Kinetic investigations into the effect of inoculum to substrate ratio on batch anaerobic digestion of simulated food waste

Gandhi, Bhushan P.; Otite, Saanu Victoria; Fofie, Esther A.; Lag-Brotons, Alfonso J.; Ezemonye, Lawrence Ikechukwu; Semple, Kirk T.; Martin, Alastair

doi:10.1016/j.renene.2022.05.134

Cited by 17 publications

(15 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Gandhi et al. [ 39 ] also found evidence that high bacterial concentrations can harm biogas production, observing that adding a larger amount of inoculum can lead to the accumulation of volatile fatty acids and pH reduction, compromising microorganism activity and reducing biogas production in laboratory‐scale experiments. In the experimental design assays, the lower volume results presented both EB ( x 2 ) and CA ( x 3 ) variables in high concentration.…”

Section: Resultsmentioning

confidence: 99%

“…Although high bacterial concentrations can accelerate the rate of organic matter degradation, it can also generate excess organic acids, inhibiting microorganisms responsible for biogas production and compromising the efficiency of the process. Gandhi et al [39] also found evidence that high bacterial concentrations can harm biogas production, observing that adding a larger amount of inoculum can lead to the accumulation of volatile fatty acids and pH reduction, compromising microorganism activity and reducing biogas production in laboratory-scale experiments. In the experimental design assays, the lower volume results presented both EB (x 2 ) and CA (x 3 ) variables in high concentration.…”

Section: Experimental Designmentioning

confidence: 99%

See 1 more Smart Citation

Advancements in biodigester technology through the study of anaerobic digestion using statistical optimization and bioaccelerators

Monteiro,

Mariano,

Padilha

et al. 2023

CLEAN Soil Air Water

View full text Add to dashboard Cite

Advances in biodigester technology have been promoted by the growing study of anaerobic digestion, with the aim of improving processes related to the utilized waste load. This research used the statistical tool Central Composite Rotatable Design to optimize the combination of microorganisms and enzymes for biodigestion. The experiment involved testing two microorganisms (EA and EB) and five enzymes (amylase, protease, lipase, cellulase, and amyloglucosidase) with food waste from nearby restaurants and WWTP sludge as an inoculant. The experiment was set up as Central Composite Rotatable Design (CCRD) 26‐1, with 50 trials and a concentration of 14.5 g of volatile solids per liter. The dependent variables of cumulative biogas production (BG) and cumulative biomethane production (BM) were evaluated. The results showed that the independent variables EB and CA had negative and significant effects on BG and BM production. With optimized process conditions, the bioaccelerator significantly improved BG and BM responses compared to control trials by 72% and 88%, respectively. The biodigestion technique is a viable option for the treatment of organic waste, and the use of bioaccelerators may be a promising approach to improving biodigestion processes. This study contributes to the ongoing research on anaerobic digestion and biodigester technology, which seeks to improve the sustainable management of organic waste while producing renewable energy.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Experimental Designmentioning

confidence: 99%

Advancements in biodigester technology through the study of anaerobic digestion using statistical optimization and bioaccelerators

Monteiro,

Mariano,

Padilha

et al. 2023

CLEAN Soil Air Water

View full text Add to dashboard Cite

show abstract

“…The experiment was set up as described by Gandhi et al [ 25 ]. Briefly, the batch bioreactors consisted of five treatments each in duplicate, and controls also in duplicate, totaling twelve reactors.…”

Section: Methodsmentioning

confidence: 99%

“…The effects of ISR on the AD process stability and biogas production have been studied [ 1 , 20 , 22 , 23 , 24 , 25 ], but there is little work that has been performed on the effect of ISR on pathogen kinetics. Although Arias et al [ 26 ] reported the effect of high total solids on pathogen inactivation during batch mesophilic AD of agricultural residue, and Fagbohungbe et al [ 27 ] investigated the effect of ISR on batch AD of human faecal material, both authors used different feedstock and pathogen detection methods and reported results for only the initial and final pathogen loadings.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of the Inoculum-to-Substrate Ratio on Putative Pathogens and Microbial Kinetics during the Batch Anaerobic Digestion of Simulated Food Waste

