Estimation of Water Sampling Rates and Concentrations of PAHs in a Municipal Sewage Treatment Plant Using SPMDs with Performance Reference Compounds
2007 (English)In: Environmental Science and Technology, ISSN 0013-936X, Vol. 41, no 14, 5044-5049 p.Article in journal (Refereed) Published
Semipermeable membrane devices (SPMDs) were exposed at ten sampling points, each representing a different stage in the treatment process, in a municipal sewage treatment plant. Differences in SPMD uptake kinetics of polycyclic aromatic hydrocarbons (PAHs) due to variations in conditions at the sampling sites were evaluated by using five performance reference compounds (PRCs) with log Kow values of 4.20 to 6.34. PRC release rate constants (ke,PRC values) were calculated for PRCs for which 50-98% of the initial amounts were lost during the sampling period. The ke,PRC values were high, ranging from 0.08 to 0.11 day-1 for the studied PRCs, at sampling site W1 (raw sewage), the only sampling site where significant amounts of the PRCs with log Kow values >5 were released from the SPMDs. At the other sampling sites, only PRCs with log Kow values between 4.20 and 4.50 were released in significant amounts. The release rates at these sites were lowest (0.04 day-1) at sampling site W9 (the secondary clarifier) and highest (0.18 day-1) at W8 (the active sludge aeration basin). Differences between sampling rates (Rs) obtained using published laboratory-calibrated data and PRC-corrected Rs values were visualized by principal component analysis (PCA). The water concentrations of 24 studied PAHs fell substantially during the course of the sewage treatment process. However, low molecular weight PAHs were more effectively removed than high molecular weight PAHs. Significant deviations between actual and estimated water concentrations may arise unless PRC-corrected Rs values are applied.
Place, publisher, year, edition, pages
2007. Vol. 41, no 14, 5044-5049 p.
IdentifiersURN: urn:nbn:se:umu:diva-16041DOI: doi:10.1021/es070054+OAI: oai:DiVA.org:umu-16041DiVA: diva2:155714