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Water companies in the United Kingdom are currently facing unprecedented tightening of phosphorus discharge consents, which will only become stricter in the near future. Historically, the most widely applied method of phosphorus removal has been chemical precipitation through the addition of iron or aluminium salts. Although more sustainable options, such as biological processes, are already being implemented at key sites, data shows that chemical removal is likely to remain an integral part of wastewater treatment—whether as the main method in small or problematic works or as a trim for meeting consents below 1 mg/L, not achievable through biological removal alone. All sewage treatment providers in the United Kingdom have developed asset standards (internal design and operation guidelines) for the design and management of chemical precipitation at existing works. However, the approach has not been consistent throughout the sector, with wide variations of criteria, brackets and rules of thumb. This paper collates and compares these approaches, looking at asset standards from most of the water companies in the United Kingdom. The methods stated in these standards have been applied for the sizing of chemical phosphorus removal on four simulated sites, to meet theoretical consents based upon the future discharge requirements set by the Environment Agency under the Water Industry National Environment Programme. Highlights: The study compared the various design guidelines for chemical phosphorus removal from across the water industry in the United Kingdom.This brought to light wide disparities in the design approach.This results in vastly different outputs, potentially oversized equipment and exaggerated forecasts for chemical consumption.Historical site experience, dealing with existing phosphorus permits, has been a key factor for the development of the more streamlined designs by some water companies. [ABSTRACT FROM AUTHOR]

In the United Kingdom, trickling filters remain the most widespread secondary biological treatment process for municipal sewage treatment in terms of number of installations. Ongoing improvement in environmental quality of surface waters requires many of these sites to meet stringent effluent standards. Since publication of the original model for nitrification on mineral media trickling filters by Pearce and Williams in 1999 and the model for nitrification on plastic media filters by Pearce and Edwards in 2010, they have attracted widespread use. Since publication, the models have undergone some refinement and benefitted from an increased application range. Furthermore, recent publications by Pearce and Yang have delivered widely based models for predicting average and seasonal humus tank effluent suspended solids and variability at a resolution of daily 95th percentile performance. This paper presents recent developments of the nitrification models and consolidates the suite of models now available for trickling filter design, evaluation and operation. [ABSTRACT FROM AUTHOR]

The dynamic interactions between dissolved organic matter (DOM) and particulate organic matter (POM) are central in nutrient cycling in freshwater ecosystems. However, the molecular-level mechanisms of such interactions are still poorly defined. Here, we study spatial differences in the chemical (i.e., individual proteinaceous amino acids) and microbial (i.e., 16S rRNA) composition of suspended sediments in the River Chew, UK. We then applied a compound-specific stable isotope probing (SIP) approach to test the potential assimilation of 13C,15N-glutamate (Glu) and 15N-NO3− into proteinaceous biomass by particle-associated microbial communities over a 72-h period. Our results demonstrate that the composition of suspended particles is strongly influenced by the effluent of sewage treatment works. Fluxes and percentages of assimilation of both isotopically labelled substrates into individual proteinaceous amino acids showed contrasting dynamics in processing at each site linked to primary biosynthetic metabolic pathways. Preferential assimilation of the organic molecule glutamate and evidence of its direct assimilation into newly synthesised biomass was obtained. Our approach provides quantitative molecular information on the mechanisms by which low molecular weight DOM is mineralised in the water column compared to an inorganic substrate. This is paramount for better understanding the processing and fate of organic matter in aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Although highway runoff has historically been extensively studied, the increasing complexity of stormwater management means that there are still significant gaps regarding the reduction of soluble metals. The work reported in this paper addresses these challenges by analysing the presence and behaviour of iron, copper and zinc in runoff from junction 24 of the M1 motorway in the UK (peak traffic flow: 30,000 vehicles per hour) and comparing it with other urban sources of metals found in the same catchment (a local brook and sewage treatment works). The sampling site included an interceptor and a treatment lagoon and the event monitoring indicated a trend by which the metals did not change their concentration or particulate soluble proportion immediately, hence showing that pre- and post-storm conditions are important factors when analysing the solubility of metals and their behaviour. The data provided further evidence of the important influence of storm characteristics on metal concentrations in highway runoff, in particular the effects of an antecedent dry weather period (ADWP). In addition, this study also helped us to better understand how the release of sodium the application of de-icer for road maintenance in winter affects the availability of zinc. [ABSTRACT FROM AUTHOR]

Phosphorus enrichment in waterbodies can increase the risk of eutrophication and be detrimental to the health of dependent ecosystems. Phosphorus is a common reason for a waterbody failing to meet the Water Framework Directive 'good' status. The Watton Brook (Norfolk, UK) is required to meet good status by 2027; it currently has an overall 'moderate' status and a 'poor' status for phosphate (as of 2016 classification). Source apportionment modelling predicts treated effluent from water recycling centres is the primary phosphorus source to the Watton Brook, followed by significant agricultural contributions. Considering the agricultural sector input and the cost of upgrading sewage treatment, this study took a stakeholder- and ecosystem services-led approach to explore catchment-based solutions. The feasibility for an integrated catchment approach builds on detailed environmental conceptualisation, phosphorus source apportionment ground-truthing and a review of potential costs and benefits. By combining Farmscoper, SIMCAT-SAGIS InVEST modelling and an ecosystem services assessment, the study targeted solutions to reduce phosphorus loading while delivering multiple benefits. The feasibility and natural capital enhancement focus of a phosphorus balancing scheme in the Watton Brook ensures that the proposed solutions are cost-beneficial for both the wastewater company and its customers while offering wider benefits for the environment and the local community. [ABSTRACT FROM AUTHOR]

This study identifies the basin scale factors and potential remedies to restore the severely polluted Hindon River in India, by comparing with another basin with high population density: the River Thames in the UK. Biochemical oxygen demand (BOD) and dissolved oxygen (DO) in the Thames River are usually around 8 mg/l and 7.5 mg/l respectively, while phosphorus and ammonium range between 0.1–0.6 mg/l and 0.1–0.4 mg/l respectively. The Thames has seen great improvements in water quality over the past decades, due to high levels of sewage treatment and regulation of industrial effluents which have improved water quality conditions. Conversely, the Hindon River suffers from extremely poor water quality and this is mainly attributed to the direct discharge of partially treated or untreated municipal and industrial wastewater into the river. BOD is in the range of 15–60 mg/l and DO is below 5 mg/l. Phosphorus ranges around 2–6 mg/l at most of the monitoring stations and ammonia-nitrogen in the range of 10–40 mg /l in Galeta at Hindon. The analysis of variance also depicts the spatial and temporal variation in water quality in the Hindon River. Besides, non-point sources, pollution from point sources with minimal base flow in the river during dry season, result in low dilution capacity causing high pollutant concentrations which impacts the river ecosystem and fisheries. To restore the Hindon River, resources must be focussed on mainly treating sewage and industrial effluents and by developing appropriate river basin management and regulatory plans. [ABSTRACT FROM AUTHOR]

