Performance of an anaerobic plug-flow reactor treating agro-industrial wastes supplemented with lipids at high organic loading rate

2021 ◽  
pp. 0734242X2199189
Author(s):  
Alexandros Eftaxias ◽  
Dimitrios Georgiou ◽  
Vasileios Diamantis ◽  
Alexandros Aivasidis
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Flow Reactor ◽  
Plug Flow ◽  
Plug Flow Reactor ◽  
Industrial Wastes ◽  
High Rate ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Used Cooking Oil

This study evaluated the performance of a plug-flow reactor (PFR) for high-rate anaerobic co-digestion of complex agro-industrial wastes and used cooking oil or animal fat. The PFR was successfully operated up to an organic loading rate (OLR) of 21 g L−1 d−1, yielding biogas at 0.35 L g−1 chemical oxygen demand (COD) influent. During the study period, supernatant COD at the PFR effluent remained between 4 and 7 g L−1, with negligible volatile fatty acids’ concentrations (<500 mg L−1) and no presence of foaming incidents. The biomass concentration inside the PFR, expressed as total suspended solids, remained between 30 and 60 g L−1. Moreover, the above-mentioned anaerobic digestion technology has been currently scaled-up at 50 m3 PFR, while a full-scale facility of 240 kW-el is under construction in the region of north-eastern Greece.

Phase separation during anaerobic fermentation of solid substrates in an innovative plug-flow reactor

1997 ◽  
Vol 36 (6-7) ◽  
pp. 303-310 ◽  
Author(s):  
Tuanchi Liu ◽  
Sambhunath Ghosh
Keyword(s):  
Phase Separation ◽  
Flow Reactor ◽  
Anaerobic Fermentation ◽  
Plug Flow ◽  
Plug Flow Reactor ◽  
Organic Loading ◽  
Loading Rates ◽  
Solid Substrates ◽  
Solids Content ◽  
Acidogenic Phase

Separation of the liquefaction-acidification and gasification phases of anaerobic digestion was studied in a simple, plug-flow reactor (PFR) charged with 3 to 10 wt% solids-content feed slurries. The unmixed PFR had zigzagging parallel channels with floors sloping towards the outlet. Steady-state runs were conducted at hydraulic retention times of 32 to 13 days and organic loading rates (OLRs) of 0.84 to 6.84 kg-VS/m3-d. Phase separation was first observed when the OLR was 2.05 kg-VS/m3-d. Longitudinal pH and volatile fatty acid (VFA) profiles at this OLR showed a lowest pH of 6.10 and a highest VFA accumulation of 1500 mg/l. The acidogenic phase predominated within the first 50 cm from the inlet, and the methanogenic phase prevailed in the remainder of the PFR. At an OLR of 6.84 kg-VS/m3-d the pH dropped to 4.4, and the VFA accumulated to 9600 mg/l with the acidogenic phase extending to 83 cm from the PFR inlet. Unlike a CSTR digester, the PFR always recovered from the initial sour digestion and afforded high VS reductions of 78 to 63% corresponding to methane yields of 0.36 to 0.28 m3/kg-VS added.

Anaerobic monodigestion of poultry manure: determination of operational parameters for CSTR

2012 ◽  
Vol 65 (1) ◽  
pp. 53-59 ◽  
Author(s):  
R. Chamy ◽  
C. León ◽  
E. Vivanco ◽  
P. Poirrier ◽  
C. Ramos
Keyword(s):  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Poultry Manure ◽  
Organic Loading Rate ◽  
Continuous Stirred Tank Reactor ◽  
Organic Loading ◽  
Operational Parameters ◽  
Volatile Solids ◽  
High Alkalinity ◽  
Vs Removal

In this work the anaerobic monodigestion for the treatment of turkey manure was evaluated, without its codigestion with another substrate. The effect of the organic loading rate (OLR) and the substrate concentration (high total solids (TS) concentration) or product concentration (high volatile fatty acids (VFA) and/or ammonia (NH3-N) concentrations) was studied. The results show that for a continuous stirred tank reactor (CSTR) operation, a maximum of 40 g/L of TS and 4.0 g/L of ammonium (NH4+) was required. In addition, the maximum organic loading rate (OLR) will not exceed 1.5 kg VS/m3d. Higher TS and NH4+ concentrations and OLR lead to a reduction on the methane productivity and volatile solids (VS) removal. During the CSTR operation, a high alkalinity concentration (above 10 g/L CaCO3) was found; this situation allowed maintaining a constant and appropriate pH (close to 7.8), despite the VFA accumulation. In this sense, the alkalinity ratio (α) is a more appropriate control and monitoring parameter of the reactor operation compared to pH. Additionally, with this parameter a VS removal of 80% with a methane productivity of 0.50 m3CH4/m3Rd is achieved.

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.

Volatile fatty acids production from food waste: Effects of pH, temperature, and organic loading rate

2013 ◽  
Vol 143 ◽  
pp. 525-530 ◽  
Author(s):  
Jianguo Jiang ◽  
Yujing Zhang ◽  
Kaimin Li ◽  
Quan Wang ◽  
Changxiu Gong ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Food Waste ◽  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Effects Of Ph

scholarly journals Effect of Organic Loading Rate on Anaerobic Digestion Performance of Mesophilic (UASB) Reactor Using Cattle Slaughterhouse Wastewater as Substrate

2018 ◽  
Vol 15 (10) ◽  
pp. 2220 ◽  
Author(s):  
Mohammed Musa ◽  
Syazwani Idrus ◽  
Che Hasfalina ◽  
Nik Daud
Keyword(s):  
Methane Concentration ◽  
Volatile Fatty Acids ◽  
Loading Rate ◽  
Cod Removal ◽  
Upflow Anaerobic Sludge Blanket ◽  
Uasb Reactor ◽  
Organic Loading Rate ◽  
Anaerobic Sludge ◽  
Organic Loading ◽  
Slaughterhouse Wastewater

In this study, the performance of a laboratory scale upflow anaerobic sludge blanket (UASB) reactor operating at mesophilic temperature (35 °C) was examined. Cattle slaughterhouse wastewater (CSWW) was used as the main substrate. The total and effective volumes of the reactor were 8 L and 6 L, respectively. Twelve different organic loading rates (OLR) were applied and the performance was evaluated. The chemical oxygen demand (COD) removal efficiency was more than 90% during batch study. In the continuous study, COD removal was also approximately 90% at OLR 0.4 g/L d−1 which subsequently dropped to below 50% when the loading rate increased to 15 g/L d−1. Approximately 5 L/d of biogas was obtained with high methane concentration at stages VI and XI corresponding to OLR of 2 and 10 g/L d−1, respectively. It was observed that the concentration of volatile fatty acids was low and that the alkalinity of the wastewater was sufficient to avoid acidification. Specific methane yields of 0.36 and 0.38 LCH4/g COD added were achieved at OLR 7 and 10 g/L d−1. A hydraulic retention time (HRT) of 1 day was sufficient to remove greater than 70% of COD which correspond to 89% methane concentration. Parameters like soluble COD, NH3-N, pH, alkalinity, total suspended solid (TSS), fats, oil, and grease were also investigated. The results show that the UASB reactor could serve as a good alternative for anaerobic treatment of CSWW and methane production.

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