one of the most progressive ways for the reuse of this material. The special feature of Central Europe is that the largest proportion of ethanol is produced by fermentation, and the raw material in big distilleries is only sugar beet molasses. The consequence of this is a large production of slops in small regions, and as far as the quality of slops is concerned, a relatively high content of inert and nonbiodegradable organic compounds in comparison with other more valuable raw materials, such as grapes, fruits, cereals, potatoes, etc. A two-year operation of the pilot scale UASB reactor bas shown that molasses slops are a suitable material for anaerobic treatment The slops were diluted by other wastewaters from the distillery to a concentration of about 25 g.l‒1 COD and then treated in the pilot reactor at 32°C with the following average results: COD removal efficiency 78.8 %; volumetric loading rate 7.1 kg.m-3.d‒1; volumetric gas production 2.6 m3.m‒3.d‒1; specific gas production 0.47 m3.kg‒1. The results achieved confi11II that molasses slops are a source of energy. For example, Czech distilleries could potentially produce 12-17 million m3 of the valuable gas fuel per annum.

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