Search results for "Bioreactor"

Mixotrophy in a Local Strain of Nannochloropsis granulata for Renewable High-Value Biomass Production on the West Coast of Sweden

2022

A local strain of Nannochloropsis granulata (Ng) has been reported as the most productive microalgal strain in terms of both biomass yield and lipid content when cultivated in photobioreactors that simulate the light and temperature conditions during the summer on the west coast of Sweden. To further increase the biomass and the biotechnological potential of this strain in these conditions, mixotrophic growth (i.e., the simultaneous use of photosynthesis and respiration) with glycerol as an external carbon source was investigated in this study and compared with phototrophic growth that made use of air enriched with 1–2% CO2. The addition of either glycerol or CO2-enriched air stimulated the…

UCT-MBR vs IFAS-UCT-MBR for Wastewater Treatment: A Comprehensive Comparison Including N2O Emission

2017

In this study the performance (in terms of carbon and nutrient removal) and N2O emission of two plant configurations adopting innovative technologies were investigated. With this regards, an University Cape Town (UCT) membrane bioreactor (MBR) plant and an Integrated Fixed Film Activated Sludge (IFAS) -UCT-MBR plant were monitored. Both plants treat real wastewater under two different values of the influent carbon nitrogen ratio (C/N = 5 mgCOD/mgN and C/N = 10 mgCOD/mgN). Results have shown the highest carbon and nutrients removal efficiencies for the IFAS-UCT-MBR configuration during both the two investigated C/N values. Furthermore, the lowest N2O emission occurred for the IFAS-UCT-MBR.

Evaluation of biomass activity and wastewater characterization in a UCT-MBR pilot plant by means of respirometric techniques

2011

Abstract Over the last two decades, Membrane Bioreactors (MBRs) emerged even more for wastewater treatment, ensuring high removal efficiencies as well as very small footprint requirements. Indeed, in this kind of process, a modification in biomass activity and viability can exist compared to that of a CAS process. In this context, respirometric analysis represents a reliable tool in order to evaluate the actual biomass kinetic parameters, to insert in mathematical models in the design phase, as well as to monitor the biomass viability, especially when these processes are operated with high SRT values. The paper presents some results of respirometric techniques applied for the characterisati…

Detection and prevention of enhanced biological phosphorus removal deterioration caused by Zoogloea overabundance.

2008

A sequencing batch reactor was operated in the conventional anaerobic-aerobic mode for enhanced biological phosphorus removal using acetate as the sole substrate. Despite the nutrients concentrations in the influent being high enough to satisfy the biological requirements, Zoogloea ramigera managed to grow in the system until it had negative effects on the process performance. The excess of exocellular polymeric material produced by this microorganism contributed to a viscous bulking phenomenon and caused important settling problems. The examination of the sludge under the microscope was a valuable tool to diagnose the cause of the imbalance in the process. The strategy adopted to avoid the…

PLLA-BASED SCAFFOLDS FOR OSTEOCHONDRAL TISSUE REGENERATION VIA THERMALLY INDUCED PHASE SEPARATION TECHNIQUE

L’ingegneria tessutale (TE) è una scienza multidisciplinare che mira a progettare e sviluppare sostituti biologici per migliorare, riparare e/o sostituire i tessuti negli organismi umani. Sulla base della tipica triade dell’ingegneria tessutale è incentrato il primo capitolo Scaffold, Source and Signal; lo scaffold funge da struttura tridimensionale, le cellule rappresentano la source mentre il bioreattore fornisce gli adeguati segnali chimico/fisici. In questo lavoro di tesi sono stati presi in considerazione tutti e tre questi aspetti avendo come obiettivo la rigenerazione osteocondrale. La guarigione dei difetti osteocondrali, riguardanti le lesioni della cartilagine che si esten- dono f…

Oxygen transfer performance of unbaffled stirred vessels in view of their use as biochemical reactors for animal cell growth

2012

Cultivation of microorganisms, plants or animal cells requires liquid agitation in order to ensure oxygen and nutrient transfer and to maintain cell suspension. However, In such suspensions both mechanical agitation and sparging aeration can cause cell death. Many studies on animal cell damage due to mechanical agitation and sparging aeration have shown that mechanical damage of freely suspended animal cells is in most cases associated with bursting bubbles at the air–liquid interface (Barrett et al., 2010, Nienow et al., 1996). Gas bubbles are usually generated by direct air sparging to propagate oxygen in a culture suspension. Mechanical agitation may also introduce gas bubbles to the cul…

Technologies for cultivation and exploitation of microalgae in industrial applications

2020

This thesis work is focused on technologies for the development of the microalgal industry. During this 3-years PhD work several themes were addressed. Section 1 consists in a literature review concerning the general features of microalgae, their composition and a description of the photosynthetic process. Furthermore, themes such as biosynthetic pathways, growth kinetics, microalgae cultivation and their applications are reviewed. Section 2 focuses on the genetic manipulation of microalgae aimed at producing a vitamin B12-enriched food supplement. In this case, the human intrinsic factor gene, was inserted in the genome of the microalgae Chlamydomonas reinardhtii in order to integrate new …

<em>Saccharomyces boulardii</em>: probiotic yeast for craft beer production, growth analysis and biovolume estimation

2018

In recent years, an increase in the consumer interest has been observed for craft beers, which are unpasteurized and unfiltered. Thus, the use of probiotic starters remaining in the craft beers could significantly increase health benefits. Here, the first study on the use of the probiotic Sacharomyces boulardii (Sb) yeast as single starter for craft brewing at 20 L scale is presented. The probiotic biomass growth was studied in bioreactor batch culture and modelled by the logistic and Gompertz equations. Finally, the probiotic biovolume of Sb was estimated from microscopy images. All these experiments were compared with those obtained with a commercial Sacharomyces cerevisiae (Sc) yeast str…

Exploring the limits of anaerobic biodegradability of urban wastewater by AnMBR technology

2018

[EN] Anaerobic membrane bioreactors (AnMBRs) can achieve maximum energy recovery from urban wastewater (UWW) by converting influent COD into methane. The aim of this study was to assess the anaerobic biodegradability limits of urban wastewater with AnMBR technology by studying the possible degradation of the organic matter considered as non-biodegradable as observed in aerobic membrane bioreactors operated at very high sludge retention times. For this, the results obtained in an AnMBR pilot plant operated at very high SRT (140 days) treating sulfate-rich urban wastewater were compared with those previously obtained with the system operating at lower SRT (29 to 70 days). At 140 days SRT the …

Extreme thermophilic (70°C), VFA-fed UASB reactor: performance, temperature response, load potential and comparison with 35 and 55°C UASB reactors

1999

Abstract The paper evaluates the reactor performance, load potential and temperature response of a 70°C, VFAs-fed UASB reactor, seeded with mesophilic granular sludge. Batch experiments were, in addition, conducted to assess the effect of temperature on the achievable residual VFAs in the 70°C effluent. The performance of similarly-fed and seeded 35 and 55°C UASB reactors was also tested. At a short HRT (2–3 h) and a moderate VLR of 12–20 g COD l−1 d−1, the 70°C UASB achieved 66–74% VFAs removal (acetate and butyrate 84–90%, propionate