Phytoremediation of azo dye acid orange 7 with mycrophyte Typha Latifolia sp. using up- flow constructed wetland
Abstract
Combination of aerobic and anaerobic processes in constructed wetlands can
enhance the treatment performance in textile wastewater. This study assessed the
treatment of azo dye Acid Orange 7 (AO7) and nutrients using three laboratory-scale up
flow constructed wetlands (UFCW) with and without supplementary aeration.
Supplementary aeration controlled the size of aerobic and anaerobic zones in the UFCW
reactors as evidenced by the oxidation–reduction potential (ORP) and dissolved oxygen
(DO) profile of the UFCW. This experiment were conducted with two stages. The AO7
removal efficiency was above 70% and 84% for 1
st
and 2
nd
stage in all UFCW reactors
and most of the color was extensively removed in the aerobic region of the UFCW beds
was about 98% and 99%. The intermediates product produced through the breakage of
azo bond were significantly reduced in the UFCW reactors with supplementary aeration.
The results indicated the applicability of the UFCW reactors to the treatment of azo dyecontaining
wastewater. The COD and NH4-N removals in the aerated reactors were about
85% and 94% (1
st
stage); 91% and 88% (2
nd
stage) , respectively. On the other hand, the
COD and NH4-N removals were in the range of 46%-54% and 0%, respectively, in the
non-aerated reactors. The supplementary aeration enhanced the removal efficiencies in
organic matter, NH4-N and aromatic amines in the UFCW reactors.