Utilizing Lipid-extracted Microalgae Residue for Removal of Methylene Blue from Aqueous Solution

Abstract

Recently, microalgae biomass have been highlighted as the most feasible feedstock for biodiesel production, particularly due to their fast growth rate and they are able to synthesize high content of lipid within their cells. However, after extraction of lipid from the microalgae biomass, the remaining microalgae residues are usually discarded as waste. Thus, the present paper is aimed to recycle the lipid-extracted microalgae residue as adsorbent to remove methylene blue (MB) from aqueous solution. It was found that the microalgae residue could remove 74 % of the MB with biomass dosage of 6.25 g/L, stirring speed of 200 rpm at initial MB concentration of 2 mg/L. The adsorption of MB on microalgae residue fitted well with the pseudo-second order kinetic model and the equilibrium adsorption data indicated that the adsorption behavior followed the Langmuir isotherm.