• KSBB Journal
• /
• v.15 no.1
• /
• pp.14-21
• /
• 2000

In this study, algae cultivation using the photobioreactor has been applied to remove the nitrogen and phosphorus compounds in the wastewater of the livestock industry. The optimal ratio of nitrate and ortho-phosphate concentration was found for the enhancement of removal efficiency. To achieve the high density culture of algae, the photobioreactor consisted of optical fibers wes developed to get the sufficient light intensity. The light could be illuminated uniformly from light source to the entire reactor by the optical fibers. The structured kinetic model was proposed to describe the growth rate, consumption rate of nitrates and ortho-phosphates in algae culture. The self-organizing fuzzy logic controller incorporated with genetic algorithm was constructed to control the semi-continuous wastewater treatment system. The proposed fuzzy logic controller was applied to maintain the nitrated concentration at the given set-point with the control of wastewater feeding rate. The experimental results showed that the self-organizing fuzzy logic controller could keep the nitrate concentration and enhance algae growth.

• Journal of the Korean Society for Precision Engineering
• /
• v.28 no.2
• /
• pp.125-132
• /
• 2011

This paper describes current status and future prospects of the mass production of microalgae biomass. Microalgae have attracted considerable attention since they not only effectively fix $CO_2$ gas during their metabolic process but also have the great potential to be utilized for producing valuable substances as a kind of efficient light-harvesting cell factories. In this review, we outline various types of photobioreactors employed for mass production of biomass by culturing microalgae in a well controlled way and give an overview about the present state of affairs, both domestic and international, in the field of the microalgal culturing technologies.

• Applied Chemistry for Engineering
• /
• v.22 no.3
• /
• pp.301-307
• /
• 2011

Optimal culture conditions of Spirulina platensis NIES 39 have been established using different types of light sources. Several types of photobioreactors were designed and the increase of biomass, the amount of $CO_2$, fixation and the production of chlorophyll content were studied. The result revealed that the input conditions of a 10 min period per 4 h at the condition of 5% $CO_2$ and 0.1 vvm, were excellent in the growth. The growth showing the maximum biomass accumulation is limited to 1.411 g/L when using the fluorescent bulb and the low powered surface mount device (SMD) type LEDs which were equipped-inside in the photobioreactor. However, the biomass exceeded up to 1.758 g/L level when a high powered red LED (color temperature : 12000 K) photobioreactor system was used. The $CO_2$ fixation speed and rate were increased. Although the total production of chlorophyll content undergoes a proportional increase in the biomass, the net content per dry cell weight (DCW) showed the higher production with a blue LED (color temperature : 7500 K) light than that of any other wavelengths. The carbon dioxide loss was marked as 0.15% of the inlet gas (5% $CO_2/Air$, v/v) at the maximum biomass culture condition.

• KSBB Journal
• /
• v.19 no.4
• /
• pp.257-262
• /
• 2004

Recently, there is a growing interest in microalgae and the use of microalgae focused on the production of various high value metabolite used in food, pharmaceuticals and cosmetics. The key limiting factor in high density algal cultivation is the light and algal growth is defined by light intensity and light penetration depth into the culture medium. The effect of light with various light paths, S/V ratios, light intensities, and 50% duty cycle on the growth of microalgae was examined to enhance microalgal biomass productivity and photosynthetic efficiency. We confirmed that the utilization of efficient light energy was obtained from 4 cm of diameter, 57.6% of S/V ratio, 62 ${\mu}$mol/㎡/s of light intensity.

• Applied Chemistry for Engineering
• /
• v.21 no.3
• /
• pp.272-277
• /
• 2010

To replace current expensive photobioreactor, this study was conducted to develop low-cost photobioreactor made of polyethylene bag. In previous study, optimal culture conditions of Spirulina platensis NIES 39 have been established, and based on these, the study of biological carbon dioxide fixation has been conducted. The maximum growth was the biomass 2.677 g/L at conditions of 10% $CO_2$, 0.1 vvm. It was shown that $F_{CO_2}$ was 4.056 g $CO_2$/L and $R_{CO_2}$ was 0.312 g $CO_2$/L/day. But, compared with the data at conditions of 5% $CO_2$, 0.1 vvm, $FE_{CO_2}$ was shown 52.372% which is half of it. Regarding the effect of $CO_2$ following illumination, the growth revealed that the input conditions, for 10 min per 3 h, were excellent in the light. $CO_2$ in absent light. $CO_2$ concentration and flow rate were 5% $CO_2$, 0.1 vvm, respectively. Finally, the addition of $CO_2$ was ineffective in the absence of light.