11 research outputs found
Pharmaceuticals in sewage systems and surface waters ā status quo
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Mineralization proximal to the final Nuna suture in northeastern Australia
Mineralization along continental suture zones is facilitated through the frequent presence of pathways from fertile mantle source regions to crustal repositories. Due to their inherent rheological weakness, these suture zones are often concealed, which hinders surface-based observations. Here, we use zircon U-Pb and sericite 40Ar/39Ar dating, and whole-rock geochemical data, to investigate the crystallization and mineralization history from a sequence of granites (sensu lato), volcanic rocks and sedimentary rocks from the AuāAgāPbāZn Empress Springs Project in northeast Australia, which are under >50 m of Phanerozoic cover and located near the interpreted ca. 1.6 Ga tectonic boundary between the North Australia Craton (Mount Isa Inlier) and Laurentia (Georgetown Inlier). Zircon U-Pb dating indicates that granite emplacement, volcanic eruptions and dolerite intrusions occurred between 1564 Ā± 6 and 1546 Ā± 13 Ma (2Ļ), corresponding to the 1560ā1550 Ma Esmeralda Supersuite and the Croydon Volcanic Group exposed in the western Georgetown Inlier. U-Pb ages from detrital zircon grains in a sedimentary rock revealed a near unimodal ca. 1560 Ma population, likely sourced from the surrounding granitic and volcanic rocks. Sericite 40Ar/39Ar dating yielded disturbed spectra with evidence for incorporation of excess radiogenic Ar, but with a probable Carboniferous to Permian age, potentially dating the timing of gold mineralization. Geochemical similarities point towards an epithermal origin for the Empress Springs Project, consistent with post-orogenic mineralization at either ca. 1560ā1550 Ma or 330ā250 Ma. It is likely that a series of west-dipping lithospheric-scale faults below the Empress Springs Project, here termed the Empress Suture Zone, demarcate the final suture zone associated with the assembly of Nuna. Reactivation of the Empress Suture Zone ~1.3 b.y. after crystallization with potential contemporaneous gold mineralization attests to its longevity for fluid mobility
Dipolar relaxation collisions in magnetically trapped 7Li
We report the measurement of the rate constant for dipolar relaxation from the (F=2, mF=2) hyperfine state of 7Li. The atoms are confined in a permanent magnet trap at a field of 103āG. The measured value of (1.05Ā±0.10)Ć10ā14ācm3/s agrees well with theory. Additionally, we determine an upper bound for the three-body molecular recombination rate constant of 10ā27ācm6/s, which is also consistent with predictions
Oxygen isotopic compositions of seawater in the Maxwell Bay of King George Island, West Antarctica
noPILLS in waters
Pharmaceuticals in the Environment (PiE) are an increasingly recognised risk to the quality of surface water and groundwater. The noPILLS project contributed towards a better understanding of the complex system of processes and ā probably more importantly ā actors that influence the presence of pharmaceutical micropollutants in waste water and, ultimately, receiving waters.Clearly, a problem as complex and wide-ranging as that of pharmaceuticals in the aquatic environment cannot be comprehensively explored by a single project. However, noPILLS aimed to provide a unique insight into the problem by first defining the range of factors affecting pharmaceuticals in the environment, together with related points for intervention, and then investigating these interventions in a multi- and inter-disciplinary fashion. In developing the concept of a āmedicinal product chainā (of processes and actors), noPILLS identified potential ālevers for interventionā towards the reduction of pharmaceutical ingress into the aquatic environment. This report describes a series of case studies of applied investigative nature along the medicinal product chain, which explored and evaluated a range of levers for intervention for their underlying efficacy, efficiency, barriers and challenges.In summary, the noPILLS project has shown that:ā¢ Pharmaceutical micropollutants are ubiquitous in the aquatic environment in the project areas, and contribute to environmental effects;ā¢ Regional differences exist in environmental conditions, as can be expected due to macro-geographical influences (landscape, climate etc), but conditions can also vary within regions and in time, with the biggest factors being influx of effluents and dilution in the environment;ā¢ A risk highlighted by noPILLS is that of antibiotic resistance developing in - or being introduced into - the aquatic environment via the sewerage network;ā¢ People, acting both as consumers/patients and as professionals, play an important role in the medicinal product chain and need to be involved more in intervention activities;ā¢ Strong regional differences exist in factors that are influenced by human behaviour, attitudes, and awareness; most likely this is primarily a result of regional differences in systems (e.g. health system, funding, waste management);ā¢ There appears to be a relatively high level of underlying willingness to ādo the right thingā both by the general public and professionals, which is largely under-utilized due to lack of information, support or means to change behaviour;ā¢ Technological interventions are effective in reducing some pharmaceutical micropollutants but present their own challenges in terms of monetary and energy costs;ā¢ Training, education and awareness raising, together with good stakeholder management and effective communication, are crucial for the success of all forms of intervention.ā¢ There appears to be no single āsilver bulletā intervention point, and the whole medicinal product chain needs to be considered for multi-point, targeted intervention