Screening And Cultural Optimization Of Oil-rich Microalgae With Disperse Blue Dye Utilizing Characterizaiton

As a new kind of biomass energy, the performance of biodiesel was better than that of fossil fuels,which was friendly to the environment. Microalgae were the promising raw material of biodiesel, with highgrowth rate, high lipid content, good adaptability to the environment, ability of fixing carbon dioxide andso on. Normally, large amounts of water were consumed in the process of Microalgae cultivation. If dyewastewater could be used for the cultivation of microalgae, not only raw material would be provided forbiodiesel and water resources saved, but also dye wastewater would be treated. It was especially importantto Xinjiang, one province lacked of water resources. Disperse blue was one kind of commonly usedanthraquinone dyes. In this work, one microalga was screened in disperse blue dye medium from Xinjiangwater area. It could grow well, accumulat a large amount of lipid and remove dye effectively. Cultureconditions were investigated then, such as inoculation density, light, original pH and concentration of Fe3+.Results were as follows:Nine microalgae strains were isolated from different water areas of Xinjiang. Compared with thegrowth curve, biomass, lipid content, lipid productivity and the remove rate of dye, microalga XJK waschosen with lipid content of26.5%and lipid productivity of3.3mg·L-1·d-1. The removal rate of dye was67.7%on the11th day for microalga XJK. Through morphological and molecular biology methods,microalga XJK was identified and named chlorella sorokiniana XJK. In dye culture medium, biomass andlipid productivity of C. sorokiniana XJK significantly lower than control medium, but lipid content wasrelatively high C. sorokiniana XJK contained nine kinds of fatty acids, among which C16:0and C18:2accounted for68.0%of the total fatty acids. Saturated fatty acids and unsaturated fatty acid content of C.sorokiniana XJK were46.4%and53.6%, respectively, the ratio of them was0.86:1.That is, biodieselproduction by C. sorokiniana XJK had better low temperature fluidity.Cultural conditions were optimized as original pH of8, concentration ratio of ferric ammonium citratesolution and ferric chloride of2:1, transform light(3500lux until stable phase then turned to800lux) andinoculation density of0.15(absorbance). Under optimized condition, biomass, lipid content and dyeremoval rate of C. sorokiniana XJK were256.2mg·L-1,25.5%,7.3mg·L-1·d-1and80.0%, respectively.The dye removal dynamics of C. sorokiniana XJK was accorded with second-order kinetics equation,speculated that disperse blue dye was not only adsorpted but also degradated by C. sorokiniana XJK.