Evaluation of single and two stage anaerobic digestion of landfill leachate: Effect of pH and initial organic loading rate on volatile fatty acid (VFA) and biogas production

2018 ◽  
Vol 251 ◽  
pp. 364-373 ◽  
Author(s):  
Sameena Begum ◽  
Gangagni Rao Anupoju ◽  
S. Sridhar ◽  
Suresh K. Bhargava ◽  
Veeriah Jegatheesan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Anaerobic Digestion ◽  
Landfill Leachate ◽  
Volatile Fatty Acid ◽  
Loading Rate ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Two Stage ◽  
Effect Of Ph

scholarly journals Adjusting Organic Load as a Strategy to Direct Single-Stage Food Waste Fermentation from Anaerobic Digestion to Chain Elongation

Processes ◽  
2020 ◽  
Vol 8 (11) ◽  
pp. 1487
Author(s):  
Vicky De Groof ◽  
Marta Coma ◽  
Tom C. Arnot ◽  
David J. Leak ◽  
Ana B. Lanham
Keyword(s):  
Anaerobic Digestion ◽  
Food Waste ◽  
Loading Rate ◽  
Biogas Production ◽  
Single Stage ◽  
Stirred Tank ◽  
Chain Elongation ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Operating Strategy

Production of medium chain carboxylic acids (MCCA) as renewable feedstock bio-chemicals, from food waste (FW), requires complicated reactor configurations and supplementation of chemicals to achieve product selectivity. This study evaluated the manipulation of organic loading rate in an un-supplemented, single stage stirred tank reactor to steer an anaerobic digestion (AD) microbiome towards acidogenic fermentation (AF), and thence to chain elongation. Increasing substrate availability by switching to a FW feedstock with a higher COD stimulated chain elongation. The MCCA species n-caproic (10.1 ± 1.7 g L−1) and n-caprylic (2.9 ± 0.8 g L−1) acid were produced at concentrations comparable to more complex reactor set-ups. As a result, of the adjusted operating strategy, a more specialised microbiome developed containing several MCCA-producing bacteria, lactic acid-producing Olsenella spp. and hydrogenotrophic methanogens. By contrast, in an AD reactor that was operated in parallel to produce biogas, the retention times had to be doubled when fed with the high-COD FW to maintain biogas production. The AD microbiome comprised a diverse mixture of hydrolytic and acidogenic bacteria, and acetoclastic methanogens. The results suggest that manipulation of organic loading rate and food-to-microorganism ratio may be used as an operating strategy to direct an AD microbiome towards AF, and to stimulate chain elongation in FW fermentation, using a simple, un-supplemented stirred tank set-up. This outcome provides the opportunity to repurpose existing AD assets operating on food waste for biogas production, to produce potentially higher value MCCA products, via simple manipulation of the feeding strategy.

Anaerobic digestion of Jatropha curcas L. press cake and effects of an iron-additive

2011 ◽  
Vol 29 (11) ◽  
pp. 1171-1176 ◽  
Author(s):  
Thomas Schmidt
Keyword(s):  
Anaerobic Digestion ◽  
Jatropha Curcas ◽  
Loading Rate ◽  
Press Cake ◽  
Biogas Production ◽  
Organic Loading Rate ◽  
Organic Loading ◽  
Biogas Yield ◽  
Jatropha Curcas L ◽  
The Stability

Oil production from Jatropha curcas L. seeds generates large amounts of Jatropha press cake (JPC) which can be utilized as a substrate for biogas production. The objective of this work was to investigate anaerobic mono-digestion of JPC and the effects of an iron additive (IA) on gas quality and process stability during the increase of the organic loading rate (OLR). With the increase of the OLR from 1.3 to 3.2 gVS L−1 day−1, the biogas yield in the reference reactor (RR) without IA decreased from 512 to 194 LN kgVS−1 and the CH4 concentration decreased from 69.3 to 44.4%. In the iron additive reactor (IAR), the biogas yield decreased from 530 to 462 LN kgVS−1 and the CH4 concentration decreased from 69.4 to 61.1%. The H2S concentration in the biogas was reduced by addition of the IA to values below 258 ppm in the IAR while H2S concentration in the RR increased and exceeded the detection limit of 5000 ppm. The acid capacity (AC) in the RR increased to more than 20 g L−1, indicating an accumulation of organic acids caused by process instability. AC values in the IAR remained stable at values below 5 g L−1. The results demonstrate that JPC can be used as sole substrate for anaerobic digestion up to an OLR of 2.4 gVS l−1 day−1. The addition of IA has effectively decreased the H2S content in the biogas and has improved the stability of the anaerobic process and the biogas quality.

