Removal of antimicrobial resistance from secondary treated wastewater – A review

Antimicrobial resistance (AMR) is one of today's most important concerns. Indiscriminate use of antibiotics and their release into the water bodies have been known to afflict the bacterial population of the ecosystem and cause the development of antibiotic resistance bacteria (ARB) and antibiotic resistance genes (ARGs). Wastewater is a cocktail of different pollutants, including antibiotics. These pollutants, along with antibiotics, impose selection pressure on AMR development. Wastewater treatment plants (WWTPs) receiving such pollutants through the inlet could redress only a fraction of AMR removal from the effluent. The treated effluent from a WWTP directly afflicts the population of any region. Therefore it is essential to focus on the problems associated with the AMR present in the treated effluent and their possible mitigation strategies. This review focuses on the approaches studied and applied in AMR removal and their associated shortcomings. This review also talks about various bench-scale studies based on nanomaterials and their potential to exhibit remarkable adsorption capacity owing to their surface area; however, despite their performance, they are an unattractive option. Lastly, the review observes that since ARGs are nucleic acids, various medical research wherein nucleic acid (NA) adsorption is common could be utilized and studied for ARGs removal. Particular emphasis has been laid on the fact that adsorption is a highly pH-dependent process and that manipulating the operating pH in a wastewater treatment industry is undesirable. Therefore, selecting adsorbent materials that could exhibit appreciable adsorption capacity for ARGs in the working pH of secondary effluent is a crucial factor to consider.