A new photobioreactor for continuous microalgal production in hatcheries based on external-loop airlift and swirling flow

This study deals with the scale of a new photobioreactor for continuous microalgal production in hatcheries. The combination of the state-of-art with the constraints inherent to hatcheries has turned the design into a closed, artificially illuminated and external-loop airlift configuration based on a succession of elementary modules, each one being composed of two transparent vertical interconnected columns. The liquid circulation is ensured pneumatically (air injections) with respect to a swirling motion (tangential inlets). A single module of the whole photobioreactor was built-up to investigate how parameters, such as air sparger type, gas flow rate, tangential inlet, column radius and height can influence radiative transfer, hydrodynamics, mass transfer and biological performances. The volumetric productivities were predicted by modeling radiative transfer and growth of Isochrysis affinis galbana (clone Tahiti). The hydrodynamics of the liquid phase was modeled in terms of global flow behavior (circulation and mixing times, Péclet number) and of swirling motion decay along the column (Particle Image Velocimetry). The aeration performances were determined by overall volumetric mass transfer measurements. Continuous cultures of Isochrysis affinis galbana (clone Tahiti) were run in two geometrical configurations, generating either an axial or a swirling flow. Lastly, the definitive options of design are presented as well as a 120 Liter prototype, currently implemented in a French mollusk hatchery and commercialized

Development of a novel user-friendly platform to couple light regime characterization with particle tracking - cells' light history determination during phototrophic cultivations

Depending on the light regime inside the photobioreactor (PBR) and the flow pattern verified, cells experience different histories with respect to the light regimes they are exposed to, wavelengths of light absorbed and period of time spent under each specific condition. The high heterogeneity of the radiation field inside the PBR due to absorption and scattering of radiation by microalgae/cyanobacteria cells - and the fluctuating cells' light history (CLH), greatly influence photosynthetic conversion and ultimately biomass productivity. This work presents a relatively low-cost, simple, experimental technique which combines light regime and flow pattern characterization, to determine the CLH inside PBRs. A fibre optic spectrometer and probes were employed for quantitative and qualitative light characterization/mapping inside the PBR in this study a split cylinder airlift photobioreactor (SCAPBR) was used while the flow pattern was determined by means of two perpendicular digital cameras which were used to follow fluorescent alginate particles. Temporal and spatial aspects of light patterns were obtained using a MATLAB algorithm that enables automatic merging and synchronization of the data obtained by those two approaches. This provided information about the average time during which cells are subjected to each light regime and how they alternate between them, thus characterizing their CLH.This research work was supported by the grant SFRH/BPD/98694/2013 (Bruno Fernandes) and SFRH/BD/52335/2013 (Pedro Geada) from Fundação para a Ciência e a Tecnologia (Portugal). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), Project RECI/BBB-EBI/0179/2012 (FCOMP-01-0124-FEDER-027462) and FCT Strategic Project of UID/BIO/04469/2013 and UID/Multi/04423/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

Comparing Nutrient Removal from Membrane Filtered and Unfiltered Domestic Wastewater Using Chlorella vulgaris

The nutrient removal efficiency of Chlorella vulgaris cultivated in domestic wastewater was investigated, along with the potential to use membrane filtration as a pre-treatment tool during the wastewater treatment process. Chlorella vulgaris was batch cultivated for 12 days in a bubble column system with two different wastewater treatments. Maximum uptake of 94.18% ammonium (NH4-N) and 97.69% ortho-phosphate (PO4-P) occurred in 0.2 μm membrane filtered primary wastewater. Membrane filtration enhanced the nutrient uptake performance of C. vulgaris by removing bacteria, protozoa, colloidal particles and suspended solids, thereby improving light availability for photosynthesis. The results of this study suggest that growing C. vulgaris in nutrient rich membrane filtered wastewater provides an option for domestic wastewater treatment to improve the quality of the final effluent

Microalgae production in fresh market wastewater and its utilization as a protein substitute in formulated fish feed for oreochromis spp.

Rapid growing of human population has led to increasing demand of aquaculture production. Oreochromis niloticus or known as tilapia is one of the most globally cultured freshwater fish due to its great adaptation towards extreme environment. Besides, farming of tilapia not only involves small scales farming for local consumption but also larger scales for international market which contributes to a foreign currency earning. Extensive use of fishmeal as feed for fish and for other animals indirectly caused an increasing depletion of the natural resource and may consequently cause economic and environmental unstable. Microalgae biomass seems to be a promising feedstock in aquaculture industry. It can be used for many purposes such as live food for fish larvae and dried microalgae to substitute protein material in fish feed. The microalgae replacement in fish feed formulation as protein alternative seem potentially beneficial for long term aqua-business sustainability. The present chapter discussed the potential of microalgae as an alternative nutrition in fish feed formulations, specifically Tilapia

Evaluation of indigenous marine periphytic Amphora, Navicula and Cymbella grown on substrate as feed supplement in Penaeus monodon postlarval hatchery system

Three isolated marine diatoms (Amphora, Navicula and Cymbella) grown on substrate were evaluated as feed supplement for Penaeus monodon postlarvae (PL) in hatchery system for a period of 19 days without changing water. Specific growth rate (day)1) (0.27 ± 0.0) and survival (%) (56.3 ± 1.8) of PLs were significantly higher (P < 0.05) in treatment tanks when compared with the control (0.20 ± 0.0; 36.0 ± 1.5, respectively). Shrimp PLs reared in substrate-based tanks had significantly higher (P < 0.05) levels of protein, lipid (521.0 ± 7.0; 304.0 ± 2 g kg)1 dry weight, respectively), ecosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)(189.0 ± 2.0; 176.0 ± 2 g kg)1 of total fatty acid, respectively) than the control (435.0 ± 22.0; 258.0 ± 22 g kg)1 dry weight; 172.0 ± 5.0; 152 ± 2 g kg)1 total fatty acid, respectively). The periphytic diatoms contained protein and lipid (430–490; 230–260 g kg)1 dry weight, respectively), EPA (30–150 g kg)1 of total fatty acids), DHA (20–30 g kg)1 of total fatty acids) and nine essential amino acids. The results showed that isolated marine periphytic diatoms grown on substrate could be used as feed supplement in enhancing the growth and survival of P. monodon postlarvae

