Thames Water (United Kingdom)

Previously considered to be the main pathway of plastic pollution into the marine environment, large river systems are increasingly thought to act as major traps for plastic debris. The River Thames is polluted by plastic debris, including plastic drink bottles, but the proportion of items entering the North Sea is unclear. This study investigates the movement of plastic drink bottles in the Thames estuary using a combination of numerical modelling and in-situ sampling data. The model explores different factors to explain the pathways of the plastic bottles, including the bottle fullness (empty, half-full and full), the wind, and the river discharge (high/low). The model results are validated by in-situ bottle collection data from citizen science cleanups along the banks of the river. Empty bottles are found to be more affected by the wind than the river discharge and more likely to strand along the Thames estuary shoreline. Conversely, full and half-full bottles are more likely to be carried downstream by the residual currents and leave the estuary into the North Sea, particularly during periods of high river discharge. The results suggests that 53% of full bottles and 41% of half-full bottles entering the Thames estuary leave the estuary over a 150-days period, contributing to plastic pollution in the marine environment. Understanding the transport and accumulation patterns of debris in rivers, as well as gaining insight into the factors influencing their movement, helps identify optimal clean-up locations to stem the flow of plastic waste entering the marine environment.

The Thames Tideway Tunnel project is a deep tunnel system for combined sewer overflow (CSO) control in London, UK. The project controls flows from 34 CSOs by transferring flows to Beckton Sewage Treatment Works for treatment. This paper focusses on the CSO interception works undertaken at Hammersmith Pumping Station, from outline design development through to the detailed design, construction and commissioning. The development of the hydraulic and structural design for the interception of the combined sewage flows at the existing Thames Water pumping station is described. The methods of construction and logistics for these works and for the drop shaft, connection tunnel to the main tunnel and other civil engineering works are also described. There is a focus on the temporary works undertaken to enable works in the pumping station’s inlet channel and for the adjacent interception chamber, the instrumentation undertaken in the upstream catchment sewers and the close working relationship with Thames Water. Design and construction methods and working arrangements accommodated significant constraints, including limited available land for the construction site, working adjacent to a new property development, maintaining a good relationship with the local community and ensuring the pumping station remained operational at all times.

This review covers developments in and applications of XRF techniques such as EDXRF, WDXRF, TXRF, XRF microscopy using technologies such as synchrotron sources, X-ray optics, X-ray tubes and detectors in laboratory, mobile and hand-held systems.

Adenoviruses cause a range of major diseases across many diverse animal species including ruminants. They are classified into six genera in the family Adenoviridae. In deer species, two adenoviruses are currently recognized: deer adenovirus 1 in the Atadenovirus genus, and deer adenovirus 2 in the Mastadenovirus genus. Deer adenovirus 1 causes adenovirus haemorrhagic disease with high fatality in black‐tailed and mule deer in North America. Conversely, deer adenovirus 2 was incidentally detected from a healthy white‐tailed deer fawn, but experimentally it has been shown to cause pyrexia, cough and moderate to severe haemorrhage. Here, we detected a novel adenovirus, reindeer adenovirus 1, from lung lesions of a 5‐year‐old male reindeer (Rangifer tarandus). This animal presented with aspiration pneumonia and necrotizing bronchiolitis following a period of clinical weakness, nasal discharge and wasting. Histopathological examination of the lung revealed large intranuclear basophilic inclusions associated with the areas of necrotizing bronchiolitis. Next generation sequencing of the lung tissue identified a novel mastadenovirus with close similarity to deer adenovirus 2 and bovine adenovirus 3. To our knowledge, this is the first report of a deer mastadenovirus associated with necrotizing bronchiolitis in captive reindeer.

In recent years, geochemical and geophysical studies have challenged the commonly held view that the use of fossil Sahara aquifers is completely unsustainable because they have not been recharged since the last wet period of the Holocene. Here, we use gravity data and groundwater flow modeling to provide further evidence of modern recharge of the North-Western Sahara Aquifer System (NWSAS, Algeria, Tunisia, and Libya). The rainfall-recharge relationship previously established using data from the Gravity Recovery and Climate Experiment (GRACE) allows to produce a time series of the cumulated recharge of the NWSAS between 1950 and 2016. This reconstruction yields a mean value of 1.3 km3 year−1 while a near-zero recharge is obtained using GRACE data for the current decade. According to our hydrogeological model, the recharge of the confined aquifer amounts to 0.3 km3 year−1, representing almost 25% of the overall recharge. Comparison with the time evolution of pumping rates reveals that unsustainable exploitation came fully into effect around 1980, causing a tremendous decline in natural outflows. We show here that the natural outflow of the deep aquifer at Gabes (Tunisia), which partly sustains the coastal aquifer of the Djeffara plain, will vanish in the coming decade, highlighting unsustainable aquifer exploitation. Current population growth and climate change projections are both leading to a degree of groundwater over-exploitation which can only become increasingly unsustainable. Only the enforced regulation of irrigation practices supported both by current oasis pilot experiments and future fully integrated hydro-economic models will be effective in limiting this evolution.

Abstract Hexavalent chromium is difficult to remove during conventional biological wastewater treatment. This is because the hexavalent form is dissolved and is only sparingly removed by adsorption onto biomass in conventional processes. Hexavalent chromium is of particular concern because of its aquatic toxicity, and an increasing number of wastewater works have effluent discharge limits to protect receiving water courses, some as low as 8 μg Cr L−1. A relatively simple improvement to the removal of chromium could be made by switching the aluminium or ferric solution dosed at most treatment works for the removal of solids, organic load and phosphorus, to a ferrous salt. Ferrous reduces hexavalent chromium to insoluble trivalent chromium, which can be readily settled out of waste streams as a particulate. In the present study, laboratory experiments using real wastewater and ferrous doses of 10 mg Fe L−1 achieve the chromium discharge consent of 8 μg L−1 from initial solution concentrations of up to 40 μg L−1. A ferrous chloride dosing system was subsequently installed at an operational sewage treatment works that has produced an average final effluent chromium concentration of 2.4 μg L−1 (with a maximum of 4.2 μg L−1), despite influent spikes >300 μg L−1.