Development Of Desert Microalgae Tubular Photobioreactor And Correlational Research

Objective:The study has isolated 18 strains of desert microalgae from the Xinjiang desert Shayang to screen out an oil-producing potential of microalgae and also to optimize the most suitable microalgae growth culture medium using response surface method. To design an outdoor scale culture desert microalgae of tubular photobioreactor, and actually processing the install to the tubular photobioreactor; Under the outdoor conditions, a strains of microalgae that have been screened for having oil-producing potential were scale cultured in the triangle bottle and the design of tubular photobioreactor, and in order to establish theoretical basis, the future industrial production of microalgae was measured to persueing the research experiment results that related to culture microalgae.Methods:Weighing method was used to determine biomass of the 18 strains microalgae, with chloroform-methanol method and phosphorylation vanillin method were used for the determination of total lipid content and total lipid concentration of 18 strains desert microalgae, and calculation the total lipid yields. The Plackett-Burman screening experiment and the Central Composite Design optimization experiment were used for valuing the experiment through the optimization microalgae growth of culture medium by response surface methodology, the microalgae biomass and the total lipid concentration in response to a value. Auto CAD2008 mapping software was used to draw the design of main structure diagrams of the outdoor culture desert microalgae of tubular photobioreactor, the installation, and the actual processing. Under the outdoor natural temperature and uncontrollable light intensity conditions, the triangle bottle modeling trial and the designing and processing of tubular photobioreactor experiments were used to determine the related research using the screened oil-producing potential strains obtained from the test. Statistical data was processed by Design-Expert8.0 software and figures were mapped with Origin8.0 software.Results and Conclusions:1. Screen out an oil-producing potential of microalgae from the 18 desert microalgae strains. The comparative analysis of the biomass measurement results showed that the 5 strains of microalgae TLD2A1(650 mg/L), TLD7B-5(600 mg/L),GTD3a-5(580 mg/L),GTD8A1(560 mg/L),(550 mg/L) GTD9c-2 have bigger biomass than others. Through comparative analysis of the total lipid content and total lipid concentration measure results showed that GTD3a-5 algae strains owned the biggest total lipid content(33%) and total lipid concentration(186 mg/L) was also the highest among the 18 strains microalgae. In summary, of all the 18 strains desert microalgae, GTD3a-5 was the microalgae strains screened out for the oil-producing potential. 2. Optimize the most suitable growth culture conditions of GTD3a-5 algae strains. Through the response surface design, biomass and total lipid concentration response value, through the Plackett-Burman screening experiment, three main factors(Na NO3, Ca Cl2.2H2 O, EDTA) that effected algal strains GTD3a-5 of biomass and total lipid concentration that influenced the growth of the algae strains GTD3a-5, and further based on the three main factors futher Central Composite Design optimization experiment was created, finally established the quadratic polynomial mathematical regression model of algae strains GTD3a-5 biomass and total lipid concentration. Through the response surface methodology, the analysis of interaction between various factors indicated that the medium Na NO3 concentration for 150 mg/L, Ca Cl2.2H2 O concentration for 18 mg/L, EDTA concentration for 20 mg/L, can make algae strains GTD3a-5 obtain the largest biomass; main while the concentration of medium Na NO3 for 50 mg/L, Ca Cl2.2H2 O concentration for 18 mg/L, and EDTA concentration for 20 mg/L, algae strains GTD3a-5 can obtain the larges total lipid concentration.3. According microalgae growth characteristics and environmental to design and processing a airlift tubular photobioreactor of desert culture of microalgae for outdoor conditions, that mainly by the light reaction tubular, airlift tubular, gas distribution system and ancillary components such as composition. Under the outdoor conditions, conducted preliminary experiments in triangle bottle and the photobioreactor in the control cultures culture-experiment, results showed that by shading shadow net can ensure desert microalgae normal growth in the outdoor natural temperature and uncontrollable light intensity conditions, continuous seven days normal growth in photobioreactors, growth of microalgae in the tubular photobioreactor design was better than the microalgae that in the triangle bottle.