scholarly journals Influence of Light Intensity and Temperature on Cultivation of Microalgae Desmodesmus Communis in Flasks and Laboratory-Scale Stirred Tank Photobioreactor

2015 ◽  
Vol 52 (2) ◽  
pp. 59-70 ◽  
Author(s):  
J. Vanags ◽  
L. Kunga ◽  
K. Dubencovs ◽  
V. Galvanauskas ◽  
O. Grīgs

Abstract Optimization of the microalgae cultivation process and of the bioprocess in general traditionally starts with cultivation experiments in flasks. Then the scale-up follows, when the process from flasks is transferred into a laboratory-scale bioreactor, in which further experiments are performed before developing the process in a pilot-scale reactor. This research was done in order to scale-up the process from a 0.4 1 shake flask to a 4.0 1 laboratory-scale stirred-tank photobioreactor for the cultivation of Desmodesmus (D.) communis microalgae. First, the effect of variation in temperature (21-29 ºC) and in light intensity (200-600 μmol m-2s-1) was studied in the shake-flask experiments. It was shown that the best results (the maximum biomass concentration of 2.72 g 1-1 with a specific growth rate of 0.65 g g-1d-1) can be achieved at the cultivation temperature and light intensity being 25 °C and 300 μmol m2s-1, respectively. At the same time, D. communis cultivation under the same conditions in stirred-tank photobioreactor resulted in average volumetric productivities of biomass due to the light limitation even when the light intensity was increased during the experiment (the maximum biomass productivity 0.25 g 1-1d-1; the maximum biomass concentration 1.78 g 1-1).

2021 ◽  
Vol 11 (4) ◽  
pp. 1788
Author(s):  
Thanh-Tri Do ◽  
Binh-Nguyen Ong ◽  
Tuan-Loc Le ◽  
Thanh-Cong Nguyen ◽  
Bich-Huy Tran-Thi ◽  
...  

In the production of astaxanthin from Haematococcus pluvialis, the process of growing algal biomass in the vegetative green stage is an indispensable step in both suspended and immobilized cultivations. The green algal biomass is usually cultured in a suspension under a low light intensity. However, for astaxanthin accumulation, the microalgae need to be centrifuged and transferred to a new medium or culture system, a significant difficulty when upscaling astaxanthin production. In this research, a small-scale angled twin-layer porous substrate photobioreactor (TL-PSBR) was used to cultivate green stage biomass of H. pluvialis. Under low light intensities of 20–80 µmol photons m−2·s−1, algae in the biofilm consisted exclusively of non-motile vegetative cells (green palmella cells) after ten days of culturing. The optimal initial biomass density was 6.5 g·m−2, and the dry biomass productivity at a light intensity of 80 µmol photons m−2·s−1 was 6.5 g·m−2·d−1. The green stage biomass of H. pluvialis created in this small-scale angled TL-PSBR can be easily harvested and directly used as the source of material for the inoculation of a pilot-scale TL-PSBR for the production of astaxanthin.


2005 ◽  
Vol 51 (12) ◽  
pp. 217-226
Author(s):  
C.J. Banks ◽  
S. Heaven ◽  
E.A. Zotova

The effect of accumulated bottom sludge on water column characteristics was studied in two pilot-scale ponds. Parameters measured were ammonia, nitrate, phosphate, COD, suspended solids, dissolved oxygen (DO), temperature and light intensity. The de-sludged pond showed a stronger correlation between DO, light intensity, nutrients and suspended solids with the controlling factor being availability of nitrogen. This was less apparent in the pond with sludge where nutrient levels were higher and more complex mechanisms controlled biomass concentration. Water column characteristics in the two ponds converged rapidly in 7–10 weeks, however, due to accumulation of fresh sludge.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
A. Barros ◽  
H. Pereira ◽  
J. Campos ◽  
A. Marques ◽  
J. Varela ◽  
...  

Abstract Industrial scale-up of microalgal cultures is often a protracted step prone to culture collapse and the occurrence of unwanted contaminants. To solve this problem, a two-stage scale-up process was developed – heterotrophically Chlorella vulgaris cells grown in fermenters (1st stage) were used to directly inoculate an outdoor industrial autotrophic microalgal production unit (2nd stage). A preliminary pilot-scale trial revealed that C. vulgaris cells grown heterotrophically adapted readily to outdoor autotrophic growth conditions (1-m3 photobioreactors) without any measurable difference as compared to conventional autotrophic inocula. Biomass concentration of 174.5 g L−1, the highest value ever reported for this microalga, was achieved in a 5-L fermenter during scale-up using the heterotrophic route. Inocula grown in 0.2- and 5-m3 industrial fermenters with mean productivity of 27.54 ± 5.07 and 31.86 ± 2.87 g L−1 d−1, respectively, were later used to seed several outdoor 100-m3 tubular photobioreactors. Overall, all photobioreactor cultures seeded from the heterotrophic route reached standard protein and chlorophyll contents of 52.18 ± 1.30% of DW and 23.98 ± 1.57 mg g−1 DW, respectively. In addition to providing reproducible, high-quality inocula, this two-stage approach led to a 5-fold and 12-fold decrease in scale-up time and occupancy area used for industrial scale-up, respectively.


