Abstract

Energy from natural sources are widely investigated nowadays. Biomass is an alternative source of energy extracted from biological wastes or materials as fuel. Various plants are the sources of bio fuel; however, the downfall of plants is that they require large area to grow for proper product. On the other hand, microalgae are possibly a better source of energy since they require less area for farming and produce greater amount of oil as compared to that derived plants. Botryococcus braunii is a green microalga and is found in natural freshwater reservoirs in colony form. The algae can provide oil at a maximum of 75 percent of their dry weight. In this work, we use ultrasonic waves with the frequencies of 37 and 80 kHz to excite mix culture of algae samples in an ultrasonic bath. Ultrasonic power and exposure time are parameters in this study. The ultrasonic-exposed algae are sampled for photo-taking purpose under a microscope. The photos are then processed using particle analysis to count the number of algae colonies in comparison to the control algae sample. The result shows that the algae display significant growth with the exposure time of 3 and 5 minutes for 37 kHz waves with the ultrasonic power of 54 and 72 W. For 80 kHz, the power of 60, 90, and 120 W also provide significant multiplication of the algae. With exposure period at a 2-day interval we find that the multiplication is twice of that of the control.