Comparison of the Efficiency of Adsorption, Ozonation, and Ozone/Activated Carbon Coupling for the Removal of Pharmaceuticals from Water

Abstract

The treatment by adsorption on activated carbon, ozonation, and ozone/activated carbon coupling of a solution containing six pharmaceutical compounds (metoprolol, carbamazepine, terbutaline, fluoxetine, and sulfamethoxazole) chosen among different pharmaceutical classes has been investigated. The efficiency of the processes was estimated through the removal of each target pollutant and the evolution of both toxicity (inhibition of Vibrio fisheri bioluminescence) and the total organic carbon concentration. The influence of pH, ranging from 3 to 7, on the process efficiency was also studied. In each experimental condition, the fastest removal of the pharmaceutical compounds was achieved with ozone/activated carbon coupling. Nevertheless, this process (ozonation and ozone/activated carbon coupling) leads to the formation of toxic by-products that significantly increase the toxicity of the treated effluent. Their removal would require extending the treatment time or increasing the ozone concentration, which increases the treatment costs. Based on the experimental results in these experimental conditions and the toxicity evolution in the liquid phase, the adsorption on activated carbon seems to be the most efficient and the safest process to remove pharmaceutical compounds from water.