İkincil arıtma atıksuyunda kalan farmasötiklerin granüler aktif karbon adsorpsiyonuyla giderimi

This study investigates the removal of four pharmaceuticals: acetaminophen (ACT), carbamazepine (CBZ), erythromycin (ERY) and sulfamethoxazole (SMX) by granular activated carbon (GAC). Firstly, sorption and biodegradation potential of these pharmaceuticals was studied and removal mechanisms (primary, secondary, cometabolic substrate, etc.) were investigated. After that, adsorption experiments were carried out in batch reactors to obtain isotherm constants. Then, the removal of pharmaceuticals was examined in rapid small-scale continuous-flow GAC columns. The results were compared with outputs of a model called AdDesign. Results showed that sorption of these pharmaceuticals was very low and they were biodegraded by activated sludge to some extent. ACT was highly biodegradable, whereas CBZ was the least biodegraded pharmaceutical. Adsorption experiments showed that the affinity of pharmaceuticals to adsorb onto GAC was higher when they were the only pharmaceutical, but when they were in the mixture the affinities were lower that indicated there was a competition between them. On the other hand, adsorption of the bulk organics present in secondary effluent on GAC was very low. Small column tests showed that there was no full breakthrough of either of the pharmaceuticals in the experimental period because of the low initial concentrations. In the presence of background organic matter, higher concentrations of pharmaceuticals were observed in the effluent which indicated a competition between the pharmaceuticals and the background organic matter. Through the use of the AdDesign model the column performance could be studied in a longer term and the full breakthrough of pharmaceuticals could be demonstrated under various conditions.