Wastewater Treatment Lagoons: Local Pathways of Perfluoroalkyl Acids and Brominated Flame Retardants to the Arctic Environment

Abstract

Concentrations of perfluoroalkyl acids (PFAAs), polybrominated diphenyl ethers (PBDEs), and “novel” brominated flame retardants (NBFRs) were determined in lagoons processing wastewater from two high-Arctic and two sub-Arctic of Canada communities to assess the importance of local anthropogenic sources. ∑PFAAs in influent and effluent of the Arctic lagoons were within the lower end of the range of concentrations previously observed in Canadian temperate wastewater treatment plants (WWTPs). In comparison, influent and effluent concentrations of ∑PBDEs and NBFRs were significantly greater (p < 0.05) in high-Arctic lagoons compared to sub-Arctic and temperate plants. The surprisingly elevated concentrations of PBDEs and NBFRs in high-Arctic lagoons were probably related to high organic matter found in Arctic wastewater due to lower consumption of potable water leading to less dilution compared to temperate regions. Although PFAAs also sorb to solids, the wastewater samples were filtered prior to analysis of PFAAs (but not PBDEs and NBFRs), which likely reduced the impacts of solids on the results for PFAAs. Based on an extrapolation of per capita mass effluent loadings of the four Arctic lagoons, mass loadings to the Arctic of Canada via WWTP effluent were estimated as 1405 g/year and 549 g/year for ∑PFAAs and ∑PBDEs, respectively.

Long-Range Transport, Trophic Transfer, and Ecological Risks of Organophosphate Esters in Remote Areas

“…53 With the augmented human activities in the polar regions, local emission sources of legacy and emerging POPs have been found in air, soil, water, sediment, and aquatic organisms in the polar regions. 54,55 OPEs are widely used in household and industrial products such as plastics, furniture, textiles, electronic equipment, building materials, hydraulic fluids, and floor finishes, basically covering all aspects of human production and life. 7,56 In the extremely dry and cold environments in the polar regions, building and decoration materials, instruments, electronic equipment, and many thermoplastics used in research stations may contain considerable flame retardants, 57 especially OPEs.…”

Assessing the Ecological Risks of Per‐ and Polyfluoroalkyl Substances: Current State‐of‐the Science and a Proposed Path Forward

“…In addition, these same regions contain non-military airports of various sizes as well as a limited number of population centers with wastewater treatment plants that may not efficiently remove PFAS.. There are several papers available that discuss some of the potential implications of these installations relative to other contaminants, including PFAS (Stow et al 2005;Poland et al 2001;Gewurtz et al 2020).…”

Insights into the Occurrence, Fate, and Impacts of Halogenated Flame Retardants in Municipal Wastewater Treatment Plants

“…Notably, negative removal efficiencies have been observed for some HFRs. In particular, the ClOPFRs were found to have negative removal in almost half of studies investigating these compounds. ,,,, Negative removal can be largely attributed to the direct release of nonchemically bound additive HFRs from plastic fragments in the wastewater. ,, Alternately, negative removal could also be an artifact of sampling schemes; for example, grab sampling, which cannot detect real-time variations in HFR concentrations and hydraulic retention time (HRT) in the treatment process, is frequently used to collect wastewater samples from WWTPs. ,,, The concentrations of many pollutants, including some HFRs, can vary considerably in the influent throughout the day, leading to inaccurate estimations of removal efficiency in simple comparisons of influent and effluent concentrations. Composite sampling or grab sampling that accounts for HRT can be used to increase the reliability of removal efficiency estimations.…”

“…34,118,119 Alternately, negative removal could also be an artifact of sampling schemes; for example, grab sampling, which cannot detect real-time variations in HFR concentrations and hydraulic retention time (HRT) in the treatment process, is frequently used to collect wastewater samples from WWTPs. 33,42,43,85 The concentrations of many pollutants, including some HFRs, can vary considerably in the influent throughout the day, 120 leading to inaccurate estimations of removal efficiency in simple comparisons of influent and effluent concentrations. Composite sampling or grab sampling that accounts for HRT can be used to increase the reliability of removal efficiency estimations.…”

“…Volatilization, abrasion, and weathering are the major mechanisms of HFRs migration from consumer products to the environment, which can be accelerated by fragmentation or biological and chemical transformation. − HFRs have been detected in remote regions, such as the arctic and the Qinghai-Tibet Plateau, ,, where anthropogenic activities are rare, indicating long-distance transport of HFRs by natural processes (e.g., by snow, rain, adhesion to aerosolized particulates, and oceanic transport). − Extensively used HFRs have also been widely detected in wastewater treatment plants (WWTPs) around the world. − HFRs can enter the wastewater treatment stream via disposal of cleaning fluids by manufacturing facilities, disposal of consumer products, landfill leachate, and precipitation. ,− Conventional WWTPs are not designed to remove HFRs and only minor to moderate fractions (<80%) of the HFRs entering WWTPs are biotransformed during treatment, with most being adsorbed to the wastewater treatment solids and the remainder being discharged with the effluent. , Over 300 billion tons of municipal wastewater was discharged in 2010 worldwide, much of which is introduced into soils or terrestrial and marine waters. Hence, WWTPs represent an important source of environmental HFRs contamination and the contribution of WWTPs to HFRs deposition is an issue of growing concern. ,,,− …”