The Impact Of Dark Intermittent On The Hydrogen Production By Photosynthetic Bacteria

As a key influencing factor in the process of hydrogen production by photosynthetic bacteria,the research on the illumination conditions has been many,such as the effect of light intensity on hydrogen production by photosynthetic bacteria.But the dark cycle research on hydrogen production of photosynthetic bacteria is still rare.Photosynthetic bacteria utilize glucose or small molecule acid substance metabolism of hydrogen production,there must be the optimum dark cycle time to meet the microbial growth and a short rest.So it is very necessary to study the dark cycle time.At the same time,in order to achieve illumination intensity and dark cycle time common under the influence of the best effect on hydrogen production,the design of experiment to dark cycle time and light intensity under the action of hydrogen production by photosynthetic bacteria hydrogen production were investigated.This paper was completed under the auspices of the national "863" plan project "the key technology research and demonstration of biological hydrogen production",which was presided over by the professor Zhang Quanguo.This paper took HAU-M1 photosynthetic bacteria as the research object,and studied the 2000 lux light illumination intensity under different dark cycle time of optical synthetic bacterial hydrogen production of photosynthetic bacterial growth and the influence of the amount of cumulative production of hydrogen.Then this paper studied the influence of sugar concentration and p H value in the process of hydrogen production.To explore the dark cycle time of different light intensity of hydrogen production by photosynthetic bacteria in the process of photosynthetic bacterial growth and hydrogen production effect,this paper studied the change rules of the accumulative amount of hydrogen production and bacterial growth as the growth of dark cycle time under a certain light intensity in the hydrogen production by photosynthetic bacteria.It was also studied in this paper that is photosynthetic bacteria hydrogen production bacteria growth and cumulative hydrogen production with the variation of light intensity growth under the fixed dark cycle time.At last,the effects and feasibility of dark cycle time and light intensity on hydrogen production by photosynthetic bacteria were analysised.The results were as follows:(1)In the hydrogen production by photosynthetic bacteria,dark break may affect the growth of photosynthetic bacteria and the cumulative hydrogen production.In the reactor which provides dark cycle time,the growth rate of bacterial in light period is less than it in dark cycle.So provide dark cycle time is conducive to the growth of photosynthetic bacteria and the cumulative hydrogen production.But it is not conducive to the hydrogen production by photosynthetic bacteria if the dark cycle time is too long.Because the light is not enough for the growth of photosynthetic bacteria and the cumulative hydrogen production is low.So when the illumination is2000 lux,the best dark cycle time is 6h.(2)Dark cycle time to photosynthetic bacterial growth and cumulative hydrogen production,while the cumulative amount of hydrogen production by photosynthetic bacterial growth,but photosynthetic bacteria growth is not enough to decide the size of the amount of cumulative production of hydrogen.When the dark cycle time is determined,during the process of hydrogen production by photosynthetic bacteria,the concentration of bacteria increases with the increase of the light intensity(1000lux-4000lux),and the amount of hydrogen produced increases with the increase of the intensity of light(1000lux-4000lux).When the illumination is determined,Bacterial concentration increases and then decreases with the dark cycle time In the process of hydrogen production by photosynthetic bacteria,and cumulative hydrogen production increases and then decreases with the dark cycle time In the process of hydrogen production by photosynthetic bacteria.(3)When the dark cycle time is 12 h and the light intensity is 1000 lux,the utilization rate of light energy for hydrogen production by photosynthetic bacteria is high,but the amount of hydrogen production is low.When the dark cycle time is 6h and the light intensity is 2000 lux,the cumulative hydrogen production is higher,but the utilization rate of light energy is low.When the dark cycle time is 6h and the light intensity is 2000 lux,it can both ensure that the final total hydrogen production remained at a higher level,but also take advantage of the light energy.So under the condition of light at this time,the hydrogen producing effect is the best.