Batch kinetics of nutrients removal for palm oil mill effluent and recovery of lipid by Nannochloropsis sp

Abstract

Batch experiments were investigated for the effect of initial nutrients concentration of palm oil mill effluent (POME) on nutrients removals, growth rate, and lipid content recovery by Nannochloropsis sp. Bio-kinetic coefficients, k; reaction rate constant, Km, half-saturation constant, and Y, yield coefficient were determined. The concentrations of POME chosen were 0, 20, 40, 60, 80 % diluted with seawater (POME + SW) and Walne’s medium (POME + WM). Nannochloropsis sp. demonstrated the highest specific growth rate (0.39 d−1), maximum cell density (7.93 × 107 cell/mL) and lipid content (61.60 %) in 60 % POME + WM. Chemical oxygen demand (COD) can be removed effectively with k =11.31 mg COD mg−1 DCW d−1, and Km = 3883.04 mgL−1. The highest polyunsaturated fatty acid (PUFA) of microalgae treated in 60 % POME + WM was 59.13 %. For conclusion, 60 % POME + WM medium can be selected for POME remediation for high nutrients removal, growth rate and lipid content recovery.