Removal of microbial and genetic contaminants from livestock wastewater using chemically enhanced primary treatment for agricultural irrigation

Irrigation water from the livestock farm serves as a key pathway to disseminate microbial and genetic contaminants. In this study, the applicability of chemically enhanced primary treatment (CEPT) to lagoon-derived dairy farm wastewater was evaluated for the removal of microbial and genetic contaminants (i.e., antibiotic resistance genes (ARGs), and antibiotic resistance bacteria (ARB)), as well as conventional pollutants. Significant removal of both intracellular and extracellular ARGs was achieved at FeCl₃ dosages above 3 g/L during CEPT treatment. Furthermore, no total coliforms, E. coli , or cultivable ARB were detected following CEPT treatment at FeCl₃ dosages above 3 g/L. Considering these findings, CEPT is expected to mitigate the adverse effects of microbial and genetic contaminants resulting from agricultural irrigation. Future efforts should focus on optimizing CEPT to enhance its economic efficiency across different conditions. • Chemically enhanced primary treatment (CEPT) of livestock wastewater was evaluated. • Extracellular antibiotic resistance genes (e-ARGs) during CEPT were evaluated. • CEPT effectively removed intracellular ARGs and e-ARGs. • CEPT effectively removed total coliforms and E. coli .