Removal of Diclofenac from Water using an Hybrid Process Combining Activated Carbon Adsorption and Ultrafiltration or Microfiltration

Abstract

Small amounts of pharmaceuticals are increasingly found in natural waters and wastewaters in treatment plants. Several processes are developed for their removal such as hybrid membrane processes. These techniques integrate membrane filtration (mainly ultrafiltration or microfiltration) to a physical technique (such as flocculation or sorption on activated carbon). In this study, we report results on a process with sorption on activated carbon and microfiltration or ultrafiltration using a ceramic membrane, with a specific attention to the influence of the membrane pore size. The membranes showed little fouling at the experimental conditions used (maximum 500 mg/L activated carbon), while an important increase in conductivity was observed in permeate samples due to the salting out of ions from the activated carbon particles. Besides, the removal of diclofenac and humic acid (both at 10 mg/L) was higher than 90 % during the treatment with both ultrafiltration and microfiltration, however microfiltration was preferred due to its higher flux. These results suggest that hybrid processes of activated carbon/ultrafiltration or microfiltration could be interesting alternatives for processing waters containing small amounts of pharmaceuticals.