Effects Of Phosphate And Carbonate On Hydrogen Production By Simultaneous Saccharification And Fermentation Of Photosynthetic Bacteria

With the depletion of global resources and irrational use of energy,the destruction of the environment has increased,and hydrogen energy has become increasingly attractive as an ideal alternative energy source.Photosynthetic biohydrogen production can be organically combined with solar energy utilization,hydrogen energy development,and organic waste treatment,and has more potential for development with its low-cost,low-energy green energy production technologies.In this paper,the effects of phosphate and carbonate on hydrogen production by simultaneous saccharification and fermentation of photosynthetic bacteria were studied under different initial p H conditions with corn straw as raw materials,so as to obtain the best hydrogen production conditions,and to provide further reference for improving the hydrogen production capacity of the system and reducing the cost of hydrogen production.The results showed that:Phosphate has a significant effect on the hydrogen production of photosynthetic bacteria.Phosphate can promote the hydrogen production of photosynthetic bacteria in a certain concentration range,too high or too low concentration have inhibitory effect on hydrogen production.At initial p H values of 6,7 and 8,the maximum hydrogen yield was obtained at a phosphate concentration of 4 mmol/L,which were 63.09±0.38,62.23±0.84 and 58.97±0.68 m L/g TS,respectively.Compared with the control group,it increased significantly by 45.94%,20.46% and 24.83%,respectively(P<0.05).Phosphate can effectively buffer the p H of the reaction system.The final p H value of the added phosphate was significantly different from the control group(P<0.05),and the final p H value of the reaction system gradually increased with the increase of phosphate concentration.The appropriate concentration of phosphate can increase the hydrogen production potential and the maximum hydrogen production rate of photosynthetic bacteria,and shorten the hydrogen production delay time.Carbonate has a significant effect on the hydrogen production of photosynthetic bacteria.Carbonate can promote the hydrogen production of photosynthetic bacteria in a certain concentration range,too high or too low concentration have inhibitory effects on hydrogen production.At initial p H values of 6,7 and 8,the maximum hydrogen yields were obtained at phosphate concentration of 6,4 and 4 mmo/L respectively,which were 62.36±2.26,67.20±0.72,and 62.15±0.49 m L/g TS,respectively.Compared with the control group,it increased significantly by 44.25%,30.08%,and 31.56%,respectively(P<0.05).Carbonate can effectively buffer the p H value of the reaction system.The final p H value of the added carbonate was significantly different from the control group(P<0.05),and the final p H value of the reaction system gradually increased with the increase of concentration.At initial p H values of 6 and 7,the appropriate concentration of carbonate can increase the hydrogen production potential and the maximum hydrogen production rate of photosynthetic bacteria,and shorten the hydrogen production delay time.At initial p H values of 8,the appropriate concentration of carbonate can increase the hydrogen production potential of photosynthetic bacteria,but it will reduce the maximum rate of hydrogen production and prolong the hydrogen production delay time.