High-frequency water quality monitoring in an urban catchment: hydrochemical dynamics, primary production and implications for the Water Framework Directive

This paper describes the hydrochemistry of a lowland, urbanised river-system, The Cut in England, using in situ sub-daily sampling. The Cut receives effluent discharges from four major sewage treatment works serving around 190,000 people. These discharges consist largely of treated water, originally abstracted from the River Thames and returned via the water supply network, substantially increasing the natural flow. The hourly water quality data were supplemented by weekly manual sampling with laboratory analysis to check the hourly data and measure further determinands. Mean phosphorus and nitrate concentrations were very high, breaching standards set by EU legislation. Though 56% of the catchment area is agricultural, the hydrochemical dynamics were significantly impacted by effluent discharges which accounted for approximately 50% of the annual P catchment input loads and, on average, 59% of river flow at the monitoring point. Diurnal dissolved oxygen data demonstrated high in-stream productivity. From a comparison of high frequency and conventional monitoring data, it is inferred that much of the primary production was dominated by benthic algae, largely diatoms. Despite the high productivity and nutrient concentrations, the river water did not become anoxic and major phytoplankton blooms were not observed. The strong diurnal and annual variation observed showed that assessments of water quality made under the Water Framework Directive (WFD) are sensitive to the time and season of sampling. It is recommended that specific sampling time windows be specified for each determinand, and that WFD targets should be applied in combination to help identify periods of greatest ecological risk. This article is protected by copyright. All rights reserved

The water quality of the River Enborne, UK: observations from high-frequency Monitoring in a rural, lowland river system

This paper reports the results of a 2-year study of water quality in the River Enborne, a rural river in lowland England. Concentrations of nitrogen and phosphorus species and other chemical determinands were monitored both at high-frequency (hourly), using automated in situ instrumentation, and by manual weekly sampling and laboratory analysis. The catchment land use is largely agricultural, with a population density of 123 persons km−2. The river water is largely derived from calcareous groundwater, and there are high nitrogen and phosphorus concentrations. Agricultural fertiliser is the dominant source of annual loads of both nitrogen and phosphorus. However, the data show that sewage effluent discharges have a disproportionate effect on the river nitrogen and phosphorus dynamics. At least 38% of the catchment population use septic tank systems, but the effects are hard to quantify as only 6% are officially registered, and the characteristics of the others are unknown. Only 4% of the phosphorus input and 9% of the nitrogen input is exported from the catchment by the river, highlighting the importance of catchment process understanding in predicting nutrient concentrations. High-frequency monitoring will be a key to developing this vital process understanding

Weekly water quality monitoring data for the River Thames (UK) and its major tributaries (2009–2013): the Thames Initiative research platform

The River Thames and 15 of its major tributaries have been monitored at weekly intervals since March 2009. Monitored determinands include major nutrient fractions, anions, cations, metals, pH, alkalinity, and chlorophyll a and are linked to mean daily river flows at each site. This catchment-wide biogeochemical monitoring platform captures changes in the water quality of the Thames basin during a period of rapid change, related to increasing pressures (due to a rapidly growing human population, increasing water demand and climate change) and improvements in sewage treatment processes and agricultural practices. The platform provides the research community with a valuable data and modelling resource for furthering our understanding of pollution sources and dynamics, as well as interactions between water quality and aquatic ecology. Combining Thames Initiative data with previous (non-continuous) monitoring data sets from many common study sites, dating back to 1997, has shown that there have been major reductions in phosphorus concentrations at most sites, occurring at low river flow, and these are principally due to reduced loadings from sewage treatment works (STWs). This ongoing monitoring programme will provide the vital underpinning environmental data required to best manage this vital drinking water resource, which is key for the sustainability of the city of London and the wider UK economy. The Thames Initiative data set is freely available from the Centre for Ecology and Hydrology’s (CEH)Environmental Information Data Centre at https://doi.org/10.5285/e4c300b1-8bc3-4df2-b23a-e72e67eef2fd

RA-MAP, molecular immunological landscapes in early rheumatoid arthritis and healthy vaccine recipients

