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
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.