Novel application of local GAC adsorption to remove organic matters and pesticides in rural drinking water treatment

Novel application of granular activated carbon (GAC) using renewable and low cost materials to remove pesticides and organic matters was studied in the rural water treatment plant (WTP), in Hai Duong province, Vietnam. The treatment efficiencies of the a series of processes such as coagulation/ flocculation, horizontal sedimentation, rapid sand filtration and adsorption using three types of GAC (activated carbon from bituminous coal, from bamboo and from coconut shell) and the overall treatment trains were evaluated by studying several parameters such as turbidity, COD, pesticides (chlorpyrifos, diazinon, carbofuran). Results show that the two locally produced adsorbents have a similar efficiency to commercial activated carbon for adsorption. The removal efficiency was somewhat lower for both materials, but in the same order of magnitude. The removal of pesticides and organic matter with a column filled with activated carbon derived from bamboo was found the best among the two locally produced materials, approximately 30% and 23% higher than those observed for the column filled with activated carbon from coconut shells. It concludes that bamboo-derived activated carbon adsorption can be employed on an alternative to commercial activated carbon and could be a feasible option for drinking water treatment.