Investigating the efficiency of biological treatment process of oil pollutants using mix of <i>Scenedesmus obliquus</i> and <i>Chlamydomonas reinhardtii</i> algae: A case study

Abstract

The studies on polycyclic aromatic hydrocarbons (PAHs) occurrence, distribution, health risk, and effect of them on aquatic environments are limited in worldwide. To cope with this critical challenge, the process of eliminating oil compounds and growing algae were investigated by conducting various experiments in an artificial environment of petroleum that were called M1, M2 and M3 (0.05 mg/L, 1.5 mg/L, 2.5 mg/L concentration of oil per 100 mg/L distilled water) using mix cultivating Scenedesmus.obliquus and Chlamydomonas reinhardtii algae. In this matter, the highest rate of the growth of algae was significantly reported in M2 treatment (P < 0.01). Moreover, the percentage of removal of all light petroleum hydrocarbons in M1 treatment was 100% on day 14 of cultivation (P < 0.05). Compared to light hydrocarbon compounds, 8 heavy combinations with 97.33% in the concentration of 0.5 g/100 mL and 85.66% in the initial concentration of 1.5 g/100 mL and 73.66% at the initial concentration of 2.5 g/100 mL of crude oil were eliminated by S. obliquus and C. reinhartii algae (P < 0.01). Finally, the experimental results revealed that in terms of the potential for nutrient removal, the cultivation of mixing two algae S. obliquus and Chlamydomonas reinhardtii in wastewater, hydrocarbon compounds, and water quality and biomass production, can be distinguished as some acceptable options to exploit in the biological treatment of contaminated aquatic environments.

Keywords

• algae
• scenedesmus obliquus algae
• chlamydomonas reinhardtii
• oil wastewater
• biological purification
• nutrient removal