2021 ◽  
Vol 1053 (1) ◽  
pp. 012106
Author(s):  
N N Fathonah ◽  
S Madhania ◽  
T Nurtono ◽  
S Winardi

Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 264 ◽  
Author(s):  
Su Bin Yeom ◽  
Du Hyung Choi

An approach combining quality by design (QbD) and the discrete element method (DEM) is proposed to establish an effective scale-up strategy for the blending process of an amlodipine formulation prepared by the direct compression method. Critical process parameters (CPPs) for intermediate critical quality attributes (IQAs) were identified using risk assessment (RA) in the QbD approach. A Box–Behnken design was applied to obtain the operating space for a laboratory-scale. A DEM model was developed by the input parameters for the amlodipine formulation; blending was simulated on a laboratory-scale V-blender (3 L) at optimal settings. The efficacy and reliability of the DEM model was validated through a comparison of simulation and experimental results. Change of operating space was evaluated using the validated DEM model when scaled-up to pilot-scale (10 L). Pilot-scale blending was simulated on a V-blender and double-cone blender at the optimal settings derived from the laboratory-scale operating space. Both pilot-scale simulation results suggest that blending time should be lower than the laboratory-scale optimized blending time to meet target values. These results confirm the change of operating space during the scale-up process. Therefore, this study suggests that a QbD-integrated DEM simulation can be a desirable approach for an effective scale-up strategy.


Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1391
Author(s):  
Shugeng Feng ◽  
Shengjun Xu ◽  
Xupo Zhang ◽  
Rui Wang ◽  
Xiaona Ma ◽  
...  

Water pollution caused by various eutrophic nutrients such as nitrogen (N) and phosphorus (P), such as outbreaks of eutrophication in rivers and lakes, has become a serious environmental problem in China. Such problems have spurred extensive studies aiming at finding environmentally friendly solutions. Various constructed wetlands (CWs), planted with different macrophytes, have been considered as environmentally safe technologies to treat various wastewaters for several decades. Due to their low energy and operational requirements, CWs are promising alternative solutions to water eutrophication problems. Within the CWs, macrophytes, sediments, and the microbial community are indispensable constituents of such an ecosystem. In this study, a laboratory-scale surface flow CW (LSCW) was constructed to investigate the effects of two different plants, Eichhornia (E.) crassipes (Mart.) Solms and Myriophyllum (M.) aquaticum, on the removal of eutrophic N and P. The results showed that both plants could significantly reduce these nutrients, especially ammonium (NH4+), and LSCW planted with M. aquaticum performed better (82.1% NH4+ removal) than that with E. crassipes (66.4% NH4+ removal). A Monod model with a plug flow pattern was used to simulate the relationship of influent and effluent concentrations with the kinetic parameters of this LSCW. Based on the model, a pilot-scale surface flow CW (PSCW) was designed, aiming to further enhance N and P removal. The treatment with M. aquaticum and polyethylene materials showed the best removal efficiency on NH4+ as well as on total nitrogen and phosphorus. In general, the enlarged PSCW can be a promising solution to the eutrophication problems occurring in aquatic environments.


Eksergi ◽  
2016 ◽  
Vol 13 (2) ◽  
pp. 1
Author(s):  
Sri Sukadarti ◽  
Sri Wahyu Murni ◽  
M.M. Azimatun Nur

Waste of Virgin Coconut Oil (VCO) industries has a high value of Chemical Oxygen Demand (COD), it is therefore a problem for the environment. This waste contains organic materials such as oil, proteins, carbohydrates and some minerals, that potentially to be used for the cultivation of blue-green algae Spirulina plantesis.  Spirulina plantesis is an excellent source of phycocyanin. The Phycocyanin has anti-aging, anti-oxidant and anti-inflammatory properties, it is therefore considered useful. This research is aimed to study the effects of the addition of urea and light intensity on the growth of Spirulina, the concentration of phycocyanin and decreasing of COD value. Spirulina platensis was cultivated in a closed photobioreactor with an air flow for 7 days.  The light intensity was varied as follows 5000 lux, 6000 lux, 7000 lux and 8000 lux, and the addition of urea as nutrients was also varied as follows 40 ppm, 50 ppm, 60 ppm and 70 ppm.  This research indicated that the optimum condition was obtained at the addition of urea of 70 ppm, light intensity  of 6000 lux. This research resulted μmax of 1,1375day-1 , the biomass  productivity of 0,0423 g/l/day,  biomass concentration of   0,1734 g/l  and  phycocyanin concentration of 5,047%. The largest of COD removal is was 98,06% and the COD value of  280 mg/l was finally achieved.


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