No abstract

Naproxen, a non‐steroidal anti‐inflammatory drug, commonly used for fever, inflammation and for different health problems, as found for many pharmaceuticals has been recently detected in sewage effluents, surface, and ground water, and sometimes even in drinking water. An advanced wastewater treatment plant (WWTP), utilizing ultra‐filtration, activated charcoal (AC), and reverse osmosis (RO) after the primary biological treatment, showed that both nano‐ and micro‐ultrafiltration were not sufficient for removing spiked naproxen to a safe level, whereas RO membrane was quite efficient. No naproxen degradation was detected in pure water whereas it underwent biodegradation within three days in activated sludge giving O‐desmethyl‐naproxen. Adsorption performed on micelle–clay complex and AC under steady state conditions, showed that the former adsorbent is highly effective in removing naproxen with fast kinetics. Laboratory micelle–clay complex filters under continuous naproxen‐spiked water flowing were found to be efficient in removing this drug, suggesting that the efficiency of existing advanced WWTP could be improved by including filtration columns filled with suitable sand/micelle–clay mixtures.

Removal of Cr(VI) from aqueous solutions under different conditions was investigated using either clay (montmorillonite) or micelle-clay complex, the last obtained by adsorbing critical micelle concentration of octadecyltrimethylammonium ions onto montmorillonite. Batch experiments showed the effects of contact time, adsorbent dosage, and pH on the removal efficiency of Cr(VI) from aqueous solutions. Langmuir adsorption isotherm fitted the experimental data giving significant results. Filtration experiments using columns filled with micelle-clay complex mixed with sand were performed to assess Cr(VI) removal efficiency under continuous flow at different pH values. The micelle-clay complex used in this study was capable of removing Cr(VI) from aqueous solutions without any prior acidification of the sample. Results demonstrated that the removal effectiveness reached nearly 100% when using optimal conditions for both batch and continuous flow techniques.