An innovative sustainable means for removing pathogens from tertiary treatment wastewater discharges in western and emerging economies

Conventional methods of wastewater treatment which typically include biological degradation and membrane filtration are only partially effective with regards to the removal of antibiotics and human pathogens. Interestingly, there are no set discharge limits for these dangerous constituents and their release into the natural aquatic environment is exacerbating the proliferation of antimicrobial parasites. Although chlorination and ozonation enhances the disinfection process, their usage can generate toxic by-products or more harmful antimicrobial entities, thus contributing to the AMR propagation.
Adsorption is a versatile wastewater treatment alternative to the conventional technologies, which offers high efficiency of contaminant removal, while encompassing simplicity of application and operation. Moreover, it can address very low residual concentrations of antibiotics in discharges. In Western and developing economies alike, the AMR threat can be controlled using activated carbon (ac) as an effective but costly adsorbent for antibiotics present in wastewaters. However, this material is associated with high manufacturing and reactivation costs and has a significant carbon footprint.
The ongoing research at Ulster University proposes a sustainable and cost-effective solution. The method entails the treatment of timber waste, i.e., sawdust, using a range of inorganic acids and alkalis, to isolate modified ligno-cellulosic substrates for pollutant containment. Initial studies with vancomycin aqueous solutions found that this treatment of sawdust enhanced its capacity 5-fold, reaching a maximum removal level of 63%. While this initial figure is lesser than the benchmark removal using ac (98%), the environmental and cost benefits of sawdust are significantly higher than for activated carbon.