Removal of Pesticides from Water Using Granular Activated Carbon and Ultrafiltration Membrane—A Pilot Plant Study

The use of powdered activated carbon for fouling control in the membrane processes is limited by some secondary problems associated with its use, like cake formation, long backwash times and blackening of pipes. Granular activated carbon (GAC) was used as an alternative of powdered activated carbon due to its large particle size which was kept from being entering into the membrane system. The secondary problems associated with the use of powdered activated carbon as foul control were not observed for granular activated carbon. Langmuir and Freundlich adsorption were used to describe the adsorption of 2,4-D and paraquat on GAC. Adsorption capacity of adsorbent was high for 2,4-D as compared to paraquat. Also, the R value was high for Langmuir model as compared to Freundlich model. Retention percentage of 2,4-D by membrane was high and thus the decline in permeate flux was high as compared to paraquat in ultrafiltration (UF) membrane process. 100% retention of 2,4-D was achieved in GAC/UF hybrid system. Improved permeate fluxes were observed for both contaminants in the hybrid system.