Growth performance and phytoremediation ability of Azolla pinnata in produced water

In the present study, effect of produced water on the growth of Azolla pinnata was observed and the phytoremediating ability of the plant was also exploited. A. pinnata was grown in produced water concentrations of 0% (control), 5%, 10%, 15%, 20% and 25%. The plant exhibited reduced growth rate in a concentration dependent order. Toxicity symptoms of produced water on the plant include chlorosis, frond disintegration and eventual death. Produced water exposure resulted in less than 20% growth inhibition in 5-15 % treatment concentrations. The optimum removal efficiency concentration of produced water by A. pinnata was at 10-20%. It was revealed that A. pinnata has low potential for improving the quality of produced water at high concentrations. This study exposed the need for proper produced water treatment and strict monitoring to ensure compliance with standards set by regulatory bodies before its discharge to surface water to mitigate the environmental impacts.