Optimization and Performance of Covered-Light Structures for Hydrogen Production by Rhodopseudomonas palustris TN1

Abstract

In recent times, hydrogen production from agro-industry wastewaters using photosynthetic bacteria have been widely studied. Most research has been done with various light sources under uncovered-light structure resulting in light energy losses. Aims of this study are the following parameters; type of light source and shaking rate, and the effect on hydrogen production by Rhodopseudomonas palustris TN1. These studies have employed 50 mL vial bottle reactors under experimental conditions of anaerobic-light system, various covered-light structures (rectangular, hexagonal and curved structure), and at room temperature for 96 h via bath process. Glutamate-acetate medium (GA) was also used as a culture medium. Tungsten lamp lighting without shaking rate was found to be the most suitable condition for hydrogen production. Hydrogen production significantly decreased when shaking rate was increased (p £ 0.05). Then, the individual three covered-tungsten light structures with controlled temperature at 30-37 °C was used for hydrogen production. The rectangular structure obtained the highest hydrogen production of 1,100±47.70 mL/L. The hydrogen production cost (calculated based on electricity used only) between the uncovered-tungsten light structure with GA medium (0.05 baht/mL H2 or 0.0016 US dollar/mL H2) and the covered-tungsten light structure with GA medium (0.04 baht/mL H2 or 0.0013 US dollar/mL H2) showed no significant differences (p>0.05).