Towards effective management of digester dysfunction during anaerobic treatment processes

Onwosi, Chukwudi O.; Eke, Ifeanyichukwu E.; Igbokwe, Victor C.; Odimba, Joyce N.; Ndukwe, Johnson K.; Chukwu, Kenechi O.; Aliyu, Godwin O.; Nwagu, Tochukwu Nwamaka

doi:10.1016/j.rser.2019.109424

Cited by 23 publications

(19 citation statements)

References 149 publications

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“…The microorganism groups during AD are sensitive to several factors such as changes in some monitoring parameters including pH, alkalinity, VFAs as well as some operating parameters (temperature, hydraulic retention time, substrate composition, and organic loading rate (OLR)) [6]. As in Fig.…”

Section: Process Key Factorsmentioning

confidence: 99%

“…OLR is among the key operational parameters in AD systems. The biogas production rate is correlated to OLR in a way that maintenance of OLR at an appropriate range promotes biogas yield [6]. However, a significant increase in OLR beyond the suitable range is a major factor of VFAs accumulation, therefore decreasing biogas production [6].…”

Section: Process Key Factorsmentioning

confidence: 99%

“…During AD process, pH is generally within the range (0.6-0.8), its variation depends on the evolution of the fermentation of organic matter. pH is important for the fulfillment of the methanogenic phase since a decrease in pH results in an inhibition of the process [6].…”

Section: Process Key Factorsmentioning

confidence: 99%

“…The concentration of VFAs has been widely suggested for the control and monitoring of anaerobic digesters as it is the main methanogenic intermediate also its accumulation in reactors is reliable in indicating process imbalance [8]. It is mostly used to determine the stress level of the [16] system because it can provide specific information for process diagnosis [6,8]. The measurement of biogas flow and composition is very important because they indicate the overall performance of the digester [8].…”

Section: Process Key Factorsmentioning

confidence: 99%

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Modeling and Optimization of Anaerobic Digestion: A Review

et al. 2021

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Anaerobic digestion is recognized as being an advantageous waste management technique representing a source of clean and renewable energy. However, biogas production through such practice is complex and it relies on the interaction of several factors including changes in operating and monitoring parameters. Enormous researchers have focused and gave their full attention to mathematical modeling of anaerobic digestion to get good insights about process dynamics, aiming to optimize its efficiency. This paper gives an overview of the different approaches applied to tackle this challenge including mechanistic and data-driven models. This review has led us to conclude that neural networks combined with metaheuristic techniques has the potential to outperform mechanistic and classical machine learning models.

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Section: Process Key Factorsmentioning

confidence: 99%

Section: Process Key Factorsmentioning

confidence: 99%

Section: Process Key Factorsmentioning

confidence: 99%

Section: Process Key Factorsmentioning

confidence: 99%

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Modeling and Optimization of Anaerobic Digestion: A Review

et al. 2021

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“…FW is always characterized with low C/N ratio [9]. Thus, the AD process with FW often results in the accumulation of volatile fatty acids (VFAs) in the reaction system, due to the imbalanced nutrition in the substrates [10,11]. Further, the acidification reduces methane yield and destroys the stability of the digestive system, leading to imbalance.…”

Section: Introductionmentioning

confidence: 99%

Effect of yeast addition on the biogas production performance of a food waste anaerobic digestion system

Gao

Zhang

et al. 2020

R. Soc. open sci.

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Food waste contains numerous easily degradable components, and anaerobic digestion is prone to acidification and instability. This work aimed to investigate the effect of adding yeast on biogas production performance, when substrate is added after biogas production is reduced. The results showed that the daily biogas production increased 520 and 550 ml by adding 2.0% (volatile solids; VS) of activated yeast on the 12th and 37th day of anaerobic digestion, respectively, and the gas production was relatively stable. In the control group without yeast, the increase of gas production was significantly reduced. After the second addition of substrate and yeast, biogas production only increased 60 ml compared with that before the addition. After fermentation, the biogas production of yeast group also increased by 33.2% compared with the control group. Results of the analysis of indicators, such as volatile organic acids, alkalinity and propionic acid, showed that the stability of the anaerobic digestion system of the yeast group was higher. Thus, the yeast group is highly likely to recover normal gas production when the biogas production is reduced, and substrate is added. The results provide a reference for experiments on the industrialization of continuous anaerobic digestion to take tolerable measures when the organic load of the feed fluctuates dramatically.

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