ABSTRACT
Activated carbon is one of the most versatile materials used for water filtration. With the latest surface modification methods and different types of carbon precursor available, carbon-based filters can meet emerging standards in water purification and related regulations. Shapes, sizes, and structures of the activated carbon are the ones making it an exceptional microporous material for water purifiers. Activated carbons manufactured by the conventional routes of carbonization and activation are subjected to additional chemical treatments to enhance the adsorption and catalytic characteristics of the material towards specific contaminants. Surface oxygen groups are by far the most important in influencing the adsorption behavior of activated carbon. The oxygen functional groups are created by treating carbon with either oxidative reagents or atmospheric plasma processing. On the other hand, for the contaminants such as chloramine and hydrogen sulfide in drinking water, carbon is treated with alkaline reagents to create nitrogen functional groups in the basal plane of the material, which results in the catalytic reduction of chloramines. Further, carbon is impregnated with silver or transitional metals for the removal of microbial contaminants. This chapter describes the surface modification techniques and the reaction mechanisms involved in the removal of different contaminants by the surface modified carbon for water purification.
