Urban Wastewater Treatment Directive Research Articles

Domestic wastewater treatment by real-scale electrocoagulation process.

In this study, domestic wastewaters originating from a settlement with a population of 17,500 were treated by electrocoagulation process in a real-scale EC plant and the economic applicability of the process was investigated. The removal efficiencies of control parameters in the influent and effluent of the real-scale treatment plant such as suspended solids (SS), biological oxygen demand (BOD), chemical oxygen demand (COD), total nitrogen (TN), total phosphorus (TP) and changes of pH and conductivity parameters were monitored for 12 months. The obtained data were evaluated according to European Urban Wastewater Treatment Directive, Turkish Water Pollution Control Regulation and Turkish Urban Wastewater Treatment Regulation. According to the results obtained, the removal efficiencies of the pollutant parameters were achieved in the range of 72-83% for SS, 67-80% for COD, 69-81% for BOD, 21-47% for TN and 27-46% for TP. Considering the Turkish wastewater discharge regulations, it can be concluded that the discharge standards for SS, COD and BOD parameters were achieved while they were not achieved in certain periods for TN and TP. In addition, the energy consumption and the operating cost of this real-scale plant were determined to be 0.49-0.54 kWh/m3 and 0.24-0.28 EUR/m3, respectively.

Assessment and Comparison of Commonly Used Eutrophication Indexes

Eutrophication is a phenomenon that causes the degradation of the water quality which results in negative impacts on living and non-living environment of the water body. Therefore, monitoring, evaluation and classification of water quality is the utmost importance for policy makers and regional institutions/organizations in order to be able to assess the quality and sustainability of water bodies and take timely and relevant measures for its rehabilitation when and where required. Regional conventions such as the Helsinki Convention, Oslo-Paris Convention, Barcelona Convention – Programme for the Assessment and Control of Marine Pollution in the Mediterranean, Strategic Action Programme and Integrated Coastal Zone Management as well as legislative instruments such as the Water Framework Directive, Marine Strategy Framework Directive, Urban Wastewater Treatment Directive and Nitrate Directive in Europe; the Clean Water Act, Water Quality Act, National Environmental Policy and Coastal Zone Management Act issued by the United State Environmental Protection Agency in the United States, addressed the importance of eutrophication monitoring. The eutrophication indexes have been developed in line with regional requirements by using specific data sets of state variables and parameters, representative of a location. In this study, we reviewed the commonly used eutrophication indexes worldwide within the areas applied, parameters, methods and classification scales and presented trophic level equivalence between the indexes. We expected to provide the researchers with comprehensive approaches related to eutrophication indexes while evaluating the trophic status of a water body.

Forty-year trends in the flux and concentration of phosphorus in British rivers

Given the importance of phosphorus (P) in the eutrophication of natural waters, this study considered the long-term time series of total phosphorus (TP) and total reactive phosphorus (TRP) in British rivers from 1974 to 2012. The approach included not only trend analysis of fluxes and concentrations but also change point analysis. TP and TRP concentrations and fluxes in British rivers have declined since the mid-1980s. Over the last decade of the record the majority of individual sites did show significant downward trends in TP and TRP concentrations but, in 28% of cases for TRP concentration and 14% of cases for TP concentration, the decadal trend was a significant increase. Out of 230 sites, 136 showed a significant step decrease in TRP concentration; no sites showed a significant step increase. The modal year for the step changes for both TRP concentration and flux was 1997. Step changes are likely associated with improvements made at sewage treatment works to comply with the Urban Waste Water Treatment Directive (91/271/EEC). The decrease in TRP concentration due to the step change were in the range of 0.68% and 89% with a geometric mean of 22%, with the rest of the decrease accounted by long-term, persistent downward trend.

