Cultivation of microalgae on liquid anaerobic digestate for depollution, biofuels and cosmetics: a review

Tawfik, Ahmed; Eraky, Mohamed; Alhajeri, Nawaf S.; Osman, Ahmed I.; Rooney, David

doi:10.1007/s10311-022-01481-2

Cited by 46 publications

(22 citation statements)

References 219 publications

(205 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Comparing the present study with previous papers reported in Table 1 and with a recent review by Tawfick et al [38], it emerges that the present results are similar to or even better than those reached using pure cultures. Regarding the use of mixed cultures, the present results are similar to those reached by Ermis et al [39], who studied a mixed (open) microalgal consortium using the liquid fraction of the digestate from an AD plant treating the organic fraction of the municipal solid waste, cattle and chicken manure and the expired market waste and leaching water from waste collection vehicles.…”

Section: Discussionsupporting

confidence: 89%

Opportunities and Challenges from Symbiosis of Agro-Industrial Residue Anaerobic Digestion with Microalgae Cultivation

Policastro

Cesaro²,

Fabbricino³

et al. 2022

Sustainability

View full text Add to dashboard Cite

During the last few years, many studies have tested microalgal systems for nitrogen removal from the digestate. However, most of these studies were carried out using pure culture microalgal strains, which require aseptic conditions and thus cannot be used in full-scale applications. The aim of the present study was to explore opportunities in and challenges of the industrial symbiosis of anaerobic digestion and microalgae cultivation to enhance agro-industrial residue management. Batch tests were carried out to investigate the use of a mixed (open) microalgal consortium to treat the liquid fraction of the digestate for nitrogen removal. Preliminary experiments were performed to choose the carbon supply condition optimizing the growth of the open mixed consortium. In detail, the investigated carbon sources were bicarbonate, under two different carbon to nitrogen ratios, CO2 via the free surface and CO2 via air flushing. Further tests were conducted to compare the use of ammoniacal and nitric nitrogen sources. Then, the effectiveness of the liquid fraction of the digestate as nitrogen source was assessed. The highest biomass concentration of 1.6 g L−1 was obtained using CO2 as carbon source via air flushing as feeding strategy and ammoniacal nitrogen. Biomass production was lower (0.6 g L−1) under the digestate. Nonetheless, due to a probable symbiosis between microalgae and bacteria, a total nitrogen removal of 98.5% was achieved, which was the highest obtained in the present study. Such experimental results address the identification of the steps needed for larger-scale application of combined anaerobic digestion and mixed microalgal systems.

show abstract

Section: Discussionsupporting

confidence: 89%

Opportunities and Challenges from Symbiosis of Agro-Industrial Residue Anaerobic Digestion with Microalgae Cultivation

Policastro

Cesaro²,

Fabbricino³

et al. 2022

Sustainability

View full text Add to dashboard Cite

show abstract

“…The method also reduces the cost of nutrient inputs. Additionally, cultivation of E. gracilis using this technique in combination with industrial nutrient wastes, anaerobic digestates of organic wastes, and exhaust CO 2 from power plants could promote a circular economy and contribute to a clean and sustainable environment 9 , 47 . Furthermore, this approach may be applied to other microalgae, providing a sustainable source of biofuels and other bioproducts.…”

Section: Discussionmentioning

confidence: 99%

New insights into raceway cultivation of Euglena gracilis under long-term semi-continuous nitrogen starvation

Bakku¹,

Yamamoto²,

Inaba³

et al. 2023

Sci Rep

View full text Add to dashboard Cite

This study aimed to investigate the physiological responses of Euglena gracilis (E. gracilis) when subjected to semicontinuous N-starvation (N−) for an extended period in open ponds. The results indicated that the growth rates of E. gracilis under the N− condition (11 ± 3.3 g m−2 d−1) were higher by 23% compared to the N-sufficient (N+, 8.9 ± 2.8 g m−2 d−1) condition. Furthermore, the paramylon content of E.gracilis was above 40% (w/w) of dry biomass in N− condition compared to N+ (7%) condition. Interestingly, E. gracilis exhibited similar cell numbers regardless of nitrogen concentrations after a certain time point. Additionally, it demonstrated relatively smaller cell size over time, and unaffected photosynthetic apparatus under N− condition. These findings suggest that there is a tradeoff between cell growth and photosynthesis in E. gracilis, as it adapts to semi-continuous N− conditions without a decrease in its growth rate and paramylon productivity. Notably, to the author’s knowledge, this is the only study reporting high biomass and product accumulation by a wild-type E. gracilis strain under N− conditions. This newly identified long-term adaptation ability of E. gracilis may offer a promising direction for the algal industry to achieve high productivity without relying on genetically modified organisms.

show abstract

“…and Scenedesmus spp. on the agricultural anaerobic digestate has been extensively discussed by Tawfik et al (2022). This approach is a promising solution for nutrient recovery and pollutant removal and achieves maximum valorization of digestate.…”

Section: Integrating Pyrolysis With Algae Cultivation For Emission Re...mentioning

confidence: 99%

Materials, fuels, upgrading, economy, and life cycle assessment of the pyrolysis of algal and lignocellulosic biomass: a review

et al. 2023

Self Cite

View full text Add to dashboard Cite

Climate change issues are calling for advanced methods to produce materials and fuels in a carbon–neutral and circular way. For instance, biomass pyrolysis has been intensely investigated during the last years. Here we review the pyrolysis of algal and lignocellulosic biomass with focus on pyrolysis products and mechanisms, oil upgrading, combining pyrolysis and anaerobic digestion, economy, and life cycle assessment. Products include oil, gas, and biochar. Upgrading techniques comprise hot vapor filtration, solvent addition, emulsification, esterification and transesterification, hydrotreatment, steam reforming, and the use of supercritical fluids. We examined the economic viability in terms of profitability, internal rate of return, return on investment, carbon removal service, product pricing, and net present value. We also reviewed 20 recent studies of life cycle assessment. We found that the pyrolysis method highly influenced product yield, ranging from 9.07 to 40.59% for oil, from 10.1 to 41.25% for biochar, and from 11.93 to 28.16% for syngas. Feedstock type, pyrolytic temperature, heating rate, and reaction retention time were the main factors controlling the distribution of pyrolysis products. Pyrolysis mechanisms include bond breaking, cracking, polymerization and re-polymerization, and fragmentation. Biochar from residual forestry could sequester 2.74 tons of carbon dioxide equivalent per ton biochar when applied to the soil and has thus the potential to remove 0.2–2.75 gigatons of atmospheric carbon dioxide annually. The generation of biochar and bio-oil from the pyrolysis process is estimated to be economically feasible.

show abstract

Cultivation of microalgae on liquid anaerobic digestate for depollution, biofuels and cosmetics: a review

Cited by 46 publications

References 219 publications

Opportunities and Challenges from Symbiosis of Agro-Industrial Residue Anaerobic Digestion with Microalgae Cultivation

Opportunities and Challenges from Symbiosis of Agro-Industrial Residue Anaerobic Digestion with Microalgae Cultivation

New insights into raceway cultivation of Euglena gracilis under long-term semi-continuous nitrogen starvation

Materials, fuels, upgrading, economy, and life cycle assessment of the pyrolysis of algal and lignocellulosic biomass: a review

Contact Info

Product

Resources

About