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Abstract: The discharge of treated wastewater into natural water bodies occurs worldwide; if drinking water is then extracted downstream, there is potential for micropollutants that are not fully mineralized in the wastewater treatment process to enter municipal drinking water. In Australia, drinking water treatment is typically a mixture of basic technologies such as flocculation and slow sand filtration; technologies that are not specifically designed to remove micropollutants. However, there is little awareness in Australia of the potential risk that upstream wastewater discharges may impart to the security and quality of downstream drinking water supplies. We apply a direct inductively coupled plasma mass spectrometry technique to determine the discharge of anthropogenic gadolinium from a wastewater treatment plant in Toowoomba, Queensland, Australia, that discharges into the small (147km2) catchment of Gowrie Creek. We then continue to measure the concentrations of this wastewater tracer as Gowrie Creek flows downstream into the Condomine River, and to a community 100km away where drinking water is extracted. Using this tracer, we demonstrate that the community has a detectable wastewater contribution within their surface drinking water supply. [ABSTRACT FROM AUTHOR]

Abstract: Wastewater effluent is known to contain macro and micropollutants, which may be deleterious to environmental health. One such class of micropollutants is chelated gadolinium, which are used as MRI contrast agents. As these MRI contrast agents can be assumed to behave conservatively during estuarine mixing, it is possible to calculate how much wastewater is represented in any particular sample. In this study, the percentage contribution of wastewater at specific locations in Moreton Bay, Qld, were determined by calculating the additional anthropogenic gadolinium contribution to the total rare earth element concentrations. Wastewater contributions were measured at concentrations as low as 0.2%, demonstrating the applicability of this technique for wastewater effluent plume mapping. [Copyright &y& Elsevier]

Abstract: This paper examines the fate of perfluorinated sulfonates (PFSAs) and carboxylic acids (PFCAs) in two water reclamation plants in Australia. Both facilities take treated water directly from WWTPs and treat it further to produce high quality recycled water. The first plant utilizes adsorption and filtration methods alongside ozonation, whilst the second uses membrane processes and advanced oxidation to produce purified recycled water. At both facilities perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), perfluorohexanoic acid (PFHxA) and perfluorooctanoic acid (PFOA) were the most frequently detected PFCs. Concentrations of PFOS and PFOA in influent (WWTP effluent) ranged up to 3.7 and 16ngL−1 respectively, and were reduced to 0.7 and 12ngL−1 in the finished water of the ozonation plant. Throughout this facility, concentrations of most of the detected perfluoroalkyl compounds (PFCs) remained relatively unchanged with each successive treatment step. PFOS was an exception to this, with some removal following coagulation and dissolved air flotation/sand filtration (DAFF). At the second plant, influent concentrations of PFOS and PFOA ranged up to 39 and 29ngL−1. All PFCs present were removed from the finished water by reverse osmosis (RO) to concentrations below detection and reporting limits (0.4–1.5ngL−1). At both plants the observed concentrations were in the low parts per trillion range, well below provisional health based drinking water guidelines suggested for PFOS and PFOA. [ABSTRACT FROM AUTHOR]

Stable gadolinium (Gd) complexes have been used as paramagnetic contrast agents for magnetic resonance imaging (MRI) for over 20 years, and have recently been identified as environmental contaminants. As the rare earth elements (REE), which include Gd, are able to be measured accurately at very low concentrations (e.g. Tb is measured at 7 fmol/kg in this study) using inductively coupled plasma mass spectrometry (ICP-MS), it is possible to determine the fate of this class of compounds during the production of purified recycled water from effluent. Coagulation and microfiltration have negligible removal, with the major removal step occurring across the reverse osmosis membrane where anthropogenic Gd (the amount of Gd attributable to MRI contrast agents) is reduced from 0.39 nmol/kg to 0.59 pmol/kg, a reduction of 99.85%. The RO concentrate has anthropogenic Gd concentrations of 2.6 nmol/kg, an increase in concentration in line with the design characteristics of the plant. The increased concentration in the RO concentrate may allow further development of anthropogenic Gd as a tracer of the fate of the RO concentrate in the environment.