Declines in the dissolved organic carbon (DOC) concentration and flux from the UK

Increased concentrations of dissolved organic carbon (DOC) have been reported for many catchments across the northern hemisphere. Hypotheses to explain the increase have varied (eg. increasing air temperature or recovery from acidification) but one test of alternative hypotheses is the trend over the recent decade, with the competing hypotheses predicting: continuing increase; the rate of increase declining with time; and even decrease in concentration. In this study, records of DOC concentration in non-tidal rivers across the UK were examined for the period 2003–2012. The study found that:i)Of the 62 decade-long concentration trends that could be examined, 3 showed a significant increase, 17 experienced no significant change and 42 showed a significant decrease; in 28 of the 42 significant decreases, a significant step change was apparent with step changes being a decrease in concentration in every case.ii)Of the 118 sites where annual flux and concentration records were available from 1974, 28 showed a significant step change down in flux and 52 showed a step down in concentration. The modal year of the step changes was 2000 with no step changes observed before 1982.iii)At the UK national scale, DOC flux peaked in 2005 at 1354 ktonnes C/yr (5.55 tonnes C/km2/yr) but has declined since.The study suggests that there is a disconnection between DOC records from large catchments at their tidal limits and complementary records from headwater catchments, which means that mechanisms believed to be driving increases in DOC concentrations in headwaters will not necessarily be those controlling trends in DOC concentration further downstream. We propose that the changes identified here have been driven by changes in in-stream processing and changes brought about by the Urban Waste Water Treatment Directive. Therefore, signals identified in headwater catchments may bear little relation to those observed in large rivers much further downstream and vice versa.

The control of small and medium sized public wastewater treatment plants in the Veneto region (North Italy): general situation, critical issues and case studies

Abstract Water bodies' quality objectives are defined in accordance with the Urban Wastewater Treatment Directive 91/271/EEC and the Water Framework Directive 2000/60/EC. For regulation and control of small-sized waste-water treatment plants (WWTPs), responsibility is delegated in Italy to Regional Authorities that fix specific regulations (Water Protection Plan WPP included in the River Basin Management Plan RBMP) in collaboration with the District Authorities. Small (<2,000 population equivalent – PE) and medium sized (2,000–10,000 PE) WWTPs in the Veneto Region (North Italy) represent about 10% of the total organic load (Imhoff systems included). This also comprises some industrial discharges. Due to the urban sprawl, plants are spread over the regional territory. In the Veneto Region, data from the official census reveals there are n. 248 plants under 2,000 PE and 135 plants in 2,000–10,000 range while the total number of authorized plants is 488 for a total potentiality of 9,141,572 PE. Data from institutional controls performed by the Veneto Regional Environmental Agency (ARPAV) on WWTPs has been recovered for all the WWTPs with up to 10,000 PE in the provinces of Venice, Treviso and Vicenza (for a total of 306,118 PE and for a total of 164 plants) in the period 2008–2015 and elaborated to assess critical parameters and plants. The general situation, critical issues and case studies have been presented and discussed. Organic load, nutrients and Escherichia coli are the most critical parameters considering the regional WPP.

Characteristics and performance of small and medium wastewater treatment plants in Greece

Wastewater management in Greece is being regulated by the Urban Waste Water Treatment Directive (UWWTD) and as a result many wastewater treatment plants (WWTPs) have been constructed during the last 30 years and are in operation. The present work aims to outline the progress regarding the implementation of the specific environmental policy, present deficiencies and future challenges, while an evaluation of the performance is conducted for small-medium and large WWTPs focusing on the influent and effluent quality characteristics. In Greece the existing level of treatment provided is related to secondary treatment for the removal of organic load, which in most cases is supplemented by nitrogen removal (for more than 85% of the WWTPs) and phosphorus removal. With respect to the characteristics of the raw municipal wastewater these correspond to typical low to medium strength sewage. Compliance to the UWWTD effluent standards for BOD5, COD and SS is achieved in more than 90% of the WWTPs, while in terms of nutrients, 80% of the WWTPs efficiently remove nitrogen and approximately 45% of the WWTPs remove phosphorus.

