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Author Cabrera, F.; Torres, A.; Campos, J.L.; Jeison, D.
Title Effect of Operational Conditions on the Behaviour and Associated Costs of Mixed Microbial Cultures for PHA Production Type
Year 2019 Publication Polymers Abbreviated Journal Polymers
Volume 11 Issue 2 Pages 14 pp
Keywords PHA; mixed microbial cultures; bioplastics; feast-famine; cost
Abstract Massive production and disposal of petrochemical derived plastics represent relevant environmental problems. Polyhydroxyalkanoates (PHA) are a renewable alternative that can even be produced from wastes. The production of PHA from acetate using mixed microbial cultures was studied. The effect of two key operational conditions was evaluated, i.e., substrate concentration and cycle length. The effects of these factors on several responses were studied using a surface response methodology. Several reactors were operated under selected conditions for at least 10 solids retention times to ensure stable operation. Results show that conditions providing higher PHA content involve lower biomass productivities. This has a great impact on biomass production costs. Results suggest then that PHA content alone may not be a reasonable criterion for determining optimal conditions for PHB production. If production costs need to be reduced, conditions that provide a lower PHA content in the selection reactor, but a higher biomass productivity may be of interest.
Address [Cabrera, Francisco; Torres, Alvaro] Univ La Frontera, Dept Chem Engn, Ave Francisco Salazar 01145, Temuco 4780000, Chile, Email: f.cabrera01@ufromail.cl;
Corporate Author Thesis
Publisher Mdpi Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2073-4360 ISBN Medium
Area Expedition Conference
Notes WOS:000460296000005 Approved
Call Number UAI @ eduardo.moreno @ Serial 986
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Author Cabrera, F.; Torres-Aravena, A.; Pinto-Ibieta, F.; Campos, J.L.; Jeison, D.
Title On-Line Control of Feast/Famine Cycles to Improve PHB Accumulation during Cultivation of Mixed Microbial Cultures in Sequential Batch Reactors Type
Year 2021 Publication International Journal of Environmental Research and Public Health Abbreviated Journal Int. J. Environ. Res. Public Health
Volume 18 Issue 23 Pages 12611
Keywords PHB; bioplastics; SBR; dissolved oxygen; feast; famine
Abstract Production of polyhydroxyalkanoates (PHA) has generated great interest as building blocks for bioplastic production. Their production using mixed microbial cultures represents an interesting alternative, since it enables the use of organic wastes as a carbon source. Feast/famine strategy is a common way to promote selection of microorganisms with PHA accumulation capacity. However, when using waste sources, changes in substrate concentration are expected, that may affect performance and efficiency of the process. This study showed how the dissolved oxygen level can be used for online control of the cycle time, ensuring that the desired feast/famine ratio is effectively applied. An operation strategy is presented and validated, using sequential batch reactors fed with acetate as the carbon source. Production of polyhydroxybutyrate (PHB) was studied, which is the expected type of PHA to be synthetized when using acetate as substrate. Two reactors were operated by applying the proposed control strategy, to provide F/F ratios of 0.2 and 0.6, respectively. A third reactor was operated with a fixed cycle time, for comparison purposes. Results showed that the reactor that operated at an F/F ratio of 0.6 promoted higher biomass productivity and PHB content, as a result of a better use of available time, preventing unnecessary long famine times. The application of the tested strategy is a simple a reliable way to promote a better performance of feast/famine-based bioreactors involving mixed microbial cultures for PHB production.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1660-4601 ISBN Medium
Area Expedition Conference
Notes WOS:000734924900001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1523
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Author Cofre, C.; Campos, J.L.; Valenzuela-Heredia, D.; Pavissich, J.P.; Camus, N.; Belmonte, M.; Pedrouso, A.; Carrera, P.; Mosquera-Corral, A.; Val del Rio, A.
Title Novel system configuration with activated sludge like-geometry to develop aerobic granular biomass under continuous flow Type
Year 2018 Publication Bioresource Technology Abbreviated Journal Bioresour. Technol.
Volume 267 Issue Pages 778-781
Keywords Continuous flow; Feast/famine length ratio; Granular biomass; Two tanks system
Abstract A novel continuous flow system with “flat geometry” composed by two completely mixed aerobic tanks in series and a settler was used to promote the formation of aerobic granular sludge. Making similarities of this system with a typical sequencing batch reactor (SBR), for aerobic granules cultivation, the value of the tank 1/tank 2 vol ratio and the biomass recirculation rate would correspond with the feast/famine length ratio and the length of the operational cycle, respectively, while the settler upflow liquid velocity imposed would be related to the settling time. From the three experiments performed the best results were obtained when the tank 1/tank 2 vol ratio was of 0.28, the sludge recycling ratio of 0.25 and the settler upflow velocity of 2.5 m/h. At these conditions the aggregates had settling velocities between 29 and 113 m/h, sludge volume index at 10 min (SVI10) of 70 mL/g TSS and diameters between 1.0 and 5.0 mm.
Address [Cofre, C.] Univ Tecn Federico Santa Maria, Chem & Environm Engn Dept, Ave Espana 1680, Valparaiso, Chile, Email: jluis.campos@uai.cl
Corporate Author Thesis
Publisher Elsevier Sci Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0960-8524 ISBN Medium
Area Expedition Conference
Notes WOS:000441876100094 Approved
Call Number UAI @ eduardo.moreno @ Serial 911
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