Table 1.

Behaviour, fate processes and removal efficiencies for selected COVID-19 therapeutic drugs in aquatic environments

Compound	Aquatic matrix type	Contaminant levels	Fate process or treatment method	Outcome or removal efficiency	Half-life	References
Azithromycin	Municipal wastewater treatment plant	0.12–3.68 µg/L	Activated sludge system with nitrification	No removal (0%) was observed	NR	Bhandari et al. (2008)
Azithromycin	Simulated municipal wastewater effluent	Simulated	Photocatalysis using nanostructured TiO2	Successfully removed within 30 min	NR	Čizmić et al. (2019)
Azithromycin	Artificial freshwater	Simulated	Solar-like light	Removal was slow	20 h	Tong et al. (2011)
Azithromycin	Simulated California river system	Simulated	Aerobic and anaerobic degradation	Very slow degradation rate under aerobic conditions No degradation under anaerobic conditions	82.52 days (under aerobic conditions)	Vermillion Maier and Tjeerdema (2018)
Chloroquine	Simulated membrane reactor	10 g/L	Melanin-covered E. coli sorption process	98.2% removal was achieved	NR	Lindroos et al. (2019)
Chloroquine	Wastewater treatment plant (WWTPs)	NR	Primary biodegradation took weeks to months	63% removal from WWTPs	NR	Kuroda et al. (2021)
Hydroxychloroquine	Wastewater treatment plant (WWTPs)	NR	Primary biodegradation took weeks to months	6.0% removal from WWTPs	NR	Kuroda et al. (2021)
Hydroxychloroquine	Ultrapure, spring, river, and sea water	Simulated	Photolysis under solar radiation (300–800 nm)	– pH affects degradation process – Humic acids, nitrate, and Fe (III) enhanced photodegradation	11.6 h (ultrapure water) 0.42 h (river water)	Dabić et al. (2019)
Dexamethasone	Batch laboratory system	5–40 mg/L	Batch adsorption using clinoptilolite zeolite	Maximum of 78% was removed	NR	Mohseni et al. (2016)
Indomethacin	Batch laboratory system	Simulated	Ozonation	80% removal rate was achieved	NR	Zhao et al. (2017)
Indomethacin	Batch laboratory system	Simulated	Thermo-activated persulphate oxidation	85.5% removal rate was achieved	NR	Li et al. (2018)
Ivermectin	Batch laboratory system using real field samples	Simulated	Natural attenuation in a water/sediment system	31.3% of initially applied ivermectin were transformed	< 6 h	Prasse et al. (2009)
Ivermectin	Simulated water/soil system using field soil samples	500 µg/L	Dissipation under aerobic condition at 19.3 °C	NR	15.5 days (sandy soil) 11.5 days (clay soil)	Rath et al. (2016)
Ivermectin	Simulated water/soil system using field soil samples	500 µg/L	Photocatalysis under UV-C and TiO2	98% removed	NR	Rath et al. (2016)
Ivermectin	Outdoor aquatic mesocosm	0–1000 ng/L	Concentration in sediment increased and became stable	NR	3–5 days (in water)	Sanderson et al. (2007)
Ivermectin	Field water and sediment samples	Simulated using 14C-labelled compounds	Dissipation in water/sediment system	NR	15 days (in sediment) 2.9 days (in water)	Löffler et al. (2005)
Metformin	Wastewater treatment plant	Up to 100 µg/L	– Activated carbon and flocculation were least effective – Ordered chlorination and ozonation were most effective	88–97% removed	NR	Scheurer et al. (2012)
Oseltamivir	River water	50 µg/L	Daylight exposure	NR	17.8 days	Bartels and von Tümpling (2008)
Oseltamivir	Sewage works Surface waters Water/sediment system	NA	NR	– No removal from sewage works – No degradation in surface waters – 50% degradation in water/sediment system	100 days in water/sediment system	Straub (2009)
Oseltamivir	Synthetic influent wastewater	NA	Simulated activated sludge system	41% removed	NR	Slater et al. (2011)
Ribavirin	Ribavirin medicine wastewater	Chemical oxygen demand (COD) of 7000 mg/L	Universal broadcast filter anaerobic reactor system	72.8% COD removed	NR	Jain et al. (2013)
Spironolactone	Wastewater	1 mg/L	Activated sludge system	> 90% removed	NR	Sulaiman et al. (2015)

NR not reported, NA not applicable