Unlocking the potential of Chlamydomonas sp. for sustainable nutrient removal from POME: A biokinetic investigation

Abstract

This study aimed to assess the capability of Chlamydomonas sp., for the treatment of palm oil mill effluent (POME), with a particular focus on nutrient removal efficacy. Batch cultivation experiments were conducted using Chlamydomonas sp. in bold basal medium (BBM) with varying POME concentrations. Biokinetic coefficients for nutrient removal were determined using the Michaelis-Menten equation. Over 16 days, Chlamydomonas sp. efficiently removed 100 % of ammonium (NH4+) and nitrate (NO3−), 66–89 % of phosphate (PO43−), and 16.7–33.2 % of chemical oxygen demand (COD). Experimental results and biokinetic coefficients highlighted the superior removal of NH4+ and PO43− by Chlamydomonas sp. in POME. For NH4+, the determined coefficients were k = 3.7161 mg NH4+ mg−1 DCW d−1, Km = 217.97 mg L−1, YN = 17.64 mg DCW mg−1 NH4+. For PO43−, the coefficients were k = 2.5413 mg PO43− mg−1 DCW d−1, Km = 131.53 mg L−1, YP = 12.91 mg DCW mg−1 PO43−. Chlamydomonas sp. biomass performed exceptionally well under low NH4+ and PO43− concentrations, requiring minimal nutrient input compared to COD and NO3−. In conclusion, Chlamydomonas sp. shows promise as an efficient and sustainable option for nutrient removal from POME and other wastewater sources, particularly those containing high levels of nitrogen and phosphate.