Treating low C/N domestic sewage is one of the difficult tasks in wastewater treatment. This study investigated the treatment of low C/N domestic sewage under low dissolved oxygen condition via self-built biological contact oxidation reactor with composite packing and polyurethane suspension packing. Meanwhile, MiSeq high-throughput sequencing was performed on the microbial communities on the surface of the packing to analyze the changes in microbial community structure. The results showed that polyurethane suspension packing reactor had better removal efficacy on NH4 +-N, TN and COD than the combined packing reactor, and only the effluent indexes of polyurethane suspension packing reactor could reach the first-class A emission standard of Discharge standard of pollutants for municipal wastewater treatment plant (GB 18918-2002). The removal of biological phosphorus of the single-contact oxidation process was not ideal and could be combined with anaerobic reactor. The richness and diversity of the bacterial community in polyurethane suspension packing reactor was higher than those of composite packing reactor. Polyurethane suspension packing reactor contained relatively richer nitrification-related flora Nitrospira, which provide better growth and reproduction conditions for the denitrification-related flora Betaproteobacteria and Denitratisoma. The large amount of facultative heterotrophic bacteria in Proteobacteria had a significant effect on the removal of organic pollutants. This study provides a theoretical basis for subsequent in-depth research and practical application. [ABSTRACT FROM AUTHOR]

• 240 TWh.year−1 could be generated from food outlets' FOG in the London area. • FOG collected further away from source were richer in water and other contaminants. • FOG demonstrated high biomethane potentials. • Lipids accounted for most of the organic in FOG. • A shift from unsaturated to saturated fats was noticed from source to end point. Several of the waste materials that have a negative impact on the sewer system are produced by fats, oils and greases (FOG) discharged from commercial and domestic kitchens. These materials accumulate at different points in the sewer catchment, from kitchens to pumping stations, sewers and sewage treatment works (STWs), and comprise oily wastewater, floating agglomerates and hard deposits. Despite their detrimental effects, these waste materials have a high calorific content and are an ideal feedstock for energy recovery processes. So far, the overall volume of each type of waste and their physical-chemical properties in relation to their collection point are unknown. However, from a management point of view, knowledge on each feedstock quality and volumes is necessary to develop an economic viable solution for their collection and for energy recovery purposes. In this study, FOG wastes collected from households, food service establishments (FSEs), sewage pumping stations, sewers and STWs, were compared to sewage sludge in terms of organic contents and energy potentials. As expected, FOG recovered at source (households and FSEs) were 'cleaner' and had a higher energy content. Once mixed with wastewater the materials changed in composition and lost some of their energy per unit mass. Our results showed that around 94,730 tonnes.year−1 of these materials could be recovered from the Thames Water Utilities' catchment, one of the most populated in the UK. These materials could produce up to 222 GWh.year−1 as biogas, close to double of what is produced with sewage sludge digestion and around 19% of the company energy needs. Finally, even with over six million households in the catchment, the results showed that most of the FOG waste was produced by FSEs (over 48,000 premises) with an estimated average of 79,810 tonnes.year−1 compared to 14,920 tonnes.year−1 from private households. This is an important outcome as recovery from FSEs will be cheaper and easier if the company decides to implement a collection system for energy recovery. [ABSTRACT FROM AUTHOR]

For water companies, benchmarking their performance relative to other companies can be an effective way to identify the scope for efficiency gains to be made through infrastructure investment and operational improvements. However, a key limitation to benchmarking is the confounding effect of exogenous factors, which may not be factored in to benchmarking methodologies. The purpose of this study was to provide an unbiased comparison of efficiency across a sample of water and sewage companies, accounting for important exogenous factors. Bias-corrected economic and environmental efficiency estimates with explanatory factors were evaluated for a sample of 13 water and sewage companies in the UK and Ireland, using a double-bootstrap data envelopment analysis (DEA) approach. Bias correction for economic and environmental efficiency changed the rankings of nine and eight companies, respectively. On average, companies could reduce economic inputs by 19% and carbon outputs by 16% if they performed at the efficiency frontier. Variables explaining efficiency were: source of water, leakage rate, per capita consumption and population density. Population density showed statistical significance with both economic (p-value 0.002) and environmental (p-value 0.001) efficiency. Consequently, a rurality factor was defined for each company's operational area, which was then regressed against normalised water company performance data. More rural water companies spend more per property (R2 of 0.633), in part reflecting a larger number of smaller sewage treatment works serving rural populations (R2 of 0.823). These findings provide new insight into methods for benchmarking, and factors affecting, water company efficiency, pertinent for both regulators and water companies. • Economic and environmental inputs could reduce by 19.4% and 15.8%. • Bias correction changed the rankings of over 65% of companies. • Population density and surface water % significantly linked to higher efficiencies. • Rurality has relationship with increased spending (R2 of 0.63). • No. of sewage treatment works linked to rurality/spending relationship (R2 of 0.82). [ABSTRACT FROM AUTHOR]

The flux of fluvial carbon from the terrestrial biosphere to the world's oceans is known to be an important component of the global carbon cycle, but within this pathway, the flux and return of carbon to the river network via sewage effluent has not been quantified. In this study, monitoring data from 2000 to 2016 for the dissolved organic carbon (DOC) concentration, biochemical oxygen demand, and chemical oxygen demand of the final effluent of sewage treatment works from across England were examined to assess the amount of DOC contributing to national‐scale fluvial fluxes of carbon. The study shows that the median concentration of DOC in final effluent was 9.4 compared with 4.8 mg C/L for all surface waters for the United Kingdom over the study period and that the DOC in final effluent significantly declined over the study period from 11.0 to 6.4 mg C/L. Rivers receiving sewage effluent showed a significant, on average 19%, increase in DOC concentration downstream of sewage discharges. At the scale of the United Kingdom, the flux of DOC in final effluent was 31 ktonnes C/year with a per capita export of 0.55 kg C/year and compared with an average annual flux of DOC from the United Kingdom of 859 ktonnes C/year, that is, only 3.6% of national‐scale flux. The lability of this DOC was limited, with only 7.4% loss of final effluent DOC concentration over in‐stream residence times of up to 5 days. The direct decline in DOC concentration from sewage treatment works was not large enough on its own to explain the declines observed in DOC concentration in U.K. rivers at their tidal limit. [ABSTRACT FROM AUTHOR]

