REMOVAL OF ANTI-INFLAMMATORY DRUGS AND ENDOCRINE DISRUPTING COMPOUNDS BY GRANULAR ACTIVATED CARBON

Endocrine disrupting chemicals (EDCs) are compounds of anthropogenic mainly origin that interfere with the endocrine system of animals and humans thus causing a series of disorders. EDCs is a very heterogeneous group of compounds (e.g. PCBs, PBBs, plasticizers, pesticides, pharmaceuticals, etc.). Pharmaceuticals and Personal Care Products (PPCPs) is a rather heterogeneous group of chemicals consisting of antibiotics, analgesics, anti-inflammatory drugs, beta-blockers, diuretics, blood lipid regulators, anti-diabetes, hormones, psychiatric, betaagonists, antiseptics, cosmetics etc. Among these compounds anti-inflammatory drugs ibuprofen (IBF), naproxen (NPX), diclofenac (DCF) and ketoprofen (KFN) and EDCs nonylphenol (NPs), bisphenol A (BPA) and triclosan (TCS) are of significant interest due to their persistent detection in raw and treated water and wastewater. Activated carbon is a well-known process very often used in Water Treatment Plants (VVTPs) for removing various organic contaminants from water. Activated carbon is applied in two forms; in a powdered form (PAC) or in a granular form (GAC) in packed bed filters. Breakthrough curves provide useful information for the design of a GAC system. In the literature there are few data regarding the removal of anti-inflammatory drugs and EDCs from water through GAC whereas breakthrough curves for such compounds are limited. In view of the above the objective of this study was to evaluate the efficiency of adsorption at Granular Activated Carbon (GAC) columns in the removal of the aforementioned compounds from water at concentrations found in the aquatic environment (ng/L) and to obtain breakthrough curves for each chemical. For this scope several fixed bed column experiments have been conducted in a pilot-scale GAC column system. All experiments were performed with tap water spiked with the target compounds at concentrations up to 1 or 2 mu g/L. The untreated water was added to the GAC column system through a peristaltic pump. For the determination of the target compounds a chromatographic method developed by Samaras, et al., (2011) was used. The experimental results showed that adsorption on GAC column could effectively remove all of the ECs examined. In general terms EDCs were more effectively removed from the water than the PPCPs. Among all target compounds TCS exhibited the higher removal efficiency. For the evaluation of the breakthrough curve of each EC the Bohart-Adams model was used and the adsorptive capacity (N-0) and adsorption rate constant (K) was calculated for each target compound. According to the Bohart-Adams model the constants N-0 and K are functions of the linear flow rate of the adsorbate. However, the expected correlation was not recorded in the present study, most probably due to the microbiological activity observed in the GAC columns.