Sustainable cultivation of microalgae with dimming led for energy production

Product Overview

Description

 

 Sustainable cultivation of microalgae with dimming led for energy production

 

Adjustable light intensity & Spectrum Ratio, Easy for lab

 

 

Wavelength	Spectrum	Group ID	Channel	Driver's Address
730nm	730 Red	01	CH1	0x11
white	Warm White		CH2
630nm	630 Red	02	CH1	0x12
430nm	430 Blue		CH2
450nm	460 Blue	03	CH1	0x13
530nm	530 Green		CH2
660nm	660 Red	04	CH1	0x14
395nm	375 UVA		CH2

 

 

 

Microalgae are a type of autotrophic plants that are widely distributed in the ocean and land, have high photosynthetic utilization, and are rich in nutrients. External factors, that is, the living environment, have obvious effects on the growth of microalgae. , Carbon source, organic nutrients and biological factors are the main factors affecting the growth of microalgae.

 

1 Light

Under the condition that temperature and nutrition do not limit the growth of microalgae, the factor that affects the growth of microalgae is light.

1.1 Light source In addition to using artificial light sources, sunlight is the main light source for microalgae cultivation. Both large-scale outdoor cultivation and indoor small-scale cultivation can effectively utilize solar light sources. However, extreme variability is a characteristic of solar light sources, which makes it more difficult to control the optimal light intensity during cultivation. Indoor small-scale cultivation can use artificial light sources such as incandescent lamps or white fluorescent lamps. The temperature generated by incandescent lamps is very high, which can increase the temperature of the culture fluid, and it is not suitable for use when the temperature is high in summer. The use of artificial light sources can better control the light intensity and time, but there is a problem of high cost, so secondary culture is rarely used in production.

 

1.2 Light quality The color of light is light quality, which refers to light of different wavelengths. In the 300-700 nm spectral region, Salina has two absorption peaks at 436 nm and 679 nm and a shoulder at 470 nm. Phaeodactylum tricornutum growth rate under the five different light qualities of red, yellow, blue, white and purple is blue light, purple light, white light, red light and yellow light in order, and the growth constant under blue light is about 0.44 It was only 0.26 under yellow light; the polysaccharide content was the highest under red light after 8 days of cultivation. When the light intensity is lower than 13.20 μmol / (m² · s), the biomass of spirulina is highest under red light.

 

1.3 Penetration of light in cell suspension When light enters algae fluid, due to the scattering and absorption of algae cells, the light intensity decreases rapidly with the increase of depth. The density of algal cells depends on the depth of light input. The lower the density, the deeper the light penetration. The light intensity absorbed by most cells is often insufficient, because at high density, only the superficial cells can absorb the saturated light intensity that can be used for photosynthesis, and the lower cells are actually in "darkness". Emerson and Lewis determine the light absorption in the suspension of Chlorella nucleus, at a concentration of 1 g / L (calculated as DW), within the first centimeter, there are more than 95% of red and blue light and 60% The green light is absorbed; at a concentration of 10 g / L (calculated as DW), most of the light is absorbed within the first millimeter.

 

1.4 Light intensity Light intensity is the intensity of light. Different algae have suitable light intensity. Under a certain light intensity, the amount of oxygen produced by photosynthesis is exactly the same as the amount of oxygen consumed by respiration. The cells can only maintain basal metabolism and cannot grow. At this time, the light intensity is the light compensation point. Different algae have different light compensation points. The light suitable range of algae must be higher than the light intensity of the compensation point, otherwise it cannot grow and reproduce normally.

 

1.5 Light cycle The daily light time is called the sunshine time, also known as the light cycle. It is also necessary to cultivate microalgae using artificial light sources and understand the reasonable sunshine time of the algae under specific conditions. Tian Gongbo et al. (1955) used 6, 12, and 18 h sunshine time to study their effects on the growth of chlorella. It is found that when the sunshine time is short, the growth rate is proportional to the light time; when the temperature is high or the light intensity is low, although the sunshine time is long, the growth rate is proportional to the sunshine time; Under the light time, continue to increase the sunshine time without increasing the growth rate, there is a "light saturation" phenomenon, too strong and too long light will also cause light suppression. If the photo-inhibition time is too long, the chlorophyll in the algae will undergo photolysis and fade, or even become yellowish white. At low temperatures, the light saturationpointis lower, at this time the algae are more susceptible to damage by strong light, and weak light at low temperatures is more beneficial to the growth of microalgae.