Natural deep eutectic solvents for turbidity removal from synthetic pharmaceutical wastewater/Prirodni duboki eutekticki rastvaraci za uklanjanje zamucenosti iz sinteticke farmaceutske otpadne vode

Contamination of water resources by active pharmaceutical ingredient wastes is among major environmental concerns. To prevent major disruptions of aquatic life, an efficient and environmentally-friendly turbidity removal procedure of common contaminants such as paracetamol should be established. In this study, several natural deep eutectic solvents (NADESs) were screened to reduce the turbidity of simulated water contaminated with paracetamol below the standard turbidity limit recommended by the National Water Quality Standards for Malaysia (50 NTU). The optimal operating parameters (NADES dosage, stirring time and operating pH) were determined. Under optimized conditions, stearic acid-based NADES achieved the highest turbidity removal of 97.5%. High coagulation performances were investigated based on molecular interaction using COSMO-RS (COnductor like Screening MOdel for Real Solvents) [sigma]-profile and [sigma]-potential (histogram of charge density distribution over molecular surface) and showed high affinity between the NADES compounds and paracetamol. Thus, NADESs are promising candidates for turbidity removal of paracetamol from water and are viable in further investigations for effluent treatment applications. Keywords: Active pharmaceutical ingredients; flocculation; coagulation; wastewater treatment. Kontaminacija vodnih resursa otpadom aktivnih farmaceutskih sastojaka je medu glavnim problemima zivotne sredine. Da bi se sprecili veliki poremecaji u prirodnim vodama, treba uspostaviti efikasan i ekoloski prihvatljiv postupak uklanjanja zamucenja od strane uobicajenih zagadujucih materija, kao sto je paracetamol. U ovoj studiji je istrazivana upotreba nekoliko prirodnih dubokih eutektickih rastvaraca u cilju smanjivanja zamucenosti simulirane vode kontaminirane paracetamolom ispod standardne granice zamucenosti koju preporucuju Nacionalni standardi kvaliteta vode u Maleziji (50 NTU). Odredeni su optimalni radni parametri (kolicina eutektickih rastvaraca, vreme mesanja i radna pH vrednost). Pod optimizovanim uslovima, koriscenje eutektickog rastvaraca na bazi stearinske kiseline dovelo je do najveceg smanjenja zamucenosti od 97,5%. Visoke performanse koagulacije su ispitivane na osnovu molekularne interakcije, koriscenjem COSMO-RS (CONductor like Screening MOdel for Real Solvents) [sigma]-profila i [sigma]-potencijala (histogram raspodele gustine naelektrisanja preko molekularne povrsine) i pokazali su visok afinitet izmedu eutektickih rastvaraca