Study of the distribution of 204 organic contaminants between the aqueous phase and the suspended particulate matter in treated wastewater for proper environmental control

Abstract

A distribution study of 204 organic contaminants, including polar and nonpolar pesticides, polycyclic aromatic hydrocarbons (PAHs), and phenolic compounds, between the two phases composing municipal wastewater (WW) from a small community (aqueous phase and suspended particulate matter (SPM)) has been performed to establish whether the compounds can be more prone to be in the aqueous or in the solid phase, depending on their hydrophobicity. Therefore, a general procedure is proposed to evaluate this issue. This study shows that nonpolar pesticides and PAHs are distributed between the aqueous phase and the SPM (e.g. pyrethroids are mainly found in the SPM), whereas polar pesticides and phenolic compounds are mainly present in the aqueous phase. This fact made clear the relevance of the analysis of both phases in WW samples, bearing in mind that if SPM is discarded, an important fraction of some contaminants is not determined and therefore, it does not assess the total load of pollutants discharged, underestimating the real impact on the environment.

Keywords:

• Wastewater
• Organic contaminants
• Aqueous phase
• Suspended particulate matter
• Distribution

Acknowledgments

The authors gratefully acknowledge Andalusian Regional Government (Regional Ministry of Innovation, Science, and Enterprise) and FEDER (Project Ref. P08-RNM-03892), as well as Spanish Ministry of Economy and Finance and FEDER, POCTEFEX program, (Project Ref. 0072_CAMPUS_EAGUA_2_E). NBB is grateful for her predoctoral grant from the aforementioned project. PPB acknowledges for personal funding through Juan de la Cierva Program (Spanish Ministry of Economy and Competitiveness-European Social Fund). RRG is also grateful for personal funding through Ramón y Cajal Program (Spanish Ministry of Economy and Competitiveness-European Social Fund).