Removal of Two NSAIDs: Naproxen and Diclofenac and a Heavy Metal Cr (VI) by Advanced Membranes Technology.

ODTMA-micelle-clay complex as an efficient adsorbent was prepared from a cationic surfactant, octadecyltrimethylammonium (ODTMA) and a negatively charged clay (montmorillonite). It is characterized with a positive charge and large hydrophobic sites. The micelle- clay complex was investigated towards removal of the ant-inflammatory drugs (NSAIDs), Diclofenac and Naproxen and a heavy metal Cr (VI) as part of comprehensive evaluation study to utilize this adsorbent in advanced wastewater treatment technology. Stability studies demonstrated that while Diclofenac potassium was completely stable in fresh water and in sludge Naproxen underwent biodegradation in sludge to provide O-desmethyl naproxen (DMN) as its single metabolite. Al-Quds Wastewater Treatment Plant (WWTP) which includes ultrafiltration (UF) (hollow fiber HF and spiral wound SW) membranes, activated carbon (AC) and reverse osmosis (RO) has demonstrated high removal efficiency toward these two NSAIDs and Naproxen metabolite (DMN). Furthermore, the filtration results by Al-Quds WWTP revealed that the UF-HF membrane was not efficient in removing the three studied pollutants from wastewater. In contrast, the RO and AC membranes were found to be quite efficient in removing (100%) all studied pharmaceuticals. The column filtration experiments with a mixture of sand and ODTMA-micelle-clay complex as adsorbent indicated 100% removal of the adsorbates, Diclofenac and Naproxen and Naproxen metabolite (SMN). Similarly, ODTMA-micelle-clay complex was found to completely remove the heavy metal Cr (VI) from its aqueous solutions at ambient pH and temperature.