الفهرس 
ُEnglish CoverOnly 14 pages are availabe for public view
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Abstract
The effect of exposing the fungi (yeast) Saccharomyces cerevisiae to laser source in the presence of graphitic carbon nitride (g-C3N4) with different concentrations on bioethanol production was investigated through the implementation of a batch anaerobic system and using potato wastes. Dichromate test was used as a quantitative analysis for determination of the yield of bioethanol production. The advantages of this test were the appearance of green color indicating the identification of ethanol by bare eye and the ease to calculate the yield of bioethanol production through UV-Visible spectrophotometry. It was shown that as the concentration of g-C3N4 increased, the bioethanol was increased. The control sample (0.0 mg of g-C3N4) showed only a 4٪ yield of bioethanol; however, by adding 150 mg to the potato biowaste medium, 22.61٪ of ethanol was produced. On the other hand, laser irradiations (blue and red) as influencing parameters were studied in the absence as well as in the presence of g-C3N4 with the aim to increase the yield of bioethanol production. It was determined that the laser irradiation can trigger the bioethanol production (in case of red: 13.12 ٪and in case of blue: 16.44٪ yields, respectively) compared to the control sample (in absence of g-C3N4). However, by adding different concentrations of g-C3N4 from 5 mg to 150 mg, the yield of bioethanol was increased as follows: in case of red: 56.11٪ and, in case of blue: 56.77٪, respectively. This implies that it is necessary to use laser irradiation in presence of g-C3N4. This phenomenon happened due to the unique physical characteristics of gC3N4 which is known as an electron-rich semiconductor. It was found that using fungi and exposing it to the blue laser diode source with a wavelength of 450 nm and a power of 250 mW for duration of 30 min with the presence of 150 mg L-1 of graphitic carbon nitride nanosheets (gC3N4) delivered the highest bioethanol yield from potato processing wastes.