Rheumatoid arthritis (RA) is a chronic inflammatory disorder with poorly defined aetiology characterised by synovial inflammation with variable disease severity and drug responsiveness. To investigate the peripheral blood immune cell landscape of early, drug naive RA, we performed comprehensive clinical and molecular profiling of 267 RA patients and 52 healthy vaccine recipients for up to 18 months to establish a high quality sample biobank including plasma, serum, peripheral blood cells, urine, genomic DNA, RNA from whole blood, lymphocyte and monocyte subsets. We have performed extensive multi-omic immune phenotyping, including genomic, metabolomic, proteomic, transcriptomic and autoantibody profiling. We anticipate that these detailed clinical and molecular data will serve as a fundamental resource offering insights into immune-mediated disease pathogenesis, progression and therapeutic response, ultimately contributing to the development and application of targeted therapies for RA.</p

The sources, fate and dynamics of abandoned metal mine water pollutants : a catchment scale investigation of the River West Allen, Northumberland, UK

The implementation in 2003 of the EU Water Framework Directive (2000/60IEC) in England and Wales necessitates addressing water quality issues at the river catchment scale, In the first instance, the overall aim of the Directive is to achieve 'good ecological and chemical status' in all surface and ground water bodies by 2015. Principally due to the presence of elevated metals concentrations, abandoned mine water pollution has been identified by the Environment Agency (England & Wales) as a potentially major impediment to meeting this aim. Particular uncertainty surrounds the importance of diffuse sources of pollution from abandoned mines, the sources and quantification of which have been poorly studied to date. The overall aim of this study was therefore to investigate the importance of diffuse sources of ,,- metals pollution associated with a former-mining district. Within this overall aim, primary objectives included an assessment of the role of diffuse sources under varying hydrological conditions, and an investigation of the potential significance of riverbed sediment as a source and sink o~ metal pollutants. The study site, the River West Allen catchment, Northumberland, forms part of the Alston Block in the north Pennine orefield, the mineral veins of which are largely hosted in Carboniferous Limestone strata. The area was principally worked for zinc (and lead) for over 300 years. As a result, the river is now impacted by three distinct point discharges from these now long abandoned lead-zinc mines. Preliminary reconnaissance surveys illustrated that the pollution arising frpm these drainage adits primarily influences the river's total zinc concentrations, which heavily exceed European statutory environmental quality standards (EQS) throughout much of the catchment. Thus, the sources, fate and dynamics of zinc was the principal focus ofthe work. In this study, synchronous monitoring of aqueous hydrochemistry, flow measurements, and river bed sediment geochemistry, has been -routinely carried out under varying flow conditions for over a year. This has enabled the calculation of the contaminant metal loads at point mine water discharges and selected river locations, under differing hydrological conditions, thus establishing the overall impact of point mine waters within the catchment, and allowing the derivation of contributions from diffuse mine water pollution to the instream totals. In addition, sampling and analysis of river bed sediments (including sequential extraction procedures) has allowed an assessment of the potential importance of such materials as a contributor to diffuse metals pollution. The results of the investigation show that during low flow conditions point source mine water pollution contributes significantly to zinc loadings in the river. In fac~ the total zinc loading . - - ~ - of pojnt sources far exceeds that of the zinc loading in the river downstream of these discharges in low flow conditions (by up to 440%), suggesting considerable attenuation of zinc within the river channel. At all sample sites in the river EQS values are exceeded by up to a factor of 37. Under higher flows instream zinc concentrations exceed EQS values by up to a factor of 57. Point source contributions to total instream zinc loading become far less significant, falling to as little as just 10%. Thus diffuse sources of zinc pollution (i.e. those unaccounted for in the zinc mass balance calculated from point source and instream loadings) account for up to 90% of the instream zinc load, highlighting the dynamic importance of diffuse inputs. Possible diffuse sources include 1) sediment resuspension, due to scouring of metal contaminated river-bed sediments, .q.fld possible subsequent metal remobilisation, 2) direct groundwater input via the hyporheic zone and 3) surface run-off from mine spoil. Of these diffuse inputs the resuspension and possible remobilisation of heavily contaminated sediment has been .investigated in detail here, and appears to be an important potential source of increases in the instream zinc loading during high flow events. The instream concentration and loading of total suspended sediment increases approximately 30-fold and 2,200-fold, respectively, from low to high flow, suggesting sediment resuspension is a key process in releasing zinc into the water column. Zinc concentrations within river-bed sediments typically ~ange from 6,000 - 75,000 mg/kg. These values far exceed interim threshold concentration limits (currently adopted by the Environment Agency) by up to a factor of 600. The majority of this zinc is deemed 'potentially available', as approximately 50% of the total zinc concentration IS associated with carbonates and hydrous ferric oxides. Therefore, changes within pH or redox conditions within the water column may have the potential to remobilise particulate zinc. This work emphasises the potential importance of diffuse sources of mine water pollution in river catchments in former mining districts. In the River West Allen the proportional significance of such point and diffuse sources to total instream zinc loading differs under varying hydrological conditions, and the findings have implications for the management of such pollution issues more widely. For example, it raises questions as to whether treatment of point mine water sources alone will result in measurable environmental benefits in terms of meeting the objectives of the Water Framework Directive. In the River West Allen catchment, while remediation of the point sources of mining pollution would lead to improvements in low flow water quality, the legacy of mining pollution in sedimentassociated metals, and possibly other sources of diffuse metals contamination, may continue to provide an ongoing source of diffuse metal pollution at higher flows.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Salt dissolution dynamics on surface mine spoils

