Oilfield-produced water as a medium for the growth of Chlorella pyrenoidosa outdoor in an arid region.

Oilfield-produced wastewater (OPW) provided by the local oil industry was used as a medium (without any pre-treatment) for the outdoor cultivation of microalgae Chlorella pyrenoidosa. The effectiveness of algal growth on the produced water treatment has been investigated. The experimental setups were carried out outdoor, under sunlight radiation, using an open system sited in the desert area. The highest biomass concentration was attaining 1.15 ± 0.07 g/L after 21 culture days. FTIR spectroscopy was used to estimate the lipid content in C. pyrenoidosa grown in BG11 and OPW medium. Daytime temperatures fluctuation was between 26 and 31 °C. The average insolation was no less than 10 h per day with maximum solar irradiation of 1036 ± 30 W/m, measured between 12 and 1 p.m. C. pyrenoidosa was found highly capable of removing COD, NH4 + -N, TN, and TP by 89.67%, 100%, 57.14%, and 75.51%, respectively, throughout the cultivation period. Biosorption of toxic heavy metal pollutants such as Cu, Pb, and Cd was also achieved at rates of approximately 73.39, 72.80, and 48.42%. Overall, the achieved result of C. pyrenoidosa-based process was compared to the actual process using activated carbon.