Continuous cultivation of photosynthetic microorganisms: approaches, applications and future trends

The possibility of using photosynthetic microorganisms, such as cyanobacteria and microalgae, for converting light and carbon dioxide into valuable biochemical products has raised the need for new cost-efficient processes ensuring a constant product quality. Food, feed, biofuels, cosmetics and pharmaceutics are among the sectors that can profit from the application of photosynthetic microorganisms. Biomass growth in a photobioreactor is a complex process influenced by multiple parameters, such as photosynthetic light capture and attenuation, nutrient uptake, photobioreactor hydrodynamics and gas-liquid mass transfer. In order to optimize productivity while keeping a standard product quality, a permanent control of the main cultivation parameters is necessary, where the continuous cultivation has shown to be the best option. However it is of utmost importance to recognize the singularity of continuous cultivation of cyanobacteria and microalgae due to their dependence on light availability and intensity. In this sense, this review provides comprehensive information on recent breakthroughs and possible future trends regarding technological and process improvements in continuous cultivation systems of microalgae and cyanobacteria, that will directly affect cost-effectiveness and product quality standardization. An overview of the various applications, techniques and equipment (with special emphasis on photobioreactors) in continuous cultivation of microalgae and cyanobacteria are presented. Additionally, mathematical modelling, feasibility, economics as well as the applicability of continuous cultivation into large-scale operation, are discussed.This research work was supported by the grant SFRH/BPD/98694/2013 (Bruno Fernandes) from Fundacao para a Ciencia e a Tecnologia (Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013. The authors also thank the Project "BioInd Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, REF. NORTE-07-0124-FEDER-000028" Co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDE

L'élevage de la sériole au Japon

L'exploitation des Sérioles par la pêche date de 1490 environ (S. YAMAGUCHI, 1947). Elle s'adres se principalement à Seriola quinqueradiata Temminck et Schlegel, dont les migrations intéressent une grande partie des côtes japonaises. Cette pêche est encore actuellement une des plus importantes activités côtières. L'abondance de Seriola quinqueradiata sur les côtes japonaises, sa croissance très rapide et les facilités d'approvisionnement en jeunes, prédisposaient cette espèce à l' élevage, qui fit son apparition il y a quelques dizaines d'années et se développa rapidement à partir de 1957. Consommé cru, cet animal  connaît une forte demande bien qu'il soit moins apprécié que le thon rouge et certains autres carangidés (Seriola purpurascens, Caranx delicatissimus) dont il est un substitut meilleur marché. Les premières tentatives d'élevage eurent lieu à un moment où la pêche hauturière prenait définitivement l'avantage sur la pêche côtière. Comme c'est souvent le cas, l'élevage avait dans ses débuts les caractères d'un simple stockage du produit vivant de la pêche, en attendant une remontée des cours. Par la suite, les animaux furent capturés plus jeunes et nourris. Actuellement organisé et généralisé, l'élevage de la Sériole dépasse la pêche de la même espèce par le tonnage

Rapport V. 2 Les contributions d'Électricité de France à la valorisation des rejets thermiques

Contributions of Electricité de France to thermal discharge valorization. Contributions of Electricité de France to thermal discharge valorization consist both in elaborating technologies and in transmitting them to professionals. According to those purposes, some experimental operations have been conducted since 1974 on four sites of thermal power stations, both nuclear ant fossil fueled, cooled on sea shore or on river. In this last case, thermal discharge of both once-through and recirculating cooling systems, which present different caracteristics, have been separately evaluated Experimental programs and use of information gathered are under the responsability of associations where concerned professions, technical institutes and Administration are represented. Satisfactory experimental results, increasing participation of professional organizations and full scale operations planned around Dampierre power station make a favorable issue possible in a near future. This trend allows Electricité de France to foresee a gradual decrease of its contributions, in accordance with conditions to be examined.Electricité de France contribue à la valorisation des effluents thermiques de ses centrales en agriculture et aquaculture, tant dans la mise au point des techniques que dans le transfert des résultats aux professions intéressées. Dans ce but, des opérations d'essai et de démonstration ont été conduites depuis 1974 sur quatre sites de centrales thermiques, nucléaires et au fuel, réfrigérées en bord de mer ou sur rivière. Dans ce dernier cas, les effluents thermiques résultant de la réfrigération en circuits ouverts et fermés, qui présentent des caractéristiques différentes, on fait l'objet d'évaluations distinctes. La conduite de ces essais et l'utilisation des enseignements qu'ils ont permis de dégager ont été confiées à des associations où sont représentées les professions intéressées, les instituts techniques compétents, et l'Administration. Le déroulement satisfaisant de certaines opérations, la participation plus active des organisations professionnelles et le lancement prochain d'exploitations en vraie grandeur autour du site de Dampierre, laissent à penser que ces efforts devraient aboutir à terme. Cette perspective permet d'envisager une diminution progressive de l'aide de cet établissement selon des modalités qui sont examinées.Muller-Feuga A. Rapport V. 2 Les contributions d'Électricité de France à la valorisation des rejets thermiques. In: Rejets de chaleur à l'atmosphère. Gestion des calories et hydraulique associée. Compte-rendu des XVIes journées de l'hydraulique. Paris, 16-18 septembre 1980. Tome 2, 1980