Low Temperature Domestic Wastewater Treatment in a Microbial Electrolysis Cell with 1 m2 Anodes: Towards System Scale‐Up

AbstractThe potential benefits of applying microbial electrolysis cell (MEC) technology to wastewater treatment are clear and profound. Previous pilot studies have demonstrated a ‘proof of concept' with domestic waste at ambient temperatures, but have not yet treated waste to required discharge standards, and have not reached energy neutrality. In addition, these reactors have been many orders of magnitude smaller than would be needed for full scale wastewater treatment plants. Scale‐up affects many of the parameters that underpin performance; understanding its impact will be vital to further progress. Modifying a previously tested cassette‐style design, we reduced the internal resistance, and increased the module size by a factor of 16, constructing an MEC with six 1 m2 anodes. This created an anodic surface area to volume ratio of 34 m2 m−3. The system was operated at a hydraulic retention time of 5 hours on settled domestic wastewater for 217 days, producing more current than a scaled‐down reactor, which was run in parallel. The large MEC produced 0.8 L of 93% pure H2 d−1 at ambient winter temperatures (11.4 ± 2.5 °C). Chemical oxygen demand (COD) removal averaged 63.5% with an average effluent quality of 124.7 mgCOD L−1, achieving the European Urban Wastewater Treatment Directive (1991) consent.

The challenge of implementing European Union environmental law in the new member states: The Urban Waste Water Treatment Directive in the Czech Republic and Poland

This article examines the problematic implementation of the Urban Waste Water Treatment Directive (UWWTD) in the Czech Republic and Poland from the perspective of the scholarly debate on European Union (EU) and post-accession compliance, focusing on the competing ‘goodness of fit’ and administrative-legal approaches to explaining variations in compliance with EU rules. It finds that administrative shortcomings of various kinds are a major reason for implementation problems in both countries, and that problems have also stemmed from the multilevel nature of the implementation process, which places a heavy administrative and financial burden on municipalities, and requires cooperation between national and local government authorities. In the Czech case, however, the ‘misfit’ between EU standards and contracting and regulatory practices in the Czech water sector has also undermined UWWTD compliance, through its negative impact on the country's ability to access EU funding.

Connecting the shifting currents of aquatic science and policy

Abstract The interface between science and policy is often contentious and characterized by mutual suspicion, yet is critical to both halves of the divide. The application of science to real‐world problems is ultimately one of the greatest markers of scientific achievement, while policy‐makers can reduce the risks of failure by drawing on good evidence. The disproportionately large resource value of inland waters and marine systems together make synergies between science and policy particularly pertinent. Aquatic science has shaped major policy or regulatory legislation, with examples such as the US Clean Water Act (1972) and EU Water Framework Directive (2000/60/EC) deeply rooted in evidence. Modern policy examples are also emerging that can respond to the need for resilience to global change, the protection of natural capital and the sustainable management of ecosystem services. However, practical applications so far remain rudimentary. There have been extensive uses of aquatic conservation science to evaluate the outcomes from past policy implementation. Examples are the role of the EU Large Combustion Plants Directive (88/609/EEC), EU Urban Wastewater Treatment Directive (91/271/EEC) and the US Clean Water Act (1972) in restoring polluted, acidified, and urbanized fresh waters. However, larger‐scale and longer‐term data are required to reveal such policy effects more fully. Evaluations of policies to address recent problems in marine waters affected by climate change, acidification, or anoxia are far less complete. The authors suggest that aquatic scientists can play a pivotal role in identifying gaps or failings in policy or regulatory practice, and we urge our colleagues in aquatic conservation to recognize this role with conviction. A specific policy need is identified – to recognize more fully the importance of connectivity among land, inland waters, and seas to avoid high environmental costs, to capture conservation benefits, and to build resilience in aquatic ecosystems as, arguably, the world's most important environments. Copyright © 2016 John Wiley & Sons, Ltd.

Implementing a composite indicator approach for prioritizing activated sludge-based wastewater treatment plants at large spatial scale

Successful implementation of the European Urban Wastewater Treatment Directive requires a deepened and multidisciplinary knowledge of the wastewater systems. The development of ready-to-use tools for decision makers is, in this sense, a challenge. This paper proposes a methodology to efficiently prioritize wastewater treatment plants (WWTPs) on the basis of the relative environmental, social and public health impacts, taking into account the territorial context issues. The proposed methodology has led to the implementation of a composite indicator. The several choices made for its development, from the definition of framework to the final outcomes, have been evaluated in depth and are supported through methodological and statistical techniques. The potential use of the composite indicator with the inherent advantages and limitations are discussed in order to provide a ready-to-use tool for final users for WWTPs prioritization. Moreover, a concise methodology for composite index implementation is described.

