Mass loading and removal of pharmaceuticals and personal care products, including psychoactive and illicit drugs and artificial sweeteners, in five sewage treatment plants in India

Abstract

Despite the high consumption of pharmaceuticals, mass loading and removal of these compounds in sewage treatment plants (STPs) in India have not been investigated. In this study, 43 pharmaceuticals and personal care products as well as 13 of their metabolites were analyzed in five domestic STPs (wastewater influent, effluent, and sludge) and in raw domestic sewage collected in open sewerage channels in residential areas in India. The mean concentrations of amphetamine in two of the five STPs (mean: 4300ng/L and 4720ng/L) were the highest ever reported for wastewater influents, globally. Among artificial sweeteners, saccharin was the most abundant compound in influents (mean: 303,000ng/L, df: 100%), followed by cyclamate [3460ng/L, detection frequency (df): 75%] and sucralose (1460ng/L, df: 100%). Elevated mean concentrations of an antimicrobial (triclocarban=6180ng/L), analgesic (ibuprofen=2320ng/L), antihypertensive (atenolol=3180ng/L), illicit drug (amphetamine=984ng/L), and saccharin (419,000ng/L) were found in the Cooum River in Chennai. The median removal efficiencies of pharmaceuticals and personal care products (PPCPs) ranged from 5% (norcocaine) to 100% (triclosan) for the five STPs. On the basis of the concentrations measured in influents, the mass loadings of PPCPs were estimated to range from 0.1 (norquetiapine) to 77,800 (saccharin) mg/d/1000 people. An estimated 2.55kg of triclocarban, 3.24kg of carbamazepine, 6.93kg of amphetamine, and 252kg of saccharin were discharged from a typical STP with an average flow rate of 20.7 million liters per day (serving a population of 325,000) in India.