Poor quality water resulting from interaction of surface run-off with saline mine spoil and soils can cause significant problems for water reuse on mine sites. Not only can this saline water lead to machine corrosion and increased maintenance costs, but may cause detrimental effects on the environment. Determining thegeochemistry of mine spoil, and the likelihood of salt dissolution during rainfall events, may aid in more effective mine site management of water. Spoil samples were taken from three areas of the German Creek mine site, situated in the Bowen Basin coalfield, Queensland. Samples from two undisturbed areas on the lease were also collected for comparison. Analyses were performed using a variety of laboratory techniques: leaching tests, effective cation exchange capacity determination, X-ray diffraction, clay quantification, and total organic content determination. Results show that dissolution of surface (top 2 cm) salt minerals from spoil areas is an important contributor to surface run-off salinity during rainfall events. Equally, ion exchange with clay minerals appears to be a significant source of elevated ion concentrations in run-off waters. Findings from the undisturbed areas show undetectable quantities of salt mineral species, resulting in waters with low ion concentrations. More generally, monovalent cations (sodium, and to a lesser extent potassium) appear to be derived from dissolution of salt precipitated whereas divalent cations (calcium, magnesium) are more likely to be sourced from exchange reactions with clay minerals. Incorporating knowledge about the mechanism of cation mobilisation from spoil with the spatial distribution of spoil properties and understanding of the dynamics of water quality variations on the site will aid in development of integrated water quantity and quality management strategies

Weekly water quality data from the River Thames and its major tributaries (2009-2013) [CEH Thames Initiative]

This data set comprises of weekly water quality monitoring data of seven sites along the River Thames, UK, and fifteen of its major tributaries from February 2009 to February 2013. Parameters measured were phosphorus and nitrogen species, dissolved reactive silicon, water temperature, pH, Gran alkalinity, suspended solids, chlorophyll and major dissolved anions (fluoride, chloride, bromide, sulphate) and cations (sodium, potassium, calcium, magnesium, boron). Dissolved and total iron, manganese, zinc, copper concentrations have also been produced from August 2010 to February 2013. The accompanying daily river flow data are also supplied. Samples were taken as part of the Centre for Ecology & Hydrology’s Thames Initiative monitoring programme

Exploring controls on the fate of PVP-capped silver nanoparticles in primary wastewater treatment

Small-angle neutron scattering has been used to examine the settling behaviour of partially-passivated silver nanoparticles (AgNP), capped with a polyvinylpyrolidone (PVP) stabiliser, in water and domestic wastewater, in a primary clarification ‘microcosm’ as a function of time. The impact of two flocculants routinely used in the wastewater treatment process has also been studied. The settling velocity is found to be time-dependent, but always exceeds 100 mm h−1 during the first hour at the point of input. Particle removal by settling is almost three times greater in wastewater than it is in pure water. The results are rationalised in terms of a generic, but synergistic, interaction between non-ionic capping agents and anionic components of wastewater, and we show how this may afford an explanation for some of the diversity of behaviour previously reported in studies of several different NPs in wastewater treatment. We conclude that AgNPs entering primary clarification with non-ionic surface coatings, whether present by design or environmental transformation, pose no threat to the viability of the biofilms in secondary wastewater treatment