Comparative studies on phycoremediation efficiency of different water samples by microalgae

The bright potential of microalgae as a biological phycoremediation agent could not only treat wastewater but also be feasible to be utilized as raw material for third generation biofuel. However, the ability of microalgae in treating different water sources varies owing to different water characteristics, thus influencing the cost of water treatment. This study aims to screen the best microalgae including Chlorella vulgaris (CV), Characium sp. (UKM1), Chlorella sp. (UKM2), Chlorella sp. (UKM8) and Scenedesmus sp. (UKM9) in performing phycoremediation efficiency to treat different water sources (palm oil mill effluent (POME), municipal wastewater and polluted surface water). The findings show that all microalgae could grow in all water sources with the maximum specific growth rate in the range of 0.24–0.44 day⁻¹. Results indicated that POME was the best water source for phycoremediation with highest removal of chemical oxygen demand (COD), total nitrogen (TN) and total phosphorus (TP) depending on the microalgae species with removal percentage in the range of 50 to 71 %. Principal component analysis (PCA) results showed that microalgae worked best in reducing COD, TN and TP in POME while the highest lipid produced by UKM9. In conclusion, POME provides substantial nutrients to support microalgae growth with an accumulation of metabolites that can be beneficial for further applications.