Removal of Phenol from Olive Mill Wastewater in Constructed Wetlands Using Different Bedding Media

The purpose of this study is to examine the removal of phenol from olive mill wastewater in the planted/unplanted constructed wetlands containing filling material at different percentages. Two constructed wetland systems were developed with two CW1 reactors (containing 100% zeolite) and two CW2 reactors (containing 30% zeolite, 49% gravel and 21% sand) on a laboratory scale. Cyperus alternatifolius was used as the plant for both systems. The HRT (Hydraulic Retention Time) was determined as 2.8 days in system CW1 while it was 3 days in system CW2. The mean phenol concentration for the 89 days was 22.89 mg/l. While the phenol removal values of the systems in the planted and unplanted reactors were obtained as 89.65% +/- 2.61 and 83.21% +/- 5.10 for CW1 respectively, they were 74.55% +/- 14.17 and 73.44% +/- 19.07 for CW2 respectively.