Abstract Sewage treatment systems are a common feature across the landscape of the United Kingdom, serving an estimated 96% of the population and discharging approximately eleven billion litres of treated wastewater daily. While large treatment facilities are ubiquitous across the landscape, they are not the only method employed in domestic wastewater treatment. This study investigates whether differences in nutrient export (carbon, nitrogen and phosphorus) and organic matter composition (determined by optical indices, SUVA 254 , S 350-400 and E 2 :E 3) from treated effluent could be detected between four of the most common facilities employed in the treatment of wastewater across the UK. Set in the context of the River Wylye, a small headwater catchment, treatment facilities studied included; a septic tank system, small packet treatment works, and two large sewage treatment works, one of which employed phosphorus stripping for phosphorus removal. Inorganic N and P concentrations ranged between 7.51 and 42.4 mg N l−1 and 0.22 and 8.9 mg P l−1 respectively, with DOC concentrations ranging between 1.63 and 11.8 mg C l−1. Optical indices were comparable to those observed in catchments where organic matter is dominated by autochthonous production, suggesting the dominance of low molecular weight material when compared to values observed across temperate aquatic systems. Combining data from both the Environment Agency and Ordinance Survey we estimate that only 15% of domestic properties not connected to mains sewerage in the study catchment have an Environment Agency consent/exemption permit. This calculation suggests that the quantity of small point sources are significantly underestimated, undermining efforts under current legislation to improve stream ecosystem health. Graphical abstract Image 1 Highlights • Variability in effluent discharge from four different wastewater treatment facilities investigated. • Significant differences in C, N and P concentrations and optical indices were observed. • Total numbers of 'off grid' point source discharges estimated. • Only 15% were found to have an Environment Agency permit to discharge. [ABSTRACT FROM AUTHOR]

OPENING UP THE UK WATER AND SEWAGE MARKET TO COMPETITION AIMS TO PROVIDE ECONOMIC AND CUSTOMER BENEFITS. [ABSTRACT FROM AUTHOR]

Environmental pollution has strong links to adverse human health outcomes with risks of pollution through production, use, ineffective wastewater (WW) remediation, and/or leachate from landfill. 'Fit-for-purpose' monitoring approaches are critical for better pollution control and mitigation of harm, with current sample preparation methods for complex environmental matrices typically time-consuming and labour intensive, unsuitable for high-throughput screening. This study has shown that a modified 'Quick Easy Cheap Effective Rugged and Safe' (QuEChERS) sample preparation is a viable alternative for selected environmental matrices required for pollution monitoring (e.g. WW effluent, treated sludge cake and homogenised biota tissue). As a manual approach, reduced extraction times (hours to ∼20 min/sample) with largely reproducible (albeit lower) recoveries of a range of pharmaceuticals and biocidal surfactants have been reported. Its application has shown clear differentiation of matrices via chemometrics, and the measurement of pollutants of interest to the UK WW industry at concentrations significantly above suggested instrument detection limits (IDL) for sludge, indicating insufficient removal and/or bioaccumulation during WW treatment. Furthermore, new pollutant candidates of emerging concern were identified – these included detergents, polymers and pharmaceuticals, with quaternary ammonium compound (QAC) biocides observed at 2.3–70.4 mg/kg, and above levels associated with priority substances for environmental quality regulation (EQSD). Finally, the QuEChERS protocol was adapted to function as a fully automated workflow, further reducing the resource to complete both the preparation and analysis to <40 min. This operated with improved recovery for soil and biota (>62%), and when applied to a largely un-investigated clay matrix, acceptable recovery (88.0–131.1%) and precision (≤10.3% RSD) for the tested pharmaceuticals and biocides was maintained. Therefore, this preliminary study has shown the successful application of a high-throughput QuEChERS protocol across a range of environmental solids for potential deployment in a regulated laboratory. [Display omitted] • Chemometric differentiation of biota, effluent and seasonal sludge using QuEChERS. • Identified detergents, polymers, pharmaceuticals and biocides in sludge. • QAC biocides observed above EQSD levels in sludge. • Rapid, automated analysis of soil and biota with good precision and recovery. • Good accuracy and precision for pharmaceuticals and biocides when applied to clay. [ABSTRACT FROM AUTHOR]

Continuing demands by stakeholders for improved service delivery has caused Infrastructure Client Organisations (ICO) in the UK to embark upon organisational restructuring. It is expected that such restructuring would enhance cost-effectiveness and quality in asset management and service delivery. However, this change, if not properly managed and sustained, could result in the inability of the ICO to achieve these targets. This study outlines the use of systemic thinking and Participatory Action Research (PAR) in driving and managing such change within a UK-based Water and Wastewater ICO (UK WASC). Besides highlighting the context for change in response to policy, austerity and regulatory pressures, this study portrays how the PAR approach can assist in the management of change within ICOs. Furthermore, it provides an insight into the evolution of an external researcher, from novice to expert within the ICO, imbued with the required knowledge to encourage other stakeholders to participate in driving the change management process. Preliminary findings indicate the usefulness of this phased approach toward PAR. This study provides a platform for researchers wishing to engage with ICOs to improve service delivery, identifying the value of engagement, change and systemic thinking. [ABSTRACT FROM AUTHOR]

Numerical odour standards are often used in conjunction with dispersion modelling to assess the acceptability of the odour environment around wastewater treatment works ( WWTWs). However, the odour standards applied are based on very limited research, and there is very little information available regarding how well these standards work in practice. This paper describes the results of a study examining the relationship between odour modelling results and reported complaints around 15 WWTWs in the United Kingdom. Predicted odour concentrations around each of the works were calculated using industry standard odour emission rates. Records of reported odour complaints were obtained from the relevant local authority environmental health department. The study found that odour modelling results did not correlate well with the location of the reported complaints and that in most cases, odour modelling underestimated the area from which complaints would be received. [ABSTRACT FROM AUTHOR]

