Abstract

Pharmaceutical residues in the environment have become known as “emerging contaminants” because of their increasing frequency of detection in the aquatic and terrestrial systems. Both human and veterinary pharmaceuticals are introduced into the environment via many different routes, including discharges from municipal wastewater treatment plants (WWTPs), and via land application of animal manure and biosolids to fertilize croplands. Most conventional WWTPs cannot fully remove pharmaceuticals; thus, advanced water treatment systems are being explored to eliminate or minimize pharmaceuticals in WWTP effluents because of the potential ecological effects they may cause. While the concentrations of pharmaceuticals in drinking water sources are relatively low to be of concern to human health, the efficiency of different advanced oxidation techniques to remove recalcitrant pharmaceuticals in drinking water is being evaluated.The importance of identifying and assessing the toxicity of transformation products (biotic and abiotic) of pharmaceuticals in engineered treatment systems and under natural environments should not be ignored.Recent studies have demonstrated that transformation products of organic contaminants may sometimes exhibit residual toxicity or biological activity, or in few cases, may even be more potent than the parent compound itself.