Treatment of municipal landfill leachate: Optimization of organic loading rate in a two-stage CSTR followed by aerobic degradation

2021 ◽  
Vol 163 ◽  
pp. 1210-1221
Author(s):  
Saeed Ghanbari Azad Pashaki ◽  
Mehdi Khojastehpour ◽  
Mohammadali Ebrahimi-Nik ◽  
Abbas Rohani
Keyword(s):  
Landfill Leachate ◽  
Loading Rate ◽  
Organic Loading Rate ◽  
Aerobic Degradation ◽  
Organic Loading ◽  
Two Stage ◽  
Municipal Landfill

scholarly journals Opportunities for Green Energy through Emerging Crops: Biogas Valorization of Cannabis sativa L. Residues

Climate ◽  
2019 ◽  
Vol 7 (12) ◽  
pp. 142 ◽  
Author(s):  
Carla Asquer ◽  
Emanuela Melis ◽  
Efisio Antonio Scano ◽  
Gianluca Carboni
Keyword(s):  
Anaerobic Digestion ◽  
Loading Rate ◽  
Cannabis Sativa ◽  
Biogas Production ◽  
Gas Production ◽  
Enzymatic Treatment ◽  
Laboratory Scale ◽  
Industrial Plant ◽  
Organic Loading Rate ◽  
Organic Loading

The present work shows the experimental evidence carried out on a pilot scale and demonstrating the potential of Cannabis sativa L. by-products for biogas production through anaerobic digestion. While the current state-of-the-art tests on anaerobic digestion feasibility are carried out at the laboratory scale, the here described tests were carried out at a pilot-to-large scale. An experimental campaign was carried out on hemp straw residues to assess the effective performance of this feedstock in biogas production by reproducing the real operating conditions of an industrial plant. An organic loading rate was applied according to two different amounts of hemp straw residues (3% wt/wt and 5% wt/wt). Also, specific bioenhancers were used to maximize biogas production. When an enzymatic treatment was not applied, a higher amount of hemp straw residues determined an increase of the median values of the gas production rate of biogas of 92.1%. This reached 116.6% when bioenhancers were applied. The increase of the specific gas production of biogas due to an increment of the organic loading rate (5% wt/wt) was +77.9% without enzymatic treatment and it was +129.8% when enzymes were used. The best management of the biodigester was found in the combination of higher values of hemp straw residues coupled with the enzymatic treatment, reaching 0.248 Nm3·kgvolatile solids−1 of specific biogas production. Comparisons were made between the biogas performance obtained within the present study and those found in the literature review coming from studies on a laboratory scale, as well as those related to the most common energy crops. The hemp straw performance was similar to those provided by previous studies on a laboratory scale. Values reported in the literature for other lignocellulosic crops are close to those of this work. Based on the findings, biogas production can be improved by using bioenhancers. Results suggest an integration of industrial hemp straw residues as complementary biomass for cleaner production and to contribute to the fight against climate change.

Optimization of Hydraulic Retention Time and Organic Loading Rate in Anaerobic Digestion of Squeezed Pineapple Liquid Wastes for Biogas Production

2021 ◽  
Author(s):  
Napisa Pattharaprachayakul ◽  
Narumon Kesonlam ◽  
Pongpitak Duangjumpa ◽  
Vilai Rungsardthong ◽  
Worakrit Suvajittanont ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Retention Time ◽  
Hydraulic Retention Time ◽  
Loading Rate ◽  
Biogas Production ◽  
Solid Wastes ◽  
Organic Loading Rate ◽  
Hybrid Reactor ◽  
Organic Loading ◽  
Liquid Wastes

Pineapple wastes are produced in huge amount during the industrial canning process of pineapple; in Thailand over 400,000 tons per annum of canned pineapple exported leaving behind the waste. Besides the pulps and peels as solid wastes, the squeezed pineapple liquid wastes (SPLW) extracted from solid wastes can also be used for anaerobic digestion. In the present study, the anaerobic digestion of liquid squeezed from industrial pineapple peels was carried out using a lab-scale hybrid reactor. The reactor was operated for over 170 days with the hydraulic retention time (HRT) of 20 days decreasing down to 5 days and simultaneous control of organic loading rate (OLR). Under controlled conditions in the hybrid reactor, pH was maintained at 6.5–7.6 by adding alkaline for anaerobic microbial activity. Results showed that the chemical oxygen demand (COD) removal efficiency was at ≥ 90% for all conditions. The biogas production (mL/day) increased thoroughly from longer HRT to shorter HRT, as same as methane production with the maximum values (HRT 5 days, OLR 5 g/COD/ day with recirculation) of 55,130 and 30,322 mL/day, respectively. Moreover, the highest yields of biogas and methane were also investigated under similar conditions with the values of 0.504 and 0.277 L/gCOD, respectively. Interestingly, this optimization of both HRT and OLR of lab-scale anaerobic digestion process could be further practically applied to pilot or industrial scale in canned pineapple factories for biogas production.

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