Biomass generation and biodiesel production from macroalgae grown in the irrigation canal wastewater

Abstract

The wastewater concentration is commonly acceptable for macroalgae growth as this process consumes water and is applicable for bioremediation. Biodiesel’s potential production from freshwater macroalga, Nitella sp., was investigated using batch experiment. Algae were collected from wastewater saturated from irrigation canals. Water quality and algae growth environment characteristics were monitored and evaluated. COD and BOD values were 18.67±4.62 mg/L and 5.40 ± 0.30 mg/L, respectively. The chemical composition contents were high, indicating that water quality and sufficient nutrients could support algae growth. Oil extraction was estimated by the room temperature and heat extraction methods. The biodiesel in room temperature treatment was 0.0383% ± 0.014%, and in heat, extraction treatment was 0.0723% ± 0.029%. The heat extraction treatment yielded a high amount of oil and biodiesel yield. GC/MS, applied to analyze fatty acid methyl esters, revealed that 9-octadecane was a major portion of the substance. The obtained results confirmed that the wastewater contains many elements that can be utilized for dual-mode, i.e., bioremediation and enhanced macroalgae growth for biodiesel production. Thus, macroalgae grown in canal wastewater were highly feasible for use in sustainable biodiesel production.