Polybrominated diphenyl ethers in an advanced wastewater treatment plant. Part 1: Concentrations, patterns, and influence of treatment processes

Abstract

Concentrations and patterns of the mono-through deca-substituted polybrominated diphenyl ether (PBDE) flame retardants were determined in all major unit operations and processes within a tertiary-level wastewater treatment plant (WWTP) having post-filtration ultraviolet light disinfection. The results show that PBDEs do not appear to be degraded substantially or otherwise removed by wastewater treatment processes such as anaerobic, anoxic, and aerobic biological treatment, anaerobic digestion, dissolved air flotation, or sand-anthracite filtration. An overall removal efficiency of 93% was observed for PBDEs in the WWTP due to sorption onto wastewater sludges, well below that predicted by equilibrium partitioning models. High levels observed in the resulting WWTP biosolids (∼2.4 mg·kg −1 dry weight) may contaminate a wider environment through their use as a soil amendment. Lower concentrations of PBDEs contained within high volumes of aqueous WWTP effluent (∼26 ng·L −1 ) may result in a large PBDE flux into receiving waters, posing a potential threat to drinking water supplies and fisheries resources.Résumé : Les concentrations et les patrons de produits ignifugeants à base d'éthers diphényliques, polybromés, monosubstitués à décasubstitués, ont été déterminés dans toutes les opérations-procédés unitaires majeurs d'une station d'épuration des eaux usées de niveau tertiaire munie d'un système de désinfection UV post-filtration. Les résultats montrent que les éthers diphényliques polybromés ne semblent pas être substantiellement dégradés ou autrement éliminés par les procédés de traitement des eaux usées tels que le traitement biologique anaérobie, anoxique et aérobie, la digestion anaérobie, la flottation à l'air dissous ou la filtration sur sable -anthracite. Une efficacité globale d'élimination de 93 % a été observée pour les éthers diphényliques polybromés dans la station d'épuration en raison de la sorption dans les boues d'épuration, bien en deçà de ce qui est prédit par les modèles de partage à l'équilibre. Les niveaux élevés observés dans les biosolides de la station d'épuration qui en découlent (∼2,4 mg·kg −1 poids sec) pourraient contaminer un environnement plus vaste par leur utilisation en tant qu'amendement de sol. Des concentrations plus faibles des éthers diphényliques polybromés contenus dans des grands volumes d'effluent de la station d'épuration (∼26 ng·L −1 ) peuvent engendrer un grand débit d'éthers diphényliques polybromés dans les eaux réceptrices, posant ainsi un risque potentiel aux réserves d'eau potable et aux ressources halieutiques. Fig. 1. Map of the study area showing locations of major population centers and hydrologic features.

Effect of receiving environment on the transport and fate of polybrominated diphenyl ethers near two submarine municipal outfalls

“…Because PBDEs are actively sorbed on particles, they are partially transferred into the sludge that is removed from the outfall train during primary treatment. Concentrations of SPBDEs in effluent at both outfalls is at the low end of the range reported for wastewater discharges across North America (14,000-900,000 pg L À1 ) [6,[33][34][35][36], probably reflecting the limited industrial input to the wastewaters of Victoria and Vancouver. The annual total flux of PBDEs to the ocean from effluent, calculated from the concentration in wastewater and the volume of wastewater discharged each year, is 24 kg year À1 from the Vancouver outfall and 5 kg year À1 from the Victoria outfall.…”

Brominated Flame Retardants in Fish of Lake Geneva (Switzerland)

“…As in previous studies (De Wit 2002), BDE-47 was the most abundant congener among the three prevailing compounds and the ratio BDE-47:99 *2:1. This contrasts to the profile of their main source, the penta technical products with a characteristic ratio of BDE-47:99 of B1:1 (La Guardia et al 2006) and matrices representative for emissions thereof such as sewage sludge (Kupper et al 2008) or WWTP effluents exhibiting similar patterns (Rayne and Ikonomou 2005). This might be explained by degradation of BDE-99.…”

“…BDE-209 is the prevailing BDE used in Europe. Its fate in WWTPs and analyses of sewage sludge indicate that it is the dominating congener ending up in the aquatic environment (Kupper et al 2008;Rayne and Ikonomou 2005). However, BDE-209 was of minor importance contributing 5% to the total PBDE amount in fish.…”

“…PBDEs are lipophilic and bioaccumulative compounds. PBDEs are removed in WWTPs by sorption onto solids (Rayne and Ikonomou 2005) and persist when discharged to the aquatic environment.…”

Assessing reproductive and endocrine parameters in male largescale suckers (Catostomus macrocheilus) along a contaminant gradient in the lower Columbia River, USA

“…They are similar in molecular structure to PCBs and thyroid hormones (Hu et al, 2007;Lema et al, 2008), and they adsorb tightly to the organic fraction of bioavailable suspended particulates. For osprey and other biota, waste-water treatment plants along the LCR were likely a source of PBDEs (Henny et al, 2011), which are not degraded substantially or otherwise removed by processing in such plants (Rayne and Ikonomou, 2005). Although newer alternatives for flame retardants are replacing PBDEs, the decaBDEs (such as BDE-209) are still industrially produced and, along with their metabolites, will continue to bioaccumulate (Wenning et al, 2011).…”