Biogas Production from Algal Biomass from Municipal Wastewater Treatment

Hlavínek, Petr; Stříteský, Luboš; Pešoutová, Radka; Houdková, Lucie

doi:10.1007/s12649-016-9488-2

Cited by 12 publications

(8 citation statements)

References 7 publications

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“…The authors also observed a synergy when mixing both substrates attributed to the C/N ratio increase (Samson and LeDuy, 1983). So far, most research has been conducted co-digesting microalgae with waste activated sludge (WAS) or sewage sludge (Caporgno et al, 2015;Olsson et al, 2014;Thorin et al, 2017), while only a few studies tested microalgae co-digestion with primary sludge in batch test (Hlavínek et al, 2016;Mahdy et al, 2015). A 15% increase in the methane yield was reported after primary sludge co-digestion in biochemical methane potential (BMP) tests (Mahdy et al, 2015).…”

Section: Introductionmentioning

confidence: 99%

Co-digestion of microalgae and primary sludge: Effect on biogas production and microcontaminants removal

Solé-Bundó

Garfí

Matamoros

et al. 2019

Science of The Total Environment

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Microalgal-based wastewater treatment plants are conceived as low cost and low energy consuming systems. The operation of these plants involves the management of primary sludge and microalgal biomass. The aim of this study is to analyse the anaerobic co-digestion of both by-products in terms of biogas production and contaminants of emerging concern removal. The co-digestion of microalgae and primary sludge (25/75% on a volatile solids basis) was investigated in continuous reactors and compared to microalgae mono-digestion at a hydraulic retention time of 20 days. Results showed how the co-digestion enhanced the anaerobic digestion of microalgal biomass, since primary sludge is a more readily biodegradable substrate, which increased the methane production by 65% and reduced the risk of ammonia toxicity. Regarding the contaminants, musk fragrances (galaxolide and tonalide) and triclosan showed the highest abundance on primary sludge (0.5-25 μg/ g TS), whereas caffeine, methyl dihydrojasmonate and triphenyl phosphate were barely detected in both substrates (<0.1 μg/g TS). The removal of these contaminants was compound-depending and ranged from no removal to up to 90%. On the whole, microalgae mono-digestion resulted in a higher removal of selected contaminants than the co-digestion with primary sludge.

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Section: Introductionmentioning

confidence: 99%

Co-digestion of microalgae and primary sludge: Effect on biogas production and microcontaminants removal

Solé-Bundó

Garfí

Matamoros

et al. 2019

Science of The Total Environment

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“…Indeed, primary sludge is more readily digestible and has less protein content than microalgae [ 15 ], so it could enhance microalgae biodegradability while increasing the OLR. To the best of our knowledge, only a few studies have evaluated the co-digestion of microalgae with primary sludge and always in batch tests [ 15 , 16 ]. Given that some benefits were pointed out (e.g., methane yield increase), these results should be validated better in continuous reactors.…”

Section: Introductionmentioning

confidence: 99%

Strategies to Optimize Microalgae Conversion to Biogas: Co-Digestion, Pretreatment and Hydraulic Retention Time

et al. 2018

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This study aims at optimizing the anaerobic digestion (AD) of biomass in microalgal-based wastewater treatment systems. It comprises the co-digestion of microalgae with primary sludge, the thermal pretreatment (75 °C for 10 h) of microalgae and the role of the hydraulic retention time (HRT) in anaerobic digesters. Initially, a batch test comparing different microalgae (untreated and pretreated) and primary sludge proportions showed how the co-digestion improved the AD kinetics. The highest methane yield was observed by adding 75% of primary sludge to pretreated microalgae (339 mL CH4/g VS). This condition was then investigated in mesophilic lab-scale reactors. The average methane yield was 0.46 L CH4/g VS, which represented a 2.9-fold increase compared to pretreated microalgae mono-digestion. Conversely, microalgae showed a low methane yield despite the thermal pretreatment (0.16 L CH4/g VS). Indeed, microscopic analysis confirmed the presence of microalgae species with resistant cell walls (i.e., Stigioclonium sp. and diatoms). In order to improve their anaerobic biodegradability, the HRT was increased from 20 to 30 days, which led to a 50% methane yield increase. Overall, microalgae AD was substantially improved by the co-digestion with primary sludge, even without pretreatment, and increasing the HRT enhanced the AD of microalgae with resistant cell walls.

