2.2. Plantation and acclimatization
The Typha sp. (about 80e90 cm in height) was collected from
the marshy land of the Malayer County for preliminary planting.
The roots of sampled plants were washed carefully with tap water
to remove the adsorbed soil particles. The process of phytoremediation
with attached growth was initiated through the serial
exposure of sewage starting from a 20% loading rate, which was
increased gradually to 100% at a hydraulic retention time (HRT) of
26 h over a 15 day period. Subsequently, the system continued to
operate for more 35 days until the reduction in the percentage of
chemical oxygen demand (COD) reached a constant level, which
was considered as the acclimatization period