| Summary: | The objective of this research was to evaluate the fate of aromatic compounds and organic matter in pilot constructed wetlands (CW) treating <i>Pinus radiata</i> and <i>Eucalyptus globulus</i> sawmill industry leachate. Six lab-scale surface flow CW were built and fed in batches. Three CW were fed with <i>P. radiata</i> leachate, while the other three CW were fed with <i>E. globulus</i> leachate. Each group of three CW included two CW planted with <i>Phragmites australis</i> and one unplanted CW as control unit. A stable hydraulic retention time of seven days was maintained in each CW. The organic loading rate was gradually increased in three phases in the CW fed with <i>P. radiata</i> leachate (i.e., from 12 to 19 g COD/m<sup>2</sup>/day) and with <i>E. globulus</i> leachate (i.e., from 14 to 40 g COD/m<sup>2</sup>/day). The operation of the six CWs lasted 98 days. The CW treating <i>P. radiata</i> and <i>E. globulus</i> leachate had a similar performance. The highest performance was obtained by the unplanted CW (approximately 10−20% higher than the planted CW), without significant differences observed between the <i>P. radiata</i> and <i>E. globulus</i> leachate treatment, regarding the removal efficiencies of organic matter and total phenolic compounds. The planted systems were probably affected by the high concentrations of these compounds applied, which probably created a toxic environment hindering the microbial community growth.
|
|---|