Coal mine drainage ochre is a ferruginous precipitate that forms from mine water in impacted watercourses and during treatment. With thousands of tonnes per annum of such ochre arising from mine water treatment in the UK alone, management of these wastes is a substantive issue. This paper demonstrates that the ochre from both active and passive treatment of coal mine drainage can be transformed into an effective water treatment reagent by simple acid dissolution and that the reagent can be used for the removal of dissolved phosphorous from municipal wastewater and zinc from non-coal mine waters. Ochre is readily soluble in H2SO4 and HCl. Ochre is more soluble in HCl with solubilities of up to 100 g/L in 20% (w/w) HCl and 68 g/L in 10% (w/w) H2SO4. For four of the eight tested ochres solubility decreased in higher concentrations of H2SO4. Ochre compositional data demonstrate that the coal mine ochres tested are relatively free from problematic levels of elements seen by other authors from acid mine drainage-derived ochre. Comparison to British Standards for use of iron-based coagulants in drinking water treatment was used as an indicator of the acceptability of use of the ochre-derived reagents in terms of potentially problematic elements. The ochre-derived reagents were found to meet the 'Grade 3' specification, except for arsenic. Thus, for application in municipal wastewater and mine water treatment additional processing may not be required. There was little observed compositional difference between solutions prepared using H2SO4 or HCl. Ochre-derived reagents showed applicability for the removal of P and Zn with removals of up to 99% and 97% respectively measured for final pH 7-8, likely due to sorption/coprecipitation. Furthermore, the results demonstrate that applying a Fe dose in the form of liquid reagent leads to a better Fe:P and Fe:Zn removal ratio compared to ochre-based sorption media tested in the literature.

On 7 April 2019 Intelsat 29e, a communications satellite at geostationary orbit, experienced an anomaly resulting in a fuel leak. Two days later communication with the satellite was lost, and as revealed by ground based optical telescopes, a number of pieces of debris were seen emanating from the satellite in the days that followed (https:// www.spaceflightnow.com/2019/04/15/stricken-with-fuel-leak-intelsat-29e-seen-drifting-in-geostationary-orbit/). ExoAnalytic's observations are available on YouTube (https://www.youtube.com/watch?v=aqPrVn71IqY). On 10 April Intelsat issued a Press Release reporting a service outage which affected maritime, aeronautical and wireless operator customers in the Latin America, Caribbean and North Atlantic regions. They also described their efforts to migrate customers to other satellites (https://www.intelsat.com/news/press-release/intelsat-29e-service-outage/). On 18 April Intelsat declared the satellite a total loss. The satellite now appears to be tumbling out of control and drifting toward the East around the geostationary arc.

No abstract

During European Space Weather Week 15 two plenary sessions were held to review the status of operational space weather forecasting. The first session addressed the topic of working with space weather service providers now and in the future, the user perspective. The second session provided the service perspective, addressing experiences in forecasting development and operations. Presentations in both sessions provided an overview of international efforts on these topics, and panel discussion topics arising in the first session were used as a basis for panel discussion in the second session. Discussion topics included experiences during the September 2017 space weather events, cross domain impacts, timeliness of notifications, and provision of effective user education. Users highlighted that a severe space weather event did not necessarily lead to severe impacts for each individual user across the different sectors. Service providers were generally confident that timely and reliable information could be provided during severe and extreme events, although stressed that more research and funding were required in this relatively new field of operational space weather forecasting, to ensure continuation of capabilities and further development of services, in particular improved forecasting targeting user needs. Here a summary of the sessions is provided followed by a commentary on the current state-of-the-art and potential next steps towards improvement of services.

Blenkinsopp Colliery (Northumberland, UK) was the second-last underground coal mine in production in the former Great Northern Coalfield of England. The immediate roof beds of the single worked seam included a thick limestone bed; an unusual occurrence in UK coal mines. Hydrogeochemical investigations of the water encountered underground during the working of the mine revealed that specific qualities of water were logically related to details of the flowpaths the waters were inferred to have taken to reach the accessible sampling points. Working from this information, and taking into account observations of mineralogical and mining engineering aspects of the workings, a conceptual model was developed which assisted in predicting the likely response of the colliery to abandonment and flooding. In particular, it was predicted that, despite the presence of limestone in the roof and in goaf materials, the early outflows from the mine would be sufficiently acidic that they would require active treatment. Flooding of the mine is now complete, and post hoc analyses have largely vindicated earlier predictions of the time it would take for the mine to flood to surface, and the approximate post-flooding flow rates. The prediction that the water would be strongly net-acidic has also been borne out by observations: it is clear that the presence of limestone in a mined sequence is no guarantor of a neutral-pH discharge. However, the extremely high iron concentrations encountered post-flooding (≤ 1000 mg/l Fe +2) have exceeded expectations by a factor of around 3.3. Improvement in the understanding of likely quality, perhaps by means of tracer tests in recently flooded workings, could help reduce risks related to treatment scheme design, thus enabling more robust design and budgeting to be carried out as early as possible in the postclosure management period.