Comparative Performance of Textile Dye Degradation by Typha domingensis, Phragmites australis and Bolboschoenus glaucus in a Recirculating Horizontal Flow Constructed Wetland

A subsurface recirculating horizontal flow constructed wetland (RHFCW) was developed in a greenhouse. This system was planted with Typha domingensis, Phragmites australis and Bolboschoenus glaucus successively to study their phytoremediation capacity for the degradation of the pollutant Amaranth azo dye. The aim was to identify which species show better potential for dye degradation. Also, changes in the activities of antioxidant enzymes, and their relation to plant defence system against stress were studied. The order of dye removal, from highest to lowest was reported for the three macrophytes as follows: P. australis > T. domingensis > B. glaucus. P. australis outperformed the other two macrophytes for all parameters. It exceeds about 10% for chemical and biological oxygen demand removal values, and 2 to 5% for nitrate, nitrite and ammonium. Whereas enzyme activity evaluated in leaves of the three macrophytes during treatment increases in accordance with the high removal efficiency of amaranth dye. The highest enzyme activity was found in leaves of P. australis. In conclusion, the study demonstrates the interesting role of these plants in phytoremediation, while P. australis is a more suitable plant to degrade amaranth dye solution.