This study aimed to characterize the carbon isotopic signatures (δ 13C-CH 4) of several methane waste sources, predominantly in the UK, and during field campaigns in the Netherlands and Turkey. CH 4 plumes emitted from waste sources were detected during mobile surveys using a cavity ring-down spectroscopy (CRDS) analyser. Air samples were collected in the plumes for subsequent isotope analysis by gas chromatography isotope ratio mass spectrometry (GC-IRMS) to characterize δ 13C-CH 4. The isotopic signatures were determined through a Keeling plot approach and the bivariate correlated errors and intrinsic scatter (BCES) fitting method. The δ 13C-CH 4 and δ 2H-CH 4 signatures were identified from biogas plants (−54.6 ± 5.6‰, n = 34; −314.4 ± 23‰ n = 3), landfills (−56.8 ± 2.3‰, n = 43; −268.2 ± 2.1‰, n = 2), sewage treatment plants (−51.6 ± 2.2‰, n = 15; −303.9 ± 22‰, n = 6), composting facilities (−54.7 ± 3.9‰, n = 6), a landfill leachate treatment plant (−57.1 ± 1.8‰, n = 2), one water treatment plant (−53.7 ± 0.1‰) and a waste recycling facility (−53.2 ± 0.2‰). The overall signature of 71 waste sources ranged from −64.4 to −44.3‰, with an average of −55.1 ± 4.1‰ (n = 102) for δ 13C, −341 to −267‰, with an average of −300.3 ± 25‰ (n = 11) for δ 2H, which can be distinguished from other source types in the UK such as gas leaks and ruminants. The study also demonstrates that δ 2H-CH 4 signatures, in addition to δ 13C-CH 4 , can aid in better waste source apportionment and increase the granularity of isotope data required to improve regional modelling. • Isotopic 13C signatures from 71 waste sources in UK, NL and TR determined. • Feedstock types have an impact on carbon isotopic signature of generated biogas. • Open and active landfill status has a great impact on carbon isotopic signature. • Sewage treatment is more enriched in 13C than from other waste sources. • Average δ13C isotopic signature of waste sources is −55.1 ± 4.1‰. [ABSTRACT FROM AUTHOR]

Power consumption by the UK water industry has increased as a result of the introduction of new quality standards; the annual (2008/2009) carbon dioxide output was reported at 5·1 Mt. Biogenic output of carbon dioxide for the sector was calculated to be about 2 Mt. The strategies available to the water industry for reducing carbon footprint are increased use of renewable energy, principally anaerobic digestion, using less power and methods for reducing carbon dioxide emissions. This paper reports on work sponsored by UK Water Industry Research to examine methods for capturing and utilising carbon dioxide from wastewater treatment. The review has concluded that bioconversion and biofixation using algae and hydrogenotrophic methanogenesis are the most promising methods for utilising carbon dioxide. These technologies would readily integrate into existing industry flow sheets and both increase biogas production and reduce carbon dioxide emissions. [ABSTRACT FROM AUTHOR]

The author discusses the water high-quality monitoring programs conducted by regulatory agencies such as Environment Agency in England and Wales and Scottish Environmental Protection Agency. He asserts that the program addresses the sewage effluent and environmental consequences and agricultural runoff of pollutants to water courses. He is critical that it was implemented due to increasing population and mobility on water resources, which also adds to the effects of the climate change.

All crops that are eaten raw can present a microbiological risk to consumers. Disease outbreaks in the United Kingdom and United States have illustrated that ready-to-eat crops can be a vehicle for the transmission of gastrointestinal disease. Irrigation water has been implicated as a possible source of microbiological contaminants. Over two-thirds of irrigation water applied to UK salad crops is abstracted from rivers and streams. Many of these are subject to a continuous input of faecal contamination from sewage treatment works as well as intermittent inputs from livestock and sewer overflows. In this paper, we show how geospatial techniques can help to assess the relationships between treated effluent discharges and abstractions and thus provide a new insight into local-scale assessments of irrigation water quality. The extent to which the approach can inform risk assessments and decision-making at the farm scale is demonstrated using a case-study catchment in eastern England. [ABSTRACT FROM AUTHOR]

In this paper we describe some work carried out in the UK into improving the effectiveness of a waste treatment and distribution network. Sludge is the name given to (treated) waste water and sewage. It is collected at small facilities and requires further treatment before it can be disposed of. We develop a linear programming model for the problem of effectively treating and distributing sludge. This model has been implemented in a large UK regional water company, Yorkshire Water. [ABSTRACT FROM AUTHOR]

Abstract: The occurrence of free and conjugated estrogens was examined in a survey of eleven sewage treatment plants (STPs) and their discharge water in the United Kingdom using grab sampling. The STPs included trickling filter with and without tertiary treatment, and activated sludge with tertiary treatment. For three activated sludge plants both influent and effluent samples were compared. For a further 8STPs only the effluent was examined. The estrone-3-sulphate, estradiol-3-sulphate and estriol-3-sulphate concentrations (up to 20ngL−1) were typically 5-fold that of the respective free estrogen concentration in the effluents. This represents a substantial additional ‘potential’ estrogen load arriving in the receiving waters. Estrone-3-glucuronide was found at 9ngL−1, estradiol-3-glucuronide at 7ngL−1, and estriol-3-glucuronide at 32ngL−1 in sewage influent. Except on one occasion, no glucuronide conjugates could be found in the effluent. The results suggest in most cases glucuronide conjugates will be completely transformed in sewage treatment whilst sulphate conjugates will only be partially removed. [ABSTRACT FROM AUTHOR]

Compact vertical flow constructed wetlands (1-2m2/pe, down-flow, single bed, .500mm sand depth) were first installed in the UK in 1998, since when over 40 such beds have been implemented. After ten years of experience, this approach to wastewater treatment is reviewed with respect to operation and maintenance, and water quality improvement. Despite considerable accumulation of organic solids on the surface of some beds after several years' operation, effluent distribution over and permeability of the bed surface, as well as oxygen transfer rates within the bed matrix, have remained satisfactory. Six years of data relating to a 432m2 bed treating combined settled sewage and abattoir effluent have demonstrated consistently high performance. Suspended solids, biochemical oxygen demand and ammonia removal averaged 80, 98 and 91%, respectively, even at a hydraulic loading rate of 340 mm/d. At 12 mm/d, removal was even more thorough. In contrast, accumulation of iron-rich organic solids on the bed's surface, which led to the bed becoming completely flooded, markedly decreased nitrification, although percentage total nitrogen removal was double that of the non-flooded bed. Flow rate analysis through the bed allowed calculation of percentage matrix saturation by effluent during operation, and operational hydraulic residence time (3.83 h), the implications of which are discussed. [ABSTRACT FROM AUTHOR]

