Enhancing Triclosan Removal from Wastewater Using Free and Immobilized Bacteria

Abstract

Triclosan (TCS), a widely used pharmaceutical and personal care product (PPCP), has emerged as a significant environmental contaminant due to its widespread occurrence and associated ecological risks. Conventional wastewater treatment plant (WWTP) processes are often ineffective in completely removing TCS, emphasizing the need for more efficient and cost-effective treatment approaches. In the present study, bacterial isolates obtained from wastewater were evaluated for their ability to remove TCS at a concentration of 2 mg L-1 using free cells, microbial consortia, and immobilized systems. Three bacterial strains, namely Bacillus pumilus, Bacillus licheniformis, and Pseudomonas stutzeri, along with a consortium consisting of B. pumilus and B. licheniformis, were investigated for their TCS removal efficiency. Among the tested isolates, B. pumilus exhibited rapid removal of TCS, achieving approximately 90 % removal within 3 h. The microbial consortia showed enhanced performance compared to individual strains, reducing TCS concentrations to below the analytical detection limit. Furthermore, immobilized bacterial systems significantly improved the removal efficiency, indicating greater stability and sustained metabolic activity compared to free cells. Overall, the findings suggest that wastewater derived bacteria, particularly when employed as consortia and immobilized systems, represent a promising approach for the treatment of TCS contaminated wastewater.