The consumption of pharmaceuticals has rapidly increased on a global scale due to the serious increase in Covid-19, influenza and respiratuar sinsityal virus, which is called “triple epidemic” in the world. The use of non-prescription analgesic and anti-inflammatory drugs (AAIDs), especially paracetamol, is higher compared to pre-pandemic. This increased the AAIDs load discharged to the aqueous media through sewerage treatment plant (STP). Therefore, simple and effective treatment options for removing AAIDs from STP effluents are needed. The aim of the study was to remove AAIDs (paracetamol, acetylsalicylic acid, codeine, diclofenac, ibuprofen, indomethacin, ketoprofen, mefenamic acid, naproxen, and phenylbutazone) from STP effluents by nearly pure natural clay Na-montmorillonite. The Na-montmorillonite taken from the Ordu region in the northern part of Turkey. Surface area of the Na-montmorillonite is 99.58 m²/g and CEC is 92.40 meq/100 g. The removal efficiencies of AAIDs using Na-montmorillonite were between 82 ± 5% (ibuprofen) and 94 ± 4% (naproxen). Paracetamol was used as a model compound in kinetic and isotherm model studies. Freundlich isotherm model and the pseudo second order kinetic model were the best-fit using the obtained experimental data. Film diffusion governed its rate mechanism. The paracetamol adsorption capacity was acquired as 244 mg/g at 120 min contact time at pH 6.5 at 25 °C. With this study, it could be shown that montmorillonite can be used effectively to eliminate paracetamol from STP effluent. Natural clay can be used as a simple, inexpensive and effective adsorbent for removing AAIDs from STP effluents.

In this study, the occurrences, temporal concentration variations and ecotoxicological risks were determined for 18 polycyclic aromatic hydrocarbons (PAHs); 7 congeners of polychlorinated biphenyls (PCBs), and 18 selected organochlorine pesticides (OCPs) in the anaerobically digested sewage sludge samples obtained from a conventional wastewater treatment plant (WWTP) in Konya, Turkey. Flowrate of the evaluated WWTP was 200,000 m³/day, with the production of 140 tons/day treated sewage sludge. Total 18 PAHs were in the range of 1,203 – 17,599 μg/kg of dry matter (dm); total PCBs were in the range of 51.26 – 561.37 μg/kg dm, and total OCPs were in the range of 4.90 – 13.11 μg/kg dm. The highest concentrations were determined for fluoranthene among PAHs, with 2445 μg/kg dm, PCB118 congener with 514 μg/kg dm, and δ-HCH among OCPs with 2.44 μg/kg dm. Considering the average daily production amounts of treated sludge, the highest mass loads were 1,785 g/day for total PAHs; 79 g/day for total PCBs; and 1 – 2 g/day for total OCPs, while the annual mass load was estimated to be approximately 7.3 kg. An ecotoxicological risk assessment was performed by estimation of risk quotients (RQs). High risk for soil ecosystem was identified due to PAHs and PCBs ingredient of sludge, while lower risk was determined for OCPs compounds. The highest RQ values were determined for pyrene (RQ: 1337) among PAHs, PCB118 congener (RQ: 7608), and γ-HCH (RQ: 5.23) among OCPs. Findings of this study show that sewage sludge can be an important source in the spread of persistent pollutants to the environment, and may pose a risk for soil ecosystem.