Contaminant mobility as a result of sediment inundation : literature review and laboratory scale pilot study on mining contaminated sediments

This report presents a literature review of soil and sediment inundation methodologies and describes a pilot scale laboratory inundation study. Changing weather conditions, subsequent flooding events, and the increased frequency of such events both in the UK and worldwide is highlighting the need to research the area of contaminant mobility from soils and sediments under inundated conditions. The findings of such investigations impact on a wide variety of sectors, including human and ecological health, agriculture, building, transport, world economy and climate change. Standardised methodologies for the investigation of contaminant mobility resulting from soil/sediment inundation episodes are not available. Most research has been conducted in the agricultural sector for nutrient transport, as part of soil fertility and plant nutrition studies. Only recently has work been undertaken for studying potentially harmful element transport in inundated sediments/soils. A pilot scale laboratory study was undertaken using contaminated bank sediment samples collected from the Rookhope Burn catchment, Northern England, UK, with the aim to examine the extent of contaminant mobilisation from flooded sediments. The catchment has been affected by historical mining and processing of lead and zinc ore and is representative of several catchments affected by the environmental legacy related to mining in the Northern Pennine Orefield. Bank sediment Pb and Zn concentrations were found significantly above both the TEL and PEL sediment quality criteria, posing potentially a significant hazard to aquatic organisms. The source of the Pb and Zn in the sediments is related to the underlying mineralisation, mining activities and mine water discharges in the catchment. Abundances of original sulphide ore and authigenic metal-bearing phases were expected to vary through the catchment. The study design simulated rising flood water, a slow saturation of the sediment in order to induce a slow change in physico-chemical properties, followed by a 3 month (88 day) stagnation period. Natural day-night cycles were simulated by undertaking the study on the bench top during the winter of 2009/2010 (November to February). The chemical changes in the inundation water during the experiment were monitored and the sediment pore water at the end of the inundation period analysed. The inundation water pH remained alkaline to neutral, while redox measurements indicated oxic conditions in the water column throughout the inundation period. The pilot study showed that inundation of river bank sediments from the Rookhope Burn may be a significant pathway for contaminants in the catchment and that mobilisation from the sediments may pose a hazard to environmental receptors in the area, particularly with respect to Pb and Zn contamination. The different degrees and different rates of metal losses to the overlying water column observed during the flooding of the Rookhope Burn bank sediments demonstrated that the significance of metal mobilisation was dictated by the sediment composition. The inundation water composition monitored during the sediment flooding was used to indirectly infer possible processes that control contaminant fluxes from the sediments to the overlying water. Dissolved Pb concentration in the inundation water reflected the original concentration in the solid material and in sediments that had XRD-detectable galena and cerussite the dissolved Pb concentration reached a maximum value of 395 μg l-1. Cerussite, which is commonly formed as coatings on galena during the sulphide weathering, was close or supersaturated in those solutions, suggesting that the lead carbonate mineral phase provided a continuous source of Pb to these solutions. The initial dissolved Zn in the inundation waters was independent of the original concentration in the sediments. Sediments downstream a mine water discharge showed a greater availability of easily mobilised Zn, producing high initial Zn concentration in the inundation water, despite the relatively low Zn concentration in the inundated sediment. The Zn/SO4 and Cd/Zn molar ratios were both consistent with sphalerite mineral oxidation. The final inundation water solutions had the highest Zn concentrations for those sediment samples where sphalerite was detected by XRD. Redox sensitive elements such as Fe and Mn could not unequivocally indicate the presence of reducing conditions within the flooded sediments and the redox measurements were carried out only in the overlying water column (ORP above 200-350 mV). Low organic matter content and sandy texture would not have favoured the rapid formation of an anoxic layer. Yet, only extending the ORP measurements to the submerged sediment would determine the presence of flooding-induced reducing conditions. Reductive dissolution of Mn oxyhydroxides would result in release of Mn into solution, along with other trace metals, such as Pb and Zn. Mn increased in the inundation water throughout most or all the inundation period for some of the studied sediments. Their final pore water composition was significantly enriched in Mn (1300- 6500 μg l-1). Saturation indices indicated both rhodocrosite (MnCO3) and Mn oxides reached saturation. Therefore, it was not possible to preclude either the role of rhodocrosite as solubility controlling solid phase or the reductive dissolution of Mn oxides for accounting the enhanced Mn concentrations in the pore water and overlying water column without a better characterisation of the solid phase and monitoring of the sediment redox conditions. Amendments to the inundation test design have been recommended, which comprise: set-up to allow for the continuous monitoring of pore water dynamics and allow for the collection of pore water at the different times and measurement of pore water pH and Eh; inclusion of a blank test cell, to test the influence of the properties and the volume of the inundation water; inclusion of flow-cell tests to assess the influence of moving or stagnant inundation water; the inclusion of abiotic blanks to identify the role microbes play in the solubilisation of contaminants. complementary characterisation of the solid phase material and metal distribution in the sediment before and after the inundation experiment

Analysis of the retail survey of products that carry welfare- claims and of non-retailer led assurance schemes whose logos accompany welfare-claims.

