Contents lists available at ScienceDirect Environmental Research journal homepage: www.elsevier.com/locate/envres Review article Pharmaceutically active compounds in aqueous environment: A status, toxicity and insights of remediation Abhradeep Majumder a , Bramha Gupta b , Ashok Kumar Gupta c,∗ a School of Environmental Science and Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India b School of Water Resources, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India c Environmental Engineering Division, Department of Civil Engineering, Indian Institute of Technology Kharagpur, Kharagpur, 721302, India ARTICLEINFO Keywords: Ecotoxicological impacts Drinking water equivalent limit Degradation efciency AOPs Pharmaceuticals ABSTRACT Pharmaceutically active compounds (PhACs) have pernicious efects on all kinds of life forms because of their toxicological efects and are found profoundly in various wastewater treatment plant infuents, hospital ef- fuents, and surface waters. The concentrations of diferent pharmaceuticals were found in alarmingly high concentrations in various parts of the globe, and it was also observed that the concentration of PhACs present in the water could be eventually related to the socio-economic conditions and climate of the region. Drinking water equivalent limit for each PhAC has been calculated and compared with the occurrence data from various con- tinents. Since these compounds are recalcitrant towards conventional treatment methods, while advanced oxi- dation processes (AOPs) have shown better efciency in degrading these PhACs. The performance of the AOPs have been evaluated based on percentage removal, time, and electrical energy consumed to degrade diferent classes of PhACs. Ozone based AOPs were found to be favorable because of their low treatment time, low cost, and high efciency. However, complete degradation cannot be achieved by these processes, and various transformation products are formed, which may be more toxic than the parent compounds. The various trans- formation products formed from various PhACs during treatment have been highlighted. Signifcant stress has been given on the role of various process parameters, water matrix, oxidizing radicals, and the mechanism of degradation. Presence of organic compounds, nitrate, and phosphate usually hinders the degradation process, while chlorine and sulfate showed a positive efect. The role of individual oxidizing radicals, interfering ions, and pH demonstrated dissimilar efects on diferent groups of PhACs. 1. Introduction The presence of pharmaceutically active compounds (PhACs) in the aqueous ecosystem have been known from the mid-20th century. However, in the last few years, with the advent of new analytical technologies and after meticulous studies about the ecological impacts of PhACs, their presence has become an emerging concern. Presence of PhACs in the aquatic ecosystem pose a serious threat to both aquatic and terrestrial organisms. Although these compounds are present in vestigial levels, prolonged exposure can have a pernicious efect on human health, aquatic life, and plants, etc. Unrestrained use of PhACs such as antibiotics, analgesics, β-blockers, hormones, stimulants, anti- epileptics, etc. over the past few decades has polluted many aquatic ecosystems. At present, approximately 3000 compounds are used as medicines with annual production exceeding hundreds of tons (Sim et al., 2011). The worldwide pharmaceutical revenue has increased from 390.2 bil- lion US$ in 2001 to 1105.2 billion US$ in 2016, indicating an increase in pharmaceutical consumption by 2.8 times over the last 15 years (Statista, 2018). The PhACs present in the aquatic ecosystem originates from sources like domestic sewage, hospital efuent, pharmaceutical manufacturing industries, animal husbandries, etc. https://doi.org/10.1016/j.envres.2019.108542 Received 29 January 2019; Received in revised form 12 June 2019; Accepted 17 June 2019 Abbreviations: ADI, Acceptable daily intake; AO, Anodic Oxidation; AOP, Advanced oxidation process; BDD, Boron-doped diamond; DWEL, Drinking water equivalent limit; DWI, Daily water intake; e−, Electrons; eV, Electron volt; EEO, Electrical energy per order; EF, Electro Fenton; GAC, Granular activated carbon; h + , Holes; H 2 O 2 , Hydrogen peroxide; HOCl, Hypochlorous radicals; kGy, Kilo Grays; kHz, Kilohertz; Kow, Octanol-water partition coefcient; kW, Kilowatt; mA, Milli Ampere; meV, Milli electron volt; OH, Hydroxyl radical; O 2 , Superoxide radical; PEF, Photo-electro Fenton; PhACs, Pharmaceutically active compound; pKa, Acid dissociation constant; PNEC, Predicted no efect concentration; PMS, Peroxymonosulphate; PS, Persulphate; PZC, Point of zero charge; SHE, Standard hydrogen electrode; SO 4 2- , Sulfate radicals; W, Watt; WWTP, Wastewater treatment plant ∗ Corresponding author. E-mail addresses: abhradeep.majumder@iitkgp.ac.in (A. Majumder), guptabramha@iitkgp.ac.in (B. Gupta), akgupta@iitkgp.ac.in (A.K. Gupta). Environmental Research 176 (2019) 108542 Available online 21 June 2019 0013-9351/ © 2019 Elsevier Inc. All rights reserved. T