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“…The process is justified by the high organic content and adaptation to organic matter turnover under anaerobic conditions, coupled to the ready availability of WWT inocula (Sialve, Bernet & Bernard, 2009). Various aspects of the engineering, kinetics, and the economy of the process, as well as optimization of the inoculum load and substrate load, and algae pretreatment methods have been investigated (Hlavínek et al, 2016; Mudhoo, 2012; Nabarlatz et al, 2013; Ramaraj, Unpaprom & Dussadee, 2016; Samson & Leduy, 1982; Vergara-Fernandez et al, 2008; Ward, Lewis & Green, 2014), but little research on the identity of microorganisms mediating such process has been conducted. Samples were obtained from secondary treatment sludge in the city of Stillwater, OK wastewater treatment plant in September 2015.…”

Section: Methodsmentioning

confidence: 99%

Microbial communities mediating algal detritus turnover under anaerobic conditions

Morrison

Murphy

Baker

et al. 2017

PeerJ

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BackgroundAlgae encompass a wide array of photosynthetic organisms that are ubiquitously distributed in aquatic and terrestrial habitats. Algal species often bloom in aquatic ecosystems, providing a significant autochthonous carbon input to the deeper anoxic layers in stratified water bodies. In addition, various algal species have been touted as promising candidates for anaerobic biogas production from biomass. Surprisingly, in spite of its ecological and economic relevance, the microbial community involved in algal detritus turnover under anaerobic conditions remains largely unexplored.ResultsHere, we characterized the microbial communities mediating the degradation of Chlorella vulgaris (Chlorophyta), Chara sp. strain IWP1 (Charophyceae), and kelp Ascophyllum nodosum (phylum Phaeophyceae), using sediments from an anaerobic spring (Zodlteone spring, OK; ZDT), sludge from a secondary digester in a local wastewater treatment plant (Stillwater, OK; WWT), and deeper anoxic layers from a seasonally stratified lake (Grand Lake O’ the Cherokees, OK; GL) as inoculum sources. Within all enrichments, the majority of algal biomass was metabolized within 13–16 weeks, and the process was accompanied by an increase in cell numbers and a decrease in community diversity. Community surveys based on the V4 region of the 16S rRNA gene identified different lineages belonging to the phyla Bacteroidetes, Proteobacteria (alpha, delta, gamma, and epsilon classes), Spirochaetes, and Firmicutes that were selectively abundant under various substrate and inoculum conditions. Within all kelp enrichments, the microbial communities structures at the conclusion of the experiment were highly similar regardless of the enrichment source, and were dominated by the genus Clostridium, or family Veillonellaceae within the Firmicutes. In all other enrichments the final microbial community was dependent on the inoculum source, rather than the type of algae utilized as substrate. Lineages enriched included the uncultured groups VadinBC27 and WCHB1-69 within the Bacteroidetes, genus Spirochaeta and the uncultured group SHA-4 within Spirochaetes, Ruminococcaceae, Lachnospiraceae, Yongiibacter, Geosporobacter, and Acidaminobacter within the Firmicutes, and genera Kluyvera, Pantoea, Edwardsiella and Aeromonas, and Buttiauxella within the Gamma-Proteobaceteria order Enterobacteriales.ConclusionsOur results represent the first systematic survey of microbial communities mediating turnover of algal biomass under anaerobic conditions, and highlights the diversity of lineages putatively involved in the degradation process.

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Biogas Production from Algal Biomass from Municipal Wastewater Treatment

Cited by 12 publications

References 7 publications

Co-digestion of microalgae and primary sludge: Effect on biogas production and microcontaminants removal

Co-digestion of microalgae and primary sludge: Effect on biogas production and microcontaminants removal

Strategies to Optimize Microalgae Conversion to Biogas: Co-Digestion, Pretreatment and Hydraulic Retention Time

Microbial communities mediating algal detritus turnover under anaerobic conditions

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