Abstract: The regulatory requirements imposed by the Habitats Directive (EU 93/43/EEC) require the Environment Agency for England and Wales (EA) to review consented discharges and determine whether they are compliant with Environmental Quality Standards (EQS). Since the EQS are annual averages, model predictions, and sample comparisons, should be made on an annual average basis. Advection and dispersion of metal contaminants in the Severn Estuary were computed using a coupled 1-D and 2-D hydrodynamic-water quality model. The external inputs of dissolved copper, arsenic, mercury and chromium to the model were from 66 industrial discharges and sewage treatment works and 30 rivers. The annual average predicted concentrations were compared with the annual average dissolved metal concentrations from the 2004 and 2005 monitoring programme, and any discrepancy used to identify the role of additional processes, mainly involving the sediments. This ability to separate anthropogenic inputs from internal estuarine processes contributes to a better understanding of the functioning of the estuary and hence an improved management capability. The paper discusses the approach in designing scenarios and characterising uncertainty, when decision-making in the regulatory context. [Copyright &y& Elsevier]

Abstract: The changing patterns of riverine boron concentration are examined for the Thames catchment in southern/southeastern England using data from 1997 to 2007. Boron concentrations are related to an independent marker for sewage effluent, sodium. The results show that boron concentrations in the main river channels have declined with time especially under baseflow conditions when sewage effluent dilution potential is at its lowest. While boron concentrations have reduced, especially under low-flow conditions, this does not fully translate to a corresponding reduction in boron flux and it seems that the “within-catchment” supplies of boron to the river are contaminated by urban sources. The estimated boron reduction in the effluent input to the river based on the changes in river chemistry is typically around 60% and this figure matches with an initial survey of more limited data for the industrial north of England. Data for effluent concentrations at eight sewage treatment works within the Kennet also indicate substantial reductions in boron concentrations: 80% reduction occurred between 2001 and 2008. For the more contaminated rivers there are issues of localised rather than catchment-wide sources and uncertainties over the extent and nature of water/boron stores. Atmospheric sources average around 32 to 61% for the cleaner and 4 to 14% for the more polluted parts. The substantial decreases in the boron concentrations correspond extremely well with the timing and extent of European wide trends for reductions in the industrial and domestic usage of boron-bearing compounds. It clearly indicates that such reductions have translated into lower average and peak concentrations of boron in the river although the full extent of these reductions has probably not yet occurred due to localised stores that are still to deplete. [Copyright &y& Elsevier]

Abstract: Phosphorus concentrations in the upper River Thames Basin (southeastern England) are described and linked to sewage effluent sources. Weekly surveys between 1997 and 2007 of the Thames and two of its major tributaries, the Thame and the Kennet indicated that phosphorus was mainly in soluble reactive (SRP) form. Baseflow concentrations in the Thames reduced from 1584μg/l in 1998 to 376μg/l in 2006 and from 2655 to 715μg/l for the Thame. Flow response, flux and endmember mixing analysis indicated that these declines resulted from SRP reductions in sewage treatment works (STW) effluent following phosphorus stripping for the major STWs in the region. This was confirmed by comparing our analysis with direct measurements of SRP in the effluents based on Environment Agency data. A within-river loss under baseflow of ~64% (range 56–78%) of the SRP-effluent input was estimated for the Thames, with a near balance for the Thame. SRP concentrations in the Kennet were an order of magnitude lower than the Thames/Thame: non-point sources dominated and were important for all the rivers at high flows. It was concluded that removal of SRP from effluents would be insufficient SRP in the Thames and Thame to meet annual average environmental targets of 50 to 120μg/l. The paper flags the value of combining hydrological/chemical tracing and concentration/flux approaches to data interrogation and the bonus of having actual measurements of the effluent. It highlights the need for fuller assessment of water storage/sediment/biota interactions for phosphorus and for caution in using boron as a long-term tracer for effluent inputs, its concentrations having declined markedly in response to reduced usage in washing powders: the value of using sodium as a tracer for examining SRP changes is shown. [Copyright &y& Elsevier]

Abstract: Platinum-group element (PGE) concentrations in sewage sludge and incinerator ash compared with average PGE concentrations in road dust show a common pattern, characterized by a negative Rh anomaly. This similarity, found at 9 UK incinerators, suggests that there is a universal characteristic PGE pattern produced by common processes of dispersal of Pt, Pd and Rh derived from automobile catalytic converters. Ninety-one sewage sludge and incinerator ash samples from the sewage treatment facilities in Sheffield, Birmingham and 7 other UK cities were analyzed for PGE. The highest concentrations are 602ppb Pt and 710ppb Pd with lower maximum concentrations of 65ppb Rh, 100ppb Ru, 33ppb Ir and 12ppb Os. Ash from incinerated sewage was found to have higher PGE concentrations compared to the original sludge and the PGE ratios are preserved during incineration. Rh is more mobilized and dispersed than the other PGE as it is transported from roads into the drainage system and into sewage. Pt/Pd ratios of 1.0 in road dust and 0.9 in sewage and incinerator ash suggest that Pd is more mobile than Pt during dispersal. PGE abundances in stored incinerator ash of varying ages appear to have been affected by the variation in use of Pt, Pd and Rh in catalytic converters due to variation in their market prices. Concentrations of Os, Ir and Ru in ashes are greater in Sheffield and London than all the other city sites and may be derived from point industrial sources. [Copyright &y& Elsevier]

