Membrane filtration of two sulphonamides in tertiary effluents and subsequent adsorption on activated carbon

The adsorption behaviour of two polar organic micropollutants (N-n-butylben zenesulphonamide and sulphmethoxazole) onto powdered activated carbon (PAC) under competitive conditions prior to and after filtration with a tight ul trafiltration membrane wits examined. The sulphonamides were spiked into mi crofiltered tertiary municipal effluent in mug L-1 quantities. Ultrafiltrat ion of these effluents resulted in better adsorbability for both the microp ollutants and the background organic matter in the permeates compared to th e feed waters. This behaviour seems to be caused by a reduced blocking of m icropores by lower concentrations of high molecular weight compounds in mem brane filtrates. A combined treatment of ultrafiltration prior to adsorptio n can therefore reduce the carbon demand for potentially harmful micropollu tants in effluents. (C) 2001 Elsevier Science Ltd. All rights reserved.