Decolorization of organic fertilizer using advanced oxidation process and its application for microalgae cultivation

Advanced oxidation by UV/H2O2 was applied for decolorization of liquid fertilizer, and the resulting liquid fertilizer was utilized to the cultivation of microalga Chlorella vulgaris and biodiesel production. [Display omitted] •Advanced oxidation process (AOP) using UV and H2O2 was successfully applied to reduce the dark color of liquid fertilizer.•Comparison of microalgae cultivation was made in the original and AOP-treated liquid fertilizer as a culture medium of microalgae.•AOP-treated medium resulted in increased biomass concentration and lipid content of Chlorella vulgaris during cultivation time. Advanced oxidation using UV radiation in the presence of H2O2 was applied for decolorization of liquid fertilizer and the resulting liquid fertilizer was utilized to the cultivation of microalga Chlorella vulgaris and biodiesel production. The growth of C. vulgaris was enhanced in decolorized medium. The biomass productivity of C. vulgaris in AOP-treated PAL1 reached 124mg/L, which was 2.1 times higher than that in original PAL1, 58mg/L/day. Cellular lipid accumulation was increased in decolorized medium (from 6 to 30%), because fast growing cells consumed nitrogren faster in decolorized medium and thus lipid synthesis was triggered in nitrogen-deficient environment.