Fate of selected pharmaceuticals in hospital and municipal wastewater effluent: occurrence, removal, and environmental risk assessment

The concentrations and distribution of beta-blockers, lipid regulators, and psychiatric and cancer drugs in the influent and effluent of the municipal wastewater treatment plant (WWTP) and the effluent of 16 hospitals that discharge into the wastewater treatment plant mentioned in this study at two sampling dates in summer and winter were examined. The pharmaceutical contribution of hospitals to municipal wastewater was determined. The removal of target pharmaceuticals was evaluated in a WWTP consisting of conventional biological treatment using activated sludge. Additionally, the potential environmental risk for the aquatic receiving environments (salt lake) was assessed. Beta-blockers and psychiatric drugs were detected in high concentrations in the wastewater samples. Atenolol (919 ng/L) from beta-blockers and carbamazepine (7008 ng/L) from psychiatric pharmaceuticals were detected at the highest concentrations in hospital wastewater. The total pharmaceutical concentration determined at the WWTP influent and effluent was between 335 and 737 ng/L in summer and between 174 and 226 ng/L in winter. The concentrations detected in hospital effluents are higher than the concentrations detected in WWTP. The total pharmaceutical contributions from hospitals to the WWTP in summer and winter were determined to be 2% and 4%, respectively. Total pharmaceutical removal in the WWTP ranged from 23 to 54%. According to the risk ratios, atenolol could pose a high risk (risk quotient > 10) for fish in summer and winter. There are different reasons for the increase in pharmaceutical consumption in recent years. One of these reasons is the COVID-19 pandemic, which has been going on for 2 years. In particular, hospitals were operated at full capacity during the pandemic, and the occurrence and concentration of pharmaceuticals used for the therapy of COVID-19 patients has increased in hospital effluent. Pandemic conditions have increased the tendency of people to use psychiatric drugs. It is thought that beta-blocker consumption has increased due to cardiovascular diseases caused by COVID-19. Therefore, the environmental risk of pharmaceuticals for aquatic organisms in hospital effluent should be monitored and evaluated.

Automated summary

This study examined the concentrations and distribution of pharmaceuticals in the influent and effluent of a municipal wastewater treatment plant and hospital effluents. It found that beta-blockers and psychiatric drugs were detected in high concentrations in the wastewater samples, with hospitals contributing 2-4% of total pharmaceuticals in the plant. The removal of pharmaceuticals in the treatment plant ranged from 23% to 54%.