Behavior of horizontal sub-surface flow wetlands as an alternative for the wastewater treatment contaminated with florfenicol

Abstract

In recent years, the increase in the use and production of antibiotics for the protection of animals has been associated not only with human health problems due to bacterial resistance, but also with environmental problems, which have led to the deterioration of the water resources, since a large part of these are discharged into the environment without any type of treatment. This situation has highlighted the fact that a large part of the antibiotics are not efficiently removed in conventional wastewater treatment plants, being necessary to implement efficient and low-cost treatment alternatives. The evaluation of the removal of the antibiotic florfenicol was carried out using pilot horizontal subsurface flow wetlands, with a hydraulic retention time of 4.2 d, planted with macrophytes (Phragmites australis) and using concentrations of 10, 15, 20 and 25 mg/L of florfenicol. It was concluded that the removal of the antibiotic and the COD was decreasing over time, with a maximum removal percentage of 77.9% of florfenicol and 85.2% of COD during the first days of exposure. The results found allowed to demonstrate that florfenicol was not retained in the granular material of the wetlands, even in the macrophytes and that the predominant removal mechanism was biological degradation.