Pharmaceutical adsorption from the primary and secondary effluents of a wastewater treatment plant by powdered activated carbon

Abstract

AbstractThis study investigated the powdered activated carbon (PAC) adsorption of 13 pharmaceuticals from the primary (and secondary) effluents of a wastewater treatment plant. In addition to fresh PAC, PAC that was previously used for pharmaceutical elimination from the secondary effluent was also examined for its reuse potential in the primary effluent. The results showed a comparably negligible pharmaceutical uptake by fresh and used PACs in the primary effluent, in contrast to a substantial uptake by both PACs in the secondary effluent. This result indicated a severe adsorption competition induced from the primary effluent organic matter, i.e. the considerably higher constituents of low molecular and hydrophobic components. Furthermore, the competition effect even resulted in a desorption of the negatively charged pharmaceuticals from the used PAC into the primary effluent. It was concluded that adding fresh PAC to the secondary effluent is preferred and that recycling the used PAC into the activated ...