Abstract: Ferrate(VI) is an oxidant; under acidic conditions, the redox potential of ferrate(VI) salt is the strongest among all oxidants used for water and wastewater treatment. Ferrate(VI) is also a coagulant; during the oxidation process, ferrate(VI) ions are reduced to Fe(III) ions or ferric hydroxide, which simultaneously generates a coagulant in a single dosing and mixing unit process. The superior performance of ferrate(VI) as an oxidant/disinfectant and coagulant in water and wastewater treatment has been extensively studied. However, challenges have existed to the implementation of ferrate(VI) technology in water and wastewater treatment practice due to the instability of the ferrate(VI) solutions and a high preparation cost of a solid ferrate(VI). It would be an ideal approach to generate ferrate(VI) in situ and apply the generated ferrate(VI) directly for wastewater treatment. This paper reports the online preparation and use of ferrate(VI) for sewage treatment at a pilot scale applied in a wastewater treatment plant in the UK. The technology has been demonstrated to be promising in terms of removing suspended solids, phosphate, COD and BOD at a very low dose range, 0.005–0.04mgl−1 as Fe6+ in comparison with a normal coagulant, ferric sulphate at high doses, ranging between 25 and 50mgl−1 as Fe3+. In terms of the similar sewage treatment performance achieved, the required dose with ferrate(VI) was 100 times less than that with ferric sulphate. However, the full operating cost needs further assessment before the ferrate(VI) technology could be implemented in a full scale water or wastewater treatment. [Copyright &y& Elsevier]

The COVID-19 pandemic has put unprecedented pressure on public health resources around the world. From adversity, opportunities have arisen to measure the state and dynamics of human disease at a scale not seen before. In the United Kingdom, the evidence that wastewater could be used to monitor the SARS-CoV-2 virus prompted the development of National wastewater surveillance programmes. The scale and pace of this work has proven to be unique in monitoring of virus dynamics at a national level, demonstrating the importance of wastewater-based epidemiology (WBE) for public health protection. Beyond COVID-19, it can provide additional value for monitoring and informing on a range of biological and chemical markers of human health. A discussion of measurement uncertainty associated with surveillance of wastewater, focusing on lessons-learned from the UK programmes monitoring COVID-19 is presented, showing that sources of uncertainty impacting measurement quality and interpretation of data for public health decision-making, are varied and complex. While some factors remain poorly understood, we present approaches taken by the UK programmes to manage and mitigate the more tractable sources of uncertainty. This work provides a platform to integrate uncertainty management into WBE activities as part of global One Health initiatives beyond the pandemic. [Display omitted] • Wastewater is a relatively unbiased medium transporting multiple markers of human health. • Biological- and chemical-based Wastewater-Based Epidemiology provides flexibility and resilience for public health security. • Measurements of target analytes in wastewater are subject to variability and uncertainty. • Identifying and mitigating uncertainty requires multi-disciplinary collaboration. • UK wastewater monitoring programmes have generated a substantial data resource to derive better understanding of uncertainty. [ABSTRACT FROM AUTHOR]

The article focuses on the incidence of estuarine eutrophication in Great Britain. The eutrophication is being defined as the enrichment of water by nutrients which causes an increasing growth of algae and other forms of plant life that produces an undesirable disturbance in the marine ecosystem. It notes that several estuaries and coastal areas around Great Britain have reported an increase in nitrogen, phosphorus, and concentrations. The main sources of nutrients to estuaries are discharged from seaweeds, river runoff, and atmospheric inputs. It mentions that the European Union's (EU) Urban Waste Water Treatment Directive have reduced the nitrate oxide emission and are expected to decrease further in the next decade.

The article offers information on a lawsuit filed by Shell Green against United Utilities Water PLC which provides services in northwest Great Britain. These include sewers, wastewater treatment plants, sludge treatment plants and a centralised standalone processing plant known as Shell Green. The latter required an integrated pollution prevention and control permit and sought declaratory relief in respect of other sites represented by United Utilities which did not require permits.

A new filtration model has been developed to describe the entire three-stage filtration run. The two-stage assumption is applied for physical description of the rapid gravity filtration process. At the first stage of the filtration, previously deposited particles serve as collectors to improve particle removal efficiency and the detachment of deposited particles does not occur until the specific deposit reaches a certain transient specific deposit where the second stage starts. Particle detachment rate at the second stage is assumed to be a function of relative specific deposit and hydrodynamic conditions within filter media. The proposed filtration model has been applied to fit the data from one water treatment plant of Yorkshire Water (UK). The comparison demonstrates a good agreement between water treatment site data and the simulated results. [ABSTRACT FROM AUTHOR]

This paper is part of the Special Issue of European Environment devoted to the outputs of the EU SRDTOOLS project, which developed and applied a new model of regional sustainable development evaluation. The paper reviews the regional development objectives and strategy of the East Midlands region of the UK, in the context of strong pressure for new housing and limited freshwater supplies and wastewater treatment facilities. The various interactions between these issues are explored using the ‘four-capital model’ and the idea of critical thresholds, which were found to deliver more specific insights than other methodologies into the trade-offs that tend to arise between the various dimensions of sustainable development. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment. [ABSTRACT FROM AUTHOR]

This paper presents a study of UK water industry capital equipment selection, focusing in particular on behaviour in relation to sewerage/combined sewer overflow (CSO) and wastewater-associated investment activities. Valuable new insights into the perspectives of different parties, including water service providers (WSPs), design consultants and construction companies, are provided. Through analysis of over 200 questionnaires, equipment selection is confirmed to be multi-organisational, with different parties dominating different roles. Among the selection criteria, service and quality are found to be valued as parameters worth paying for. Relationships and sustainability considerations are also found to be important, although views on whether sustainability benefits will be paid for are divided. While interparty alignment of views is generally good, there are occasional discrepancies at the individual water region level. It is suggested that optimisation might derive from recognising the significance of intangible components of the supplier offering, and managing relationships to allow these to be capitalised upon. [ABSTRACT FROM AUTHOR]

There are now more than 1,000 constructed wetland systems (CWs) in the UK. The first UK CW database was constructed by Water Research Centre (WRc) and Severn Trent Water Ltd to accompany a book on the design and performance of these systems. In that database, constructed by Gareth Job et al. (1996), only 154 beds were listed, most of which were tertiary sewage treatment sites in Severn Trent Water. The Constructed Wetland Association (CWA) was formed in 2000 as a UK water industry body in response to problems caused by unscrupulous constructors. A group of experienced, reputable designers and constructors formed the CWA to bring together best UK practice in order to counteract this problem. The group contains major water companies, designers, constructors, academics, plant growers and operators. They decided that one of the best ways of countering the problem was to assemble a database of design and performance from well-designed systems. After negotiation the CWA group took over responsibility for the database from WRc. The CWA has produced eight updates of the database which now contains information from more than 900 beds. It contains examples of the different variants of CWs in use in the UK. Most of these sites treat sewage/domestic wastewater but the database also includes examples of systems for the treatment of minewater, sludge, landfill leachate, industrial effluents, surface runoff and road runoff. Particular treatment applications are illustrated by case studies which are summary articles describing design, construction and performance. [ABSTRACT FROM AUTHOR]

