Effects of various LED light wavelengths and light intensity supply strategies on synthetic high-strength wastewater purification by Chlorella vulgaris

In this study, our proposed ultraviolet light-emitting diode (UV LED) mosquito-trapping lamp is designed to control diseases brought by insects such as mosquitoes. In order to enable the device to efficiently catch mosquitoes in a wider area, a secondary freeform lens (SFL) is designed for UV LED. The lens is mounted on a 3 W UV LED light bar as a mosquito-trapping lamp of the new UV LED light bar module to achieve axially symmetric light intensity distribution. The special SFL is used to enhance the trapping capabilities of the mosquito-trapping lamp. The results show that when the secondary freeform surface lens is applied to the experimental outdoor UV LED mosquito-trapping lamp, the trapping range can be expanded to 100π·m2 and the captured mosquitoes increased by about 300%.

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Effect of Light Intensity and Quality on Growth Rate and Composition of Chlorella vulgaris

Plants ◽

10.3390/plants9010031 ◽

2019 ◽

Vol 9 (1) ◽

pp. 31 ◽

Cited By ~ 2

Author(s):

Maria N. Metsoviti ◽

George Papapolymerou ◽

Ioannis T. Karapanagiotidis ◽

Nikolaos Katsoulas

Keyword(s):

Growth Rate ◽

Light Intensity ◽

Chlorella Vulgaris ◽

Lipid Content ◽

Growth Rates ◽

Solar Irradiance ◽

White Led ◽

Microalgal Biomass ◽

Nm Range ◽

Effect Of Light

In this research, the effect of solar irradiance on Chlorella vulgaris cultivated in open bioreactors under greenhouse conditions was investigated, as well as of ratio of light intensity in the 420–520 nm range to light in the 580–680 nm range (I420–520/I580–680) and of artificial irradiation provided by red and white LED lamps in a closed flat plate laboratory bioreactor on the growth rate and composition. The increase in solar irradiance led to faster growth rates (μexp) of C. vulgaris under both environmental conditions studied in the greenhouse (in June up to 0.33 d−1 and in September up to 0.29 d−1) and higher lipid content in microalgal biomass (in June up to 25.6% and in September up to 24.7%). In the experiments conducted in the closed bioreactor, as the ratio I420–520/I580–680 increased, the specific growth rate and the biomass, protein and lipid productivities increased as well. Additionally, the increase in light intensity with red and white LED lamps resulted in faster growth rates (the μexp increased up to 0.36 d−1) and higher lipid content (up to 22.2%), while the protein, fiber, ash and moisture content remained relatively constant. Overall, the trend in biomass, lipid, and protein productivities as a function of light intensity was similar in the two systems (greenhouse and bioreactor).

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Treatment of High-Strength Animal Industrial Wastewater Using Photo-Assisted Fenton Oxidation Coupled to Photocatalytic Technology

Water ◽

10.3390/w11081553 ◽

2019 ◽

Vol 11 (8) ◽

pp. 1553 ◽

Cited By ~ 1

Author(s):

Jae Hong Park ◽

Dong Seok Shin ◽

Jae Kwan Lee

Keyword(s):

Light Intensity ◽

Removal Efficiency ◽

Industrial Wastewater ◽

Uv Light ◽

High Strength ◽

Cod Removal ◽

Fenton Oxidation ◽

Optimal Conditions ◽

Experimental Conditions ◽

Animal Wastewater

Animal wastewater is one of the wastewaters that has a color and is difficult to treat because it contains a large amount of non-degradable organic materials. The photo-assisted Fenton oxidation technique was applied to treat animal wastewater, and the optimal conditions of chemical oxygen demands (COD) removal were analyzed according to changes in pH, ferrous ion, H2O2, and ultraviolet (UV) light intensity as a single experimental condition. Experimental results showed that, under the single-factor experimental conditions, the optimal conditions for degradation of animal wastewater were pH 3.5, Fe(II) 0.01 M, H2O2 0.1 M, light intensity 3.524 mW/m2. Under the optimal conditions, COD removal efficiency was 91%, sludge production was 2.5 mL from 100 mL of solution, color removal efficiency was 80%, and coliform removal efficiency was 99.5%.

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Effect of Monochromatic Green LED Light Stimuli During Incubation on Embryo Growth, Hatching Performance, and Hormone Levels

Transactions of the ASABE ◽

10.13031/trans.12485 ◽

2018 ◽

Vol 61 (2) ◽

pp. 661-669 ◽

Cited By ~ 5

Author(s):

Yue Yu ◽

Zhanming Li ◽

Zhengtao Zhong ◽

Shufang Jin ◽

Jinming Pan ◽

...

Keyword(s):

Light Intensity ◽

Green Light ◽

Light Treatment ◽

High Light ◽

Low Light ◽

Dark Treatment ◽

Led Light ◽

Green Led ◽

Serum Hormone ◽

Light Stimuli

Abstract. Previous research indicated improvement of incubation by light stimuli. However, the light source arrangement, usually with irradiation from top to bottom, was inconvenient and high in cost. Among the different light colors, the effects of green LED light stimuli during embryo development were inconclusive. In this study, two LED lamps were installed on both sides of egg trays, and the irradiation was directed from the edges to the middle. The effect of green LED light with various light intensities was investigated. A total of 1408 broiler eggs were randomly allocated to high light (300 lx), middle light (150 lx), low light (50 lx), and dark treatments with four replicates. Embryo weight, body length, organ weight, hatching performance, and serum hormone levels were tested. The results indicated that incubation of the broiler eggs under an appropriate light intensity (low light treatment, 50 lx) of green light significantly increased embryo weight, body length, and hatchability (p < 0.001). According to the serum hormone tests, only the low light treatment significantly increased the thyroxine (T4) levels of the chicks (p < 0.05) at hatching, but the middle and high light treatments slightly decreased the T4 and testosterone (TES) levels of the chicks compared with the dark treatment. Moreover, peak hatching time occurred 12 h earlier in the light treatments compared with the dark treatment. In conclusion, an appropriate light intensity (low light treatment, 50 lx) of LED green light improved embryo growth and hatching performance, but excessive light intensity reduced the positive effects or even produced slight negative effects on the T4 and TES levels of chicks at hatching. Keywords: Embryo, Growth, Hatching performance, Hormone, Monochrome green light.

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