PROSES PRODUKSI MIKROALGA DALAM PHOTOBIOREAKTOR MINI POND SECARA BATCH UNTUK BAHAN BAKAR BIODISEL

Abstract

Microalgae are microorganisms (size 1-50 m) that uses light energy and water to metabolize CO2 into inorganic compounds CH2O which can be converted into biodiesel. With oil content reaches 30%, microalgae are also potentially be used as biodiesel, which is an alternative energy source. Benefits derived from microalgae biodiesel is a renewable source. The problem in the manufacture of biodiesel from microalgae is not optimal biomass produced. Objectives were to determine the process conditions / parameters in the cultivation of microalgae, determine the best type of nutrients in cultivation, and optimization of biomass as high as possible from microalgae. With this research are expected to know the process conditions / parameters in the cultivation of microalgae, the best type of nutrient, and optimization of biomass as high as possible from microalgae. To achieve the goals of the research a step - step is carried out after the set of tools and materials that make the process of cultivation in the mini-pond. This study uses comparative nutient variables, namely: ammonium bicarbonate, sodium bicarbonate, and NPK fertilizer and the composition of Chlorophyta in the culture medium (100, 75, 50, and 25)% of total volume of cultivation. Furthermore, the determination of concentration was carried out by spectrophotometric analysis method. Microalgae growth pattern to the type of nutrients such as ammonium bicarbonate logaritme phase which includes the phase lag, exponential phase, the phase reduction, stationary phase and death phase. The pattern of growth of microalgae with sodium bicarbonate and nutrients NPK showed a pattern quite different and only marginally decreased. Growth of the highest biomass obtained on the type of nutrient ammonium bicarbonate because it contains elements of nitrogen and carbon was followed in succession by the type of sodium bicarbonate and nutrients NPK fertilizer. Result OD culture volume Chlorophyta Chlorophyta with the total volume of 100% higher than the OD cultivating microalgae Chlorophyta culture volume of 75%, 50%, and 25% of total volume. The most optimum harvest time is on day-2, which is in exponential phase.