Projections of future climate change are plagued with uncertainties, causing difficulties for planners taking decisions on adaptation measures. This paper presents an assessment framework that allows the identification of adaptation strategies that are robust (i.e. insensitive) to climate change uncertainties. The framework is applied to a case study of water resources management in the East of England, more specifically to the Anglian Water Services’ 25 year Water Resource Plan (WRP). The paper presents a local sensitivity analysis (a ‘one-at-a-time’ experiment) of the various elements of the modelling framework (e.g., emissions of greenhouse gases, climate sensitivity and global climate models) in order to determine whether or not a decision to adapt to climate change is sensitive to uncertainty in those elements. Water resources are found to be sensitive to uncertainties in regional climate response (from general circulation models and dynamical downscaling), in climate sensitivity and in climate impacts. Aerosol forcing and greenhouse gas emissions uncertainties are also important, whereas uncertainties from ocean mixing and the carbon cycle are not. Despite these large uncertainties, Anglian Water Services’ WRP remains robust to the climate change uncertainties sampled because of the adaptation options being considered (e.g. extension of water treatment works), because the climate model used for their planning (HadCM3) predicts drier conditions than other models, and because ‘one-at-a-time’ experiments do not sample the combination of different extremes in the uncertainty range of parameters. This research raises the question of how much certainty is required in climate change projections to justify investment in adaptation measures, and whether such certainty can be delivered. [Copyright &y& Elsevier]

Abstract: Estuaries are sinks for organic matter and nutrients entering both from their catchments and also from the adjacent lands and urban areas and in turn they are sources of such materials to the adjacent coast. The present paper quantifies the relative amounts of natural and anthropogenic organic matter and nutrients entering the Humber Estuary, Eastern England, including the allochthonous and autochthonous materials, those from urban and industrial sewage and from the catchment drainage of arable land. These data thus give a budget for the estuary which in turn answers questions fundamental to the management of the estuary. The estimations within the study have been carried out against a background of designating estuaries under the European Union Urban Waste-water Treatment Directive and the EU Nitrates Directive. The assessment has particularly addressed the question, related to the former Directive, of whether the Humber Estuary is eutrophic or likely to become eutrophic unless management measures are taken. Thus the paper indicates the nature and value of control measures such as treatment plant upgrading and the designation of Nitrate Vulnerable Zones. The paper includes the recent national and European discussions on the designation of areas under these Directives. Finally, the study has allowed a quantification of the present organic inputs to the estuary in comparison to those entering prior to large scale land-claim which had removed natural organic-producing wetlands. [Copyright &y& Elsevier]

The responses of epilithic bacterial and algal communities to sewage-treatment-works (STW) effluent were studied in three streams in North Yorkshire, England, using both conventional microbiological techniques and the techniques of molecular genomics. Cod Beck, Thornton Beck and the River Wiske, were visited in May–June 2000 and January 2001 and the epilithic communities on submerged stones were sampled to determine chlorophyll- a, leucine assimilation, bacterial abundance, identity and abundance of microalgae, and epilithon dry and organic weights. Additionally, DNA from the epilithon of stones, collected in March–April and November 2000, was extracted, and samples were amplified using universal primers appropriate, respectively, for bacteria [Muyzer et al., 1993. Applied and Environmental Microbiology 59: 695–700] and microscopic phototrophs [Nübel et al., 1997. Applied and Environmental Microbiology 63: 3327–3332] followed by DGGE (Denaturing Gradient Gel Electrophoresis). Differences in algal community composition and abundance were greater between streams than between sites upstream and downstream of the STW outfalls. DGGE banding profiles of bacterial communities revealed grouping according to stream, and not the formation of communities characteristic of downstream sites; seasonal variation was also evident. Thus the discharge of STW effluent to the streams did not bring about the development of communities that are characteristically associated with organic pollution. Changes in composition and structure of bacterial and micro-algal epilithic communities were detected, but the relatively high quality effluents had only mild effects, not altering the environments sufficiently to override the natural differences between the three streams. [ABSTRACT FROM AUTHOR]

Abstract: Predicted environmental concentrations for five commonly used pharmaceuticals were calculated using data from the UK Department of Health according to risk assessment guidelines proposed by the European Agency for the Evaluation of Medicinal Products. Surface waters from the South–East of England were analysed and results were compared with predicted concentrations and findings from other studies from the UK and Europe. It was found that the efficacy of these predictions varied and was hampered by a shortage of data for many of the drugs. Ibuprofen, paracetamol and salbutamol were detected and quantified in all locations sampled. Ibuprofen was consistently found at the highest concentrations (up to 3μgl−1). Levels up and downstream of two wastewater treatment works were compared in order to investigate the link between sewage discharge and environmental concentrations of pharmaceuticals. Results from one site demonstrated a considerable increase in concentrations of ibuprofen, salbutamol and paracetamol downstream from the treatment works; however, no link was established for a second works. [Copyright &y& Elsevier]

Pharmaceuticals are produced and used in increasingly large volumes every year. With this growth comes concern about the fate and effects of these compounds in the environment. The discovery of pharmaceuticals in the aquatic environment has stimulated research in the last decade. A wide range of pharmaceuticals has been found in fresh and marine waters, and it has recently been shown that even in small quantities, some of these compounds have the potential to cause harm to aquatic life. The primary pathway into the environment is the use and disposal of medicines; although much of the research in the area currently focuses on the removal of pharmaceuticals during sewage treatment processes, disposal via household waste might be a significant pathway requiring further research. To investigate the household disposal of unused and expired pharmaceuticals as a source of pharmaceutical compounds in the environment, we carried out a survey and interviewed members of 400 households, predominantly from southeastern England. We used the information on when and how they disposed of unfinished pharmaceuticals to construct a conceptual model to assess the pathways of human pharmaceuticals into the environment. The model demonstrated that disposal of unused pharmaceuticals, either by household waste or via the sink or toilet, may be a prominent route that requires greater attention. [ABSTRACT FROM AUTHOR]

