Hydrogen Production by Green Alga GAF99 in Sea Water Bioreactor: III Use of Modeling and Three Dimensional Plot to Investigate Critical Influence of pH

Biohydrogen production by green algae is effected by environmental conditions. The aim of this study was to show the influence of pH on biohydrogen production by Chaetomorpha sp. GAF99, green alga isolated from Gulf of Aqaba, in seawater bioreactor under anaerobic condition. It was possible to generate a model {HP = 40.52896 e (-15x[(T(C)-24.8)2+(pH-8.18)2])} and building three dimensional plot in order to show the critical influence of various pH values on the biohydrogen production by Chaetomorpha sp. GAF99.The results revealed that the model can give significant relationship between biohydrogen production and pH according to ANOVA statistical analysis based on F and P-tests. The model and three dimensional plot obtained in this study showed clearly that the optimum biohydrogen production was recorded at pH values in the range of 8.2 to 8.7.