This report serves two aims. Firstly, this report contains analysis of the retail audit (sub-deliverable 1.2.2.1) of welfare-friendly food products in the 6 study countries. The report gives the results of an emerging comparative analysis of the ‘market’ for welfare-friendly food products in the 6 study countries. It also outlines ‘non-retailer’ led schemes1 whose products occurred in the study. In this way, an emerging picture of the actual product ranges, that make claims about welfare-friendliness, will be drawn based on fieldwork carried out from November 2004 until April 2005. Also, the report explores how the different legislative and voluntary standards on animal welfare compare across different countries and how these actively advertise their welfare-friendlier component to consumers through food packaging. <br/

Wind information display system user's manual

The Wind Information Display System (WINDS) provides flexible control through system-user interaction for collecting wind shear data, processing this data in real time, displaying the processed data, storing raw data on magnetic tapes, and post-processing raw data. The data are received from two asynchronous laser Doppler velocimeters (LDV's) and include position, velocity and intensity information. The raw data is written onto magnetic tape for permanent storage and is also processed in real time to depict wind velocities in a given spacial region

When and where? Pathogenic Escherichia coli differentially sense host D-serine using a universal transporter system to monitor their environment

Sensing environmental stimuli is critically important for bacteria when faced with the multitude of adversities presented within the host. Responding appropriately to these signals and in turn integrating these responses into the regulatory network of the cell allows bacteria to control precisely when and where they should establish colonization. D-serine is an abundant metabolite of the human urinary tract but is a toxic metabolite for Escherichia coli that lack a D-serine tolerance locus. Enterohaemorrhagic E. coli (EHEC) cannot catabolize D-serine for this reason and colonize the large intestine specifically, an environment low in D-serine. EHEC can however use D-serine sensing to repress colonization thus signaling the presence of an unfavorable environment. In our recent work (Connolly, et al. PLoS Pathogens (2016) 12(1): e1005359), we describe the discovery of a functional and previously uncharacterized D-serine uptake system in E. coli. The genes identified are highly conserved in all E. coli lineages but are regulated differentially in unique pathogenic backgrounds. The study identified that EHEC, counter-intuitively, increase D-serine uptake in its presence but that this is a tolerated process and is used to increase the transcriptional response to this signal. It was also found that the system has been integrated into the transcriptional network of EHEC-specific virulence genes, demonstrating an important pathotype-specific adaptation of core genome components

The performance of farm animal assessment

This paper argues that the current drive towards greater use of animal-based measures for welfare assessment raises important issues for how farm visits by welfare assessors are performed. As social scientists, we employ a number of contemporary social science ideas to offer a new approach to examining the practice and performance of farm animal assessment. We identify key findings from a recent study of contemporary farm assessment and speculate upon what some of the challenges of introducing animal-based measures may be. We conclude by arguing for a greater awareness of how sets of knowledge are made, circulated, practiced and become an integral component of the procedures, practices and discourses around farm animal welfare assessment in farm assuranc

From screen to target: insights and approaches for the development of anti-virulence compounds

A detailed understanding of host-pathogen interactions provides exciting opportunities to interfere with the infection process. Anti-virulence compounds aim to modulate or pacify pathogenesis by reducing expression of critical virulence determinants. In particular, prevention of attachment by inhibiting adhesion mechanisms has been the subject of intense research. Whilst it has proven relatively straightforward to develop robust screens for potential anti-virulence compounds, understanding their precise mode of action has proven much more challenging. In this review we illustrate this challenge from our own experiences working with the salicylidene acylhydrazide group of compounds. We aim to provide a useful perspective to guide researchers interested in this field and to avoid some of the obvious pitfalls

The retail of welfare-friendly products: A comparative assessment of the nature of the market for welfare-friendly products in six European Countries

This paper attempts to describe the market for welfare-friendly foodstuffs within larger retailing trends in six study countries in Europe (Norway, Sweden, Italy, France, the Netherlands and the UK). This is based on the findings to date from the work carried out by the work package 1.2 whose aims are to study the current and potential market for welfare-friendly foodstuffs. The aims of the current empirical stages of work package 1.2 are focussed on – what do retailers communicate to consumers about animal welfare? How is animal welfare framed? Are welfare-claims used on their own or within broader issues of quality

Analysis of selective chopper radiometer data

Data from SCR-B on Nimbus 5 have been processed to yield global, orbital temperatures at 10, 5, 2, 1, and 0.4 mb for the period January 1977 through April 1978 under the current task. In addition gridded values at 10 deg latitude by 20 deg longitude were prepared by space-time interpolation for the period January 1975 through April 1978. Temperature retrieval was based on regression of radiances against Meteorological Rocket Network data, with regressions recomputed at approximately six-month intervals. This data now completes a consistent time series from April 1970 to April 1978 for all available radiance data from SCR A and SCR B on Nimbus 4 and 5. The processing details for the current period are discussed, but is also applicable to the previous data periods. The accuracy of the temperature retrievals for each 6-month period for the entire eight years is given in the Appendices

Tracking elusive cargo: Illuminating spatio-temporal type 3 effector protein dynamics using reporters

Type 3 secretion systems (T3SS) form an integral part of the arsenal of many pathogenic bacteria. These injection machines, together with their cargo of subversive effector proteins are capable of manipulating the cellular environment of the host in order to ensure persistence of the pathogen. In order to fully appreciate the functions of Type 3 effectors it is necessary to gain spatio-temporal knowledge of each effector during the process of infection. A number of genetic modifications have been exploited in order to reveal effector protein secretion, translocation and subsequent activity and localisation within host cells. In this review, we will discuss the many available approaches for tracking effector protein dynamics and discuss the challenges faced to improve the current technologies and gain a clearer picture of effector protein function