Surveys of U.K. rivers have shown a high incidence of sexual disruption in populations of wild roach (Rutilus rutilus) living downstream from wastewater treatment works (WwTW), and the degree of intersex (gonads containing both male and female structural characteristics) has been correlated with the concentration of effluent in those rivers. In this study, we investigated feminized responses to two estrogenic WwTWs in roach exposed for periods during life stages of germ cell division (early life and the postspawning period). Roach were exposed as embryos from fertilization up to 300 days posthatch (dph; to include the period of gonadal sex differentiation) or as postspawning adult males, and including fish that had received previous estrogen exposure, for either 60 or 120 days when the annual event of germ cell proliferation occurs. Both effluents induced vitellogenin synthesis in both life stages studied, and the magnitude of the vitellogenic responses paralleled the effluent content of steroid estrogens. Feminization of the reproductive ducts occurred in male fish in a concentration-dependent manner when the exposure occurred during early life, but we found no effects on the reproductive ducts in adult males. Depuration studies (maintenance of fish in clean water after exposure to WwTW effluent) confirmed that the feminization of the reproductive duct was permanent. We found no evidence of ovotestis development in fish that had no previous estrogen exposure for any of the treatments. In wild adult roach that had previously received exposure to estrogen and were intersex, the degree of intersex increased during the study period, but this was not related to the immediate effluent exposure, suggesting a previously determined programming of ovotestis formation. [ABSTRACT FROM AUTHOR]

1. We compared the baseline phosphorus (P) concentrations inferred by diatom-P transfer functions and export coefficient models at 62 lakes in Great Britain to assess whether the techniques produce similar estimates of historical nutrient status. 2. There was a strong linear relationship between the two sets of values over the whole total P (TP) gradient (2–200 μg TP L−1). However, a systematic bias was observed with the diatom model producing the higher values in 46 lakes (of which values differed by more than 10 μg TP L−1 in 21). The export coefficient model gave the higher values in 10 lakes (of which the values differed by more than 10 μg TP L−1 in only 4). 3. The difference between baseline and present-day TP concentrations was calculated to compare the extent of eutrophication inferred by the two sets of model output. There was generally poor agreement between the amounts of change estimated by the two approaches. The discrepancy in both the baseline values and the degree of change inferred by the models was greatest in the shallow and more productive sites. 4. Both approaches were applied to two lakes in the English Lake District where long-term P data exist, to assess how well the models track measured P concentrations since approximately 1850. There was good agreement between the pre-enrichment TP concentrations generated by the models. The diatom model paralleled the steeper rise in maximum soluble reactive P (SRP) more closely than the gradual increase in annual mean TP in both lakes. The export coefficient model produced a closer fit to observed annual mean TP concentrations for both sites, tracking the changes in total external nutrient loading. 5. A combined approach is recommended, with the diatom model employed to reflect the nature and timing of the in-lake response to changes in nutrient loading, and the export coefficient model used to establish the origins and extent of changes in the external load and to assess potential reduction in loading under different management scenarios. 6. However, caution must be exercised when applying these models to shallow lakes where the export coefficient model TP estimate will not include internal P loading from lake sediments and where the diatom TP inferences may over-estimate TP concentrations because of the high abundance of benthic taxa, many of which are poor indicators of trophic state. [ABSTRACT FROM AUTHOR]

The implementation of water demand management strategies, particularly in urban environments, can contribute towards improved sustainability (or at least reduce unsustainability) in the water sector. Greywater treatment, and its subsequent use for toilet flushing, is one of the demand management options offering considerable water-saving potential. The uptake of greywater recycling systems (GRSs), particularly in the UK, is low. One of the reasons for such a low uptake is the perception that GRSs have a high (unsustainable) cost/benefit ratio. This paper presents progress on the development of a whole-life cost (WLC) model, aimed at facilitating decision making for the implementation of GRSs in relation to their economic viability. [ABSTRACT FROM AUTHOR]

Three pilot-scale facultative ponds, located at Esholt wastewater treatment works in Bradford, West Yorkshire, UK were operated in parallel for 53 months, each with different BOD loadings and hydraulic retention times. Measurements of the sludge accumulation were made at 6-monthly intervals commencing at 3 months after start-up. In addition grab sludge samples were collected and analysed for total solids, volatile solids and faecal coliforms. After the first year of operation the sludge accumulation rate was 0.74 m3yr-1 for all three ponds (p=816), independent of BOD loading and HRT; the per capita accumulation rates were within the range 0.08-0.16 m3 person-1 yr-1. Evidence of degradation was found in the sludge from the percentage of volatile solids in the dry solids, but insignificant removal of faecal coliforms. [ABSTRACT FROM AUTHOR]

Grassland in the United Kingdom can accept sewage sludge when, as a result of cropping restrictions, arable land cannot. However, one of the uncertainties associated with the application of sewage sludge to grassland is the potential exposure of the grazing ruminant to sewage sludge particulates adhered to the grass or deposited on the soil surface. The implications of elevated levels of sludge particulates and associated potentially toxic metals (PTMs) are the potential accumulation of PTMs into edible tissues of the grazing animal. Two experiments were performed to investigate the effect of season of application on the adhesion, retention and recontamination of herbage by sewage sludge and PTMs. In each experiment, three treatments were installed, an untreated control, application of sludge in the autumn and application of sludge in the spring. Sewage sludge particulates and PTMs were eluted sequentially 21 days after the application of sludge using water and detergent and the residual (tissue) concentrations were monitored. Total concentrations in each fraction and adhesion indices were calculated. Soil samples taken from the sward treatments after each application showed no elevated concentrations of PTMs or concentrations that approached the maximum concentrations allowed for soils amended with sewage sludge. The amounts of sludge adhered to herbage ranged from 114 to 360 g sludge DM/kg herbage DM. There was evidence of preferential retention of PTMs to herbage. However, during the 21-day no grazing period there was a general decline in concentration of all PTMs. Copper was retained on the herbage for greater periods of time compared to Zn, CD, Pb and Fe (P<0.01). The proportion of Pb recovered from the water phase increased during the 21-day no grazing period in comparison to Cu, Zn and Fe (P<0.001). It is concluded that the concentrations of PTMs adhered and integral to herbage as a result of surface application of sewage sludge are likely to fall to acceptable levels in well-managed permanent grassland. [Copyright &y& Elsevier]