Otite,

Gandhi,

Agyabeng Fofie

et al. 2024

Microorganisms

Self Cite

View full text Add to dashboard Cite

The effects of the inoculum (anaerobic digestion effluent) to substrate (simulated food waste) ratio (ISR) 4.00 to 0.25 on putative pathogens and microbial kinetics during batch mesophilic anaerobic digestion were investigated. Red fluorescent protein labelled (RFPAKN132) Escherichia coli JM105 was introduced as a marker species, and together with the indigenous Clostridium sp., Enterococcus sp., Escherichia coli, and total coliforms were used to monitor pathogen death kinetics. Quantitative polymerase chain reaction was also used to estimate the bacterial, fungal, and methanogenic gene copies. All the ISRs eliminated E. coli and other coliforms (4 log10 CFU/mL), but ISR 0.25 achieved this within the shortest time (≤2 days), while ISR 1.00 initially supported pathogen proliferation. Up to 1.5 log10 CFU/mL of Clostridium was reduced by acidogenic conditions (ISR 0.25 and 0.50), while Enterococcus species were resistant to the digestion conditions. Fungal DNA was reduced (≥5 log10 copies/mL) and was undetectable in ISRs 4.00, 2.00, and 0.50 at the end of the incubation period. This study has demonstrated that ISR influenced the pH of the digesters during batch mesophilic anaerobic digestion, and that acidic and alkaline conditions achieved by the lower (0.50 and 0.25) and higher (4.00 and 2.00) ISRs, respectively, were critical to the sanitisation of waste.

show abstract

Influence of Inoculum to Substrate Ratio and Substrates Mixing Ratio on Biogas Production from the Anaerobic Co-digestion of Phragmites australis and Food Waste

Al-Iraqi,

Gandhi,

Folkard

et al. 2023

Bioenerg. Res.

View full text Add to dashboard Cite

This study focused on determining the effect of the inoculum to substrate ratio (ISR) on biogas production efficiency from the anaerobic co-digestion of two substrates: synthetic food waste and common reeds (Phragmites australis) that were ground and pre-treated using sodium hydroxide at a concentration of 2% to increase access to their cellulose. It also studied the role of different mixing ratios of the two substrates in improving the stability of the digestion process and increasing biogas production. A series of batch tests were carried out under mesophilic conditions using three ratios of ISR: 1:4, 1:2, and 1:1, and five substrate mixing ratios (synthetic food waste: pre-treated P. australis): 25:75, 50:50, 75:25, 100:0, and 0:100. The results showed low biogas production at the ISR 1:4 (21.58±0.00–44.46±0.01 mL/g volatile solid (VS) added), and the reactors suffered from acidification at the different substrates mixing ratios, while the biogas production increased at an ISR of 1:2, where the reactors with the substrate mixing ratio of 25:75 presented the highest biogas production (82.17±0.62 mL/g VS added), and the digestion process was stable. However, the reactors with substrate mixing ratios of 50:50, 75:25, and 100:0 suffered from acidification effects at this ISR. In contrast, at ISR of 1:1, the reactors did not expose to acidification inhibition at all the substrates mixing ratios, and the highest biogas production was found at synthetic food waste: pre-treated P. australis mixing ratios of 75:25 and 100:0 (76.15±1.85 and 82.47±1.85 mL/g VS added, respectively).

show abstract

Kinetic investigations into the effect of inoculum to substrate ratio on batch anaerobic digestion of simulated food waste

Cited by 17 publications

References 69 publications

Advancements in biodigester technology through the study of anaerobic digestion using statistical optimization and bioaccelerators

Advancements in biodigester technology through the study of anaerobic digestion using statistical optimization and bioaccelerators

Effect of the Inoculum-to-Substrate Ratio on Putative Pathogens and Microbial Kinetics during the Batch Anaerobic Digestion of Simulated Food Waste

Influence of Inoculum to Substrate Ratio and Substrates Mixing Ratio on Biogas Production from the Anaerobic Co-digestion of Phragmites australis and Food Waste

Contact Info

Product

Resources

About