Optimization Of Microalgae Growth Using Capped Total Energy Consumption Method

In recent years,the burning of fossil fuels has led to increasingly serious environmental problems.Microalgae have been paid more and more attention because of its ability to solve the problems mentioned above.At present,the economic problem is still the key to restrict the large-scale application of microalgae.The capped total amount principle has shown its unique value in the carbon emissions trading system.Inspired by that,this study attempts to introduce the capped total amount principle to the cultivation of microalgae,and improve the economic efficiency of microalgae biotechnology.To achieve the above idea,this study constructed a new-type microalgae culture system,and based on the capped total amount principle,designed the capped total light-energy-consumption method.The comparison research of traditional method and capped total light-energy-consumption method.Firstly,under the traditional method,the effects of white light-emitting diodes?LEDs?with different light intensities at photoperiod of 18:6 h on Chlorella pyrenoidosa growth were investigated.the microalgae exhibited the highest growth rate 89.0mg L^-1 d^-1 and growth efficiency 97.8 mg L^-1 KWh^-1 at 110 and 90?mol m^-2 s^-1,respectively.The asynchronous phenomenon between growth rate and growth efficiency was found.With the increase of light intensity,more power consumption will bring less biomass output,which may be the direct cause of the phenomenon.And then,using the capped total energy consumption method,the influences of LEDs?red,blue and white?under capped daily energy consumption(0.80 KWh d^-1)with combinations of electric power?33.3,44.4 and 66.6 w?and photoperiod?24:0,18:6 and 12:12 h?were further investigated.The highest growth efficiency 106.4 mg L^-1 KWh^-11 and growth rate 85.1 mg L^-1 d^-1 were both obtained under white-33.3 w-24 h,and growth efficiency and growth rate were simultaneously improved 1.1times.The results suggested that growth rate and growth efficiency could be improved simultaneously,and this effort may have a vital significance for the large-scale microalgae production.The order of growth efficiency under different LEDs were white>blue>red.The generation of chlorophyll was more sensitive to light combinations under blue.