Nihan Özengin

Active substances of drugs can cause various adverse effects by accumulating in the ecosystem. Many medications are resistant to biodegradation, given the recipient media in conventional wastewater treatment plants, and are thus released into the environment after only partial purification or no purification at all. The study focuses on 13 different pharmaceutical compounds belonging to drug classes of anti-depressants, antiepileptic’s, anti-inflammatories, beta-blockers, lidocaine, and stimulants. These compounds were selected with reference to the literature as the ones most commonly encountered in domestic wastewater, surface, and groundwater. The presence of these compounds in the wastewater samples from Sakarya sewage and wastewater treatment plant was investigated. For this purpose, composite samples were taken at various sampling points, and duly analyzed. The analysis revealed the presence of the pharmaceutical residues in the sewage waters from Sakarya Municipality. Some of them were still present in the effluent of the treatment plant. On the other hand, fluoxetine, propranolol, and metoprolol drug active ingredients were not detected at any sampling point. Among all the compounds examined, the highest percentage of residues were observed in the case of active caffeine and paracetamol. In the light of these findings, advanced treatment units such as high-pressure membrane systems (including ozonizing, ultrafiltration, and reverse osmosis) can help adsorption rates at the treatment plant, increasing removal efficiency regarding drug compounds.

The aim of this research was to expose individual removals of copper, chromium, nickel, and lead from aqueous solutions via biosorption using nonliving algae species, Chara sp. and Cladophora sp. Optimum pH values for biosorption of copper (II), chromium (III), nickel (II), and lead (II) from aqueous solutions were determined to be 6, 7, 7, and 3 for Cladophora sp. and 5, 3, 5, and 4 for Chara sp. respectively. Maximum adsorption capacities of Chara sp. [10.54 for chromium (III) and 61.72 for lead (II)] and Cladophora sp. [6.59 for chromium (III) and 16.75 and 23.25 for lead (II)] for chromium (III) and lead (II) are similar. On the other hand, copper (II) and nickel (II) biosorption capacity of Cladophora sp. [14.28 for copper (II) and 16.75 for nickel (II)] is greater than Chara sp. [6.506 for copper (II) and 11.76 for nickel (II)]. Significantly high correlation coefficients indicated for the Langmuir adsorption isotherm models can be used to describe the equilibrium behavior of copper, chromium, nickel, and lead adsorption onto Cladophora sp. and Chara sp.