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- Ebrahimian, Farinaz, et al.
(author)
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Iron limitation effect on H2/CO2 biomethanation : Experimental and model analysis
- 2023
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In: Journal of Environmental Chemical Engineering. - : Elsevier. - 2213-3437. ; 11:2
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Journal article (peer-reviewed)abstract
- Trace metals are indispensable for the metalloenzymes involved for efficient H2/CO2 biomethanation. In-depth understanding of trace metals requirements of methanogens cannot only lead to robust and stable operation, but also can enhance CH4 productivity. In this study, the effect of Fe, Mn, Co, Ni, Cu, Zn, Se, Mo and W on the H2/CO2 biomethanation was examined. In a period of nutrient deprivation, suppression of hydrogenotrophic archaea was revealed at higher feed gas rates, leading to a significant drop in CH4 content and a concomitant rise in acetic acid concentration. After nutrient supplementation, the increase in Co, Ni and Fe concentrations were pivotal factors for enhanced methanogenic activity, leading to a CH4 content of more than 98% in the outlet biogas and a sharp drop in acetic acid concentration. Moreover, mathematical modeling was employed to simulate the influence of the most prominent element, iron, on the biomethanation process. The amended BioModel demonstrated that Fe limitation suppresses hydrogenotrophic archaea which consequently leads to H2 accumulation and growth of homoacetogenic bacteria.
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- Khoshnevisan, Benyamin, et al.
(author)
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A critical review on livestock manure biorefinery technologies : Sustainability, challenges, and future perspectives
- 2021
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In: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 135
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Journal article (peer-reviewed)abstract
- An ever increasing demand for animal protein products has posed serious challenges for managing the increasingquantities of livestock manure. The choice of treatment technologies is still a complicated task and considerabledebates over this issue still continue. To build a clearer picture of manure treatment framework, this study wasconducted to review the most frequently employed manure management technologies from their state of the art,challenges, sustainability, environmental regulations and incentives, and improvement strategies perspectives.The results showed that most treatment technologies have focused on the solid fraction of manure while theliquid fraction still remains a potential environmental threat. Compared to other waste to energy solutions,anaerobic digestion is the most mature technology to upgrade manure’s organic matter into renewable energy,however the problems associated with high investment costs, operating parameters, manure collection, anddigestate management have hindered its developments in rural areas in developing countries. Bio-oil productionthrough hydrothermal liquification is also a promising solution, as it can directly convert the wet manure intobiofuel. However, lipid-poor nature of manure, operational difficulties, and the need for downstream process toremove nitrogenous compounds from the final product necessitate further research. Livestock manure management(both solid and liquid fractions) under biorefinery approach seems an inevitable solution for futuresustainable development to meet circular bioeconomy requirements. Much research is still required to establish asystematic framework based on regional requirements to develop an integrated manure nutrient recycling andmanure management planning with minimum environmental risks and maximum profit.
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