Remarkable Removal of Antibiotic-Resistant Bacteria During Dairy Wastewater Treatment Using Hybrid Full-scale Constructed Wetland

Effective treatment of dairy wastewater with efficient removal of antibiotic-resistant bacteria (ARB) is a great challenge for reuse of treated wastewater. Antibiotics are widely used in human and veterinary medicine, and antibiotics misuse has led to occurrence and spread of antibiotic-resistant bacteria (ARB). Reuse of treated wastewater for irrigation is a solution to deal with water shortage in developing countries. One of the major problems of treated wastewater reuse is the possible presence of ARB. Removal of ARB from dairy wastewater using a full-scale hybrid constructed wetland (CW) at Miyagi Prefecture, Japan, was studied. It was well-defined that hybrid CW caused a complete removal of ampicillin-, gentamicin-, kanamycin-, and streptomycin-resistant bacteria resulting in an effluent free of these resistant strains. Additionally, a significant decrease in the number of vancomycin-RB was definite with a final 3.2 log unit decrease in the effluent. This study addressed the remarkable efficiency of a full-scale hybridized CW in Kawatabi, Field Science Center, Tohoku University. It decreased the output of organic matter (COD), total suspended solids (SS), and ammonia-nitrogen. The performance of CW for the removal ARB from dairy wastewater was efficient to minimize the release of these contaminants into the environment and avoid the spread of antibiotic resistance with safe discharge and reuse of treated wastewater. Finally, the current study represents the first report about the assessment of ARB removal during treatment of dairy wastewater using CW.