Dissolved and acid available particulate beryllium in eastern UK surface waters

Abstract

The concentrations of beryllium (Be) in surface waters are presented for major water quality surveys of eastern UK rivers, based on extensive work within a major environmental programme, the Land Ocean Interaction Study (LOIS). Two measurements were made, one for dissolved Be (i.e. the fraction that can pass through 0.45-μm membrane filters) the other for acid available total Be (dissolved Be plus the fraction of particulate Be that can be leached by a 1% v/v concentrated nitric acid solution). Dissolved Be concentrations are generally less than 1 μg l −1 with a mean of approximately 0.02 μg l −1, but higher values occur across the eastern UK rivers between 16th October and 7th November 1995 under neutral to alkaline conditions where Be would not be expected to be mobile. The higher values vary from river to river and there is a marked increase from north to south with particularly high concentrations (up to 29 μg l −1) for the industrial and urban impacted rivers of the southern Humber basin. The results show a major increase in dissolved Be at a time of exceptional drought conditions and climate instability, which seems to be linked to industrial/urban catchment systems. The average dissolved Be flux is 0.22 g ha −1 year −1 with a range in mean across the sites of 0.08–0.45 g ha −1 year −1. Without the period of enhanced Be concentrations, the Be flux through the period would have been approximately 40% less. There is no clear distinction between the dissolved Be flux for the rural and urban/industrial catchment systems. Acid available particulate Be (AAP Be) concentrations are low across the eastern UK rivers, they range between 0 and 1.33 μg l −1 with a mean of 0.02 μg l −1 and the highest concentrations occur for the industrial/urban rivers (approximately twice the levels occurring within the rural rivers). The AAP Be concentrations are linearly correlated with the concentrations of suspended sediment, particulate organic carbon, particulate nitrogen, particulate phosphorus, and the AAP for several transition metals (Al, Co, Cr, Fe, Mn, Ni and Y), and the lanthanides. This reflects the nature of the catchment sources of particulate material (soil erosion and pollutant sources) and the hydrogeochemistry of Be with the high potential for hydrolysis and hydrogen bonding due to its small atomic size and high surface charge density. The acid available particulate flux averages approximately 0.42 g ha −1 year −1 with a range in mean across the sites of 0.14–1.2 g ha −1 year −1. The highest flux occurs for a river with a flood plain contaminated by spoil from historic mining of lead–zinc deposits, but there is no clear separation between the rural and the industrial/urban impacted catchments. The results indicate a potential and most unexpected dissolved Be stress to lowland aquatic environments, a stress that might well increase over time for the UK given the increasing climate instability within the country. The findings are linked to other information on Be in surface waters for other UK surface waters, including previously unpublished data, to allow a broader perspective for UK riverine environments. Information is provided on Be levels in acidic upland streams in mid Wales (upper River Severn), other eastern UK rivers (collected towards the end of the LOIS initiative) and drainage waters from a disused tin wine in Cornwall (Wheal Jane Mine).