A decadal analysis to unravel the global status of emerging contaminants in wastewaters and comparison with the Indian context

Abstract

The prevalence of emerging contaminants (ECs) in wastewaters is troublesome because of their widespread and persistent nature, posing a threat to living organisms when exposed for prolonged durations. We conducted an extensive literature assessment for this study to present the overall global status of the occurrence of ECs regardless of their class by compiling relevant publications from the previous decade. The most commonly investigated category were pharmaceuticals (particularly antibiotics and anti-inflammatories/analgesics), personal care products (PCPs), and industrial chemicals (IDC). The most concentrated compounds in the global influents and effluents were Acetaminophen (500 μg/L), an analgesic, and Saccharine (379 μg/L), an artificial sweetener, reported from Canada and India, respectively. Irrespective of its prevalence, the presence of artificial sweeteners (ASWs), surfactants, etc., in wastewaters have often been overlooked. Most of the sub-classes exhibited minor to moderate elimination efficiency, with anti-diabetic drugs showing the highest among all. However, insignificant changes (artificial sweeteners, phthalates, etc.) and negative removal (anti-depressants, anti-psychotics, etc.) were also observed. Furthermore, Caffeine, Ampicillin, and Trimethoprim were reported at extremely high concentrations in India than in the rest of the world. Irgasan, Benzothiazoles, Sparfloxacin, etc., were also quite predominant in India, which has yet to be recorded in any other country. Therefore, the universally implemented conventional approaches are incapable of total elimination for all ECs. Hence, the traditional methods should be paired with the advanced techniques that have shown positive removal for certain ECs, which can be a promising solution to this problem. These findings will aid in establishing which classes and compounds demand immediate attention for further investigation and monitoring, allowing water managers to take necessary measures to reduce pollutant levels at the source and develop water protection policies.