A seeded ambient temperature ferrit process for the treatment of AMD waters: Magnetite formation in the presence and absence of calcium ions under steady state operation

An ambient temperature ferrite process has been developed for the removal of iron and non-ferrous metals from AMD waters. The process involves the controlled formation of magnetite (Fe3 O4 ) that has the capacity to substitute divalent and trivalent cations as part of the lattice, thus forming a stable easy-to-separate ferrite. This paper reports on continuous operations of the process in the absence and presence of Ca2+, which is well known to impede ferrite formation. In the first instance, the process involves the precipitation of hydroxy-metals at pH 10.5 and their subsequent adsorption onto magnetite seed in a contact stabilisation reactor. Second, liquid-solid separation is effected and the solid fraction is subsequently treated in an oxidising reactor in which a fraction of the ferrous species is oxidised to an intermediate ferric precipitate. Finally, both ferrous and ferric species undergo crystalchemical processing and are incorporated into stable magnetite. Results indicate that Ca2+ interference can be overcome by maintaining a high ratio of precipitated ferrous species to dissolved Ca2+. It was found that in order to attain the required high Fe2+:Ca2+ ratio, the solid ferrous-hydroxy species concentration in the oxidation reactor should be maintained at above 1 200 mg Fe/l. Ferrous to calcium ratios greater than 3 were found to favour magnetite formation. In the absence of Ca2+, a solid ferroushydroxy species concentration of approximately 500 mg/l was sufficient for magnetite formation. Operating the process at ferroushydroxy concentrations of lower than 1 200 and 500 mg/l in the presence and absence of calcium respectively enhanced the formation of other iron oxides, primarily goethite. In all experiments the iron concentration in the effluent was less than 1 mg/l, the sludge volume index (SVI) extremely low (< 4 ml/g) and the percentage of ferrous-hydroxy species in the sludge can be reduced to about 1%. These features, together with the potential to incorporate heavy metals into a stable compound, make the process very promising for AMD treatment

Electrical Transport, Magnetism, and Spin-state Configurations of High-Pressure Phases of FeS

Both the nature of the electrical transport and magnetism of high-pressure phases of FeS have been elucidated in relation to the spin-state configuration of Fe. This has been achieved by combined 57FeMössbauer spectroscopy and resistance measurements on samples pressurized in miniature gem-anvil pressure cells to ∼12 GPa in the range 300–5 K. Hexagonal FeS in the range 3–7 GPa exhibits magnetic nonmetallic behavior, whereas monoclinic FeS beyond ∼7 GPa is diamagnetic and nonmetallic. This is compelling experimental evidence to show that, along the room-temperature isotherm, hexagonal FeS has thermally activated charge carriers and a high-spin magnetic-electronic configuration, whereas monoclinic FeS adopts a magnetically quenched low-spin state and concomitant filled valence band

Seeding Change by Visioning Good Anthropocenes

Although we are surrounded by dystopian stories about the age of the Anthropocene, the future does not have to be bleak. Seeds of alternative good futures occur in many places around the world and we can use these to help us think more creatively about pathways to more desirable futures in the Anthropocene. This paper describes the Seeds of Good Anthropocenes (SOGA) project that aims to identify where elements of Good Anthropocenes (‘seeds’) currently exist on the planet and how they can be used to help us envision pathways towards new, positive futures for the Earth and humanity. Each of the seeds is a potential solution that could help to shift us onto a more sustainable trajectory that will ensure both planetary and human wellbeing. The project has developed and combined novel visioning tools that engage a broad set of stakeholders in identifying potentially game-changing seed initiatives, and exploring how these could develop and combine to create radically alternative futures. This new scenario approach has been used in intergovernmental processes such as the UN Environment’s Global Environment Outlook (GEO) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). By tapping into creativity and ingenuity, the SOGA scenario process provides a set of methodological tools through which we can think in new ways about how to navigate towards more desirable futures, starting with the pockets of these futures that are already with us in the present

Pressure-induced amorphization and polyamorphism in one-dimensional single crystal TiO2 nanomaterials

