Hybrid constructed wetlands were tested to see if they could remove antibiotics from treated blackwater. The wetlands were made up of two parts: a horizontal and a vertical flow system. By using these wetlands, the researchers were able to significantly reduce organic matter, nutrients, and pathogens in the water. They found that with specific retention times, the wetlands could remove up to 93% of BOD5, 74% of COD, 50% of total nitrogen, and 61% of total phosphorus. Additionally, the antibiotic ciprofloxacin was detected at the beginning of the horizontal flow wetland but was not found at the end, showing that the wetlands were effective in removing it.