Algae bioremediation of swine and domestic wastewater promotes a reduction of coliforms and antibiotic-resistant bacteria

Abstract

The microbiological load that wastewater may contain is an important factor to consider in wastewater treatment to avoid water bodies contamination and has taken on great relevance due to the possible presence of antibiotic-resistant bacteria. This study investigates the feasibility of bacteria control by phycoremediation treatment using Scenedesmus sp. in two types of wastewater (domestic and swine wastewater). It was determined the cell growth of microalgae culture, and the reduction of total coliforms and enterobacteria load throughout ten days of experiment. In addition, the removal of antibiotic-resistant bacteria was performed using five different antibiotics commonly used in clinical diagnosis: Ampicillin Tetracycline, Ciprofloxacin, Sulfamethoxazole, and Ceftriaxone. The results shown a significant decrease in total coliforms and enterobacteria in the phycoremediation process, it was removed up to 98 % of total coliforms [ from (8.7 ± 2.31) × 10^4 to (1.6 ± 0.17) × 10^3 CFU mL^−1] in swine wastewater and 99 % in domestic wastewater [(3.6 ± 0.31) × 10^5 to (2 ± 0.05) × 10^3 CFU mL^−1]. Significant reduction in the case of sulfamethoxazole-resistant bacteria by microalgae in swine wastewater from [(1.47 ± 0.05) × 105 to (5.3 ± 0.57) × 10^3 ] and domestic wastewater [(4.9 ± 0.15) × 10^4 to (2.9 ± 0.36) × 10^3]. These findings demonstrate the versatility and effectiveness of the phycoremediation system since the general microbial control to most specific of antibiotic-resistant bacteria in wastewater, demonstrating its great potential to reduce the risk of public health issues in urban and rural areas.