The structural phase transitions of single crystal TiO2-B nanoribbons were investigated in-situ at high-pressure using the synchrotron X-ray diffraction and the Raman scattering. Our results have shown a pressure-induced amorphization (PIA) occurred in TiO2-B nanoribbons upon compression, resulting in a high density amorphous (HDA) form related to the baddeleyite structure. Upon decompression, the HDA form transforms to a low density amorphous (LDA) form while the samples still maintain their pristine nanoribbon shape. HRTEM imaging reveals that the LDA phase has an {\alpha}-PbO2 structure with short range order. We propose a homogeneous nucleation mechanism to explain the pressure-induced amorphous phase transitions in the TiO2-B nanoribbons. Our study demonstrates for the first time that PIA and polyamorphism occurred in the one-dimensional (1D) TiO2 nanomaterials and provides a new method for preparing 1D amorphous nanomaterials from crystalline nanomaterials.Comment: 4 figure

Wigner-Mott insulator-to-insulator transition at pressure in charge-ordered Fe2OBO3

International audienc

Generating evidence on the use of Image and performance enhancing drugs in the UK: Results from a scoping review and expert consultation by the Anabolic Steroid UK network.

Background The use of anabolic androgenic steroids (AAS) and associated image and performance enhancing drugs (IPEDs) is now a global phenomenon. There is a need to develop evidence to support the development of interventions to prevent the commencement of use, to minimise the potential harms or to support those in their cessation of use. While the United Kingdom (UK) is no exception to this issue, its public health and legislative response to the phenomenon differs to other countries and requires the examination of research specific to the UK. Therefore, a scoping review has been conducted to examine the recent relevant literature to help inform the development and evaluation of effective interventions to reduce the harmful use of IPEDs. Methods A comprehensive search strategy was developed for multiple bibliographic databases, supported by and iterative citation searching process and complimented by expert input from the Anabolic Steroid UK Network. Research conducted by or UK academics or within the UK were eligible, if published in the previous five years. Results 3 In total 87 eligible outputs were identified, including 26 review articles, 25 qualitative papers and 24 quantitative papers. together with small numbers of clinical studies/case reports (6) and commentaries/correspondence (6). The most common topics of research were public health, treatment and harm reduction (41), followed by studies focusing on epidemiology, sub-groups of people using IPEDs and motivations for use (34). The studies illustrated the diverse populations of people who use a range of enhancement drugs including concomitant psychoactive drug use. A number of papers focused on blood borne viruses and associated issues, while others reported on the uptake of needle and syringe programmes. No effectiveness evaluations related to any aspect of treatment, harm reduction or other intervention were published during study period. Conclusion There is a need for the development of effectiveness evaluations of current interventions and any future service provision for people using image and performance enhancing drugs. While there have been no studies of this nature to date, this review illustrates the rich data that has been gathered through diverse methodologies, that will assist in the development of future effectiveness evaluations

Discriminative characteristics of marginalised novel psychoactive users: A transnational study

New psychoactive substances (NPS) continue to be considered as a major public health concern in many European countries. The study was implemented within the framework of a transnational project of six European countries (Germany, Hungary, Ireland, Netherlands, Poland, Portugal). Our aim here is to report on the distinct and differentiating characteristics of marginalised NPS users. Three subgroups of a total of 3023 adult NPS users (socially marginalised, night life, online community) were examined regarding their socio-demographic characteristics, substance use, and external motives towards NPS use. Poland and Hungary reported higher rates of NPS use in comparison to traditional controlled drugs. The external/contextual motives did not play a central role in the background of NPS use, the least important motives were alleged legality and non-detectability of these substances. Marginalised (defined as those accessing low threshold harm reduction services) users’ substance use patterns are different from the other two groups in terms of showing more intense and riskier drug use. The most important variables which contributed to be categorised as a marginalised NPS user were lower level education, being older, having an unfavourable labour market position and using drugs intravenously. Contextual motives did not play a decisive role in being categorised as a marginalised user when drug use pattern was controlled. These identified discriminative features of marginalised drug users should inform policy makers to develop and implement tailor-made interventions targeting this user group to successfully tackle the elevated public health concerns associated with NPS use