Characterisation of volatile organic contaminants after different pretreatment systems in reclaimed wastewater

Abstract

Several lines of reclamation has been tested in the Palamós/Vall-Llobrega, Spain wastewater treatment plant (WWTP). Each line consists on a filtration treatment and a disinfection system. Different lines have been tested in order to establish the fate of volatile organic compounds (VOCs) during wastewater treatment and reclamation procedures. The studied technologies after a classical activated sludge treatment were infiltration-percolation, ring filtration, sand filtration, and coagulation-floculation plus sand filtration. Analysis of VOCs were performed at the different stages of the treatment by closed loop stripping analysis (CLSA) method which is able to determine compounds at trace levels (ng/L) and covers a wide range of organic pollutants. The CLSA extracts were further analyzed by GC/MS. Organic compounds such as tert-butyl alcohols and ketones, musks; iso-propyl fatty acids, and other minor components were regularly identified in the influent. Removal of all pollutants was partially achieved by all methodologies tested except the musk compounds which proved to be recalcitrant in all cases but one. The sole metodology that exhibited a total elimination of all organic compounds identified in the effluent including musks was infiltration-percolation.