ABSTRACT We aimed to evaluate the efficiency of six different horizontal subsurface flow constructed wetlands (HSSF-CWs), with different substrates (gravel and crushed PET bottles), which also varied in relation to the presence and arrangement of plant species (elephant grass and Tifton 85 bermudagrass) in the removal of pollutants from a bulk milk cooling tank (MTWW). Each bed was fed at a flow rate of 0.18 m3 d-1 and average organic load rate (OLR) of 318 kg ha-1 d-1 of BOD5, with hydraulic detention time (HRT) of 1.84 days in the gravel-filled HSSF-CWs (CWS-G) and 2.97 days in the PET-filled HSSF-CWs (CWs-P). The CWs-P were as efficient as the CWs-G in the removal of BOD5, COD, Total-P, and K-Total, being in some cases even more effective (turbidity,... |