Nine constructed wetlands (SACESHs) were built on a pilot scale (1.5 m long, 0.5 wide and 0.4 m deep), grown with Typha sp. and Alternanthera phyloxeroides, and operated under different organic loads in the treatment of wastewater of coffee processing (ARC). Three systems received no ARC pre-treatment, three received ARC with correction of pH and nutritional correction, and the last three received the effluent of filters used in the anaerobic treatment of ARC that had the pH and nutrient content corrected. The results showed that the increase in the rate of surface charge of the constituents of the ARC provided the decrease in efficiency of removal of all SACESHs evaluated. The hydraulic detention time of more than 100 h provided higher efficiencies in the removal of COD (SAC*1, SAC F1 and SAC F2) and BOD (SAC1, SAC*1, SAC F2 and SAC F3) than hydraulic detention times of approximately 60 h implemented in the early stages of the experiment. Among SACESHs the SAC F1, which received the lowest organic load (1500 kg ha-1 d-1 of COD), showed a satisfactory performance with regard to the removal of BOD (63%), COD (85%) and phenolic compounds (65%).
constructed wetlands; wastewater agro-industry; coffee; phenolic compounds; organic matter