Sewage sludge management in Europe: a critical analysis of data quality

The paper analyses the way numerical data on sewage sludge quantities are recorded, processed and then reported at EU level. The analysed data are the same used by policy makers as official sources. The paper shows the difficulties found during the comparison of EU member states management systems, starting from lack of homogeneity and the fragmentation of the data. Reliable data about sewage sludge production and disposal are indispensable to make a critical analysis and also to realise adjustments and changes to the existing management models as well as in the implementation of European policies, such as the Sewage Sludge Directive or the Urban Wastewater Treatment Directive. Moreover, starting from a critical analysis of EU data, the paper shows how sewage sludge management is dealt by EU countries. Finally, the paper suggests to policy makers some implementation for the data management system in order to reach a higher data reliability.

Sewage Sludge-To-Energy Management In Eastern Europe: A Polish Perspective

Abstract The Sewage Sludge Directive 86/278/EEC was adopted about 30 years ago with a view to encourage sewage sludge reuse in agriculture and to regulate its use. Meanwhile, some EU Member States have adopted stricter standards and management practices than those specified in the Directive. In particular, the majority of Member States has introduced more stringent standards for sludge quality, including stricter limits for most potentially toxic elements, organic contaminants and other elements. In general, untreated sludge is no longer applied and in several Member States it is prohibited. In some cases, stringent standards have resulted in an effective ban on use of sludge in agriculture. Moreover, the implementation of the Urban Wastewater Treatment Directive 91/271/EC should increase EU production of sewage sludge, thus enhancing problems related to sustainable sewage sludge management. Additionally, European legislation prohibits the landfill and water deposits of sewage sludge. The latest trends in the field of sludge management, ie combustion, pyrolysis, gasification and co-combustion, have generated significant scientific interest. This trend is specially strong visible in “new” EU Members countries which have to introduce strong EU Directive in their low system. Here the review the state of knowledge and technology in thermal methods for the utilization of municipal sewage sludge to obtain useful forms of energy such as pyrolysis, gasification, combustion, and co-combustion taking into consideration Poland situation is presented.

An integrated approach for monitoring efficiency and investments of activated sludge-based wastewater treatment plants at large spatial scale

WISE, the Water Information System for Europe, is the web-portal of the European Commission (EU) that disseminates the quality state of the receiving water bodies and the efficiency of the municipal wastewater treatment plants (WWTPs) in order to monitor advances in the application of both the Water Framework Directive (WFD) as well as the Urban Wastewater Treatment Directive (UWWTD). With the intention to develop WISE applications, the aim of the work was to define and apply an integrated approach capable of monitoring the efficiency and investments of activated sludge-based WWTPs located in a large spatial area, providing the following outcomes useful to the decision-makers: (i) the identification of critical facilities and their critical processes by means of a Performance Assessment System (PAS), (ii) the choice of the most suitable upgrading actions, through a scenario analysis. (iii) the assessment of the investment costs to upgrade the critical WWTPs and (iv) the prioritization of the critical facilities by means of a multi-criteria approach which includes the stakeholders involvement, along with the integration of some technical, environmental, economic and health aspects. The implementation of the proposed approach to a high number of municipal WWTPs highlighted how the PAS developed was able to identify critical processes with a particular effectiveness in identifying the critical nutrient removal ones. In addition, a simplified approach that considers the cost related to a basic-configuration and those for the WWTP integration, allowed to link the critical processes identified and the investment costs. Finally, the questionnaire for the acquisition of data such as that provided by the Italian Institute of Statistics, the PAS defined and the database on the costs, if properly adapted, may allow for the extension of the integrated approach on an EU-scale by providing useful information to water utilities as well as institutions.

Trophic state evaluation after urban loads diversion in a eutrophic coastal lagoon (Óbidos Lagoon, Portugal): a modeling approach

Obidos Lagoon is classified as a sensible system according to the eutrophication criteria in the Portuguese Decree-Law 149/2004, which transpose the standards of Urban Waste Water Treatment Directive (Council Directive 91/271/EEC) concerning urban waste water treatment. From September 2005 onwards, the urban loads of five Waste Water Treatment Plant (WWTP) were deviated to a submarine outfall to prevent water degradation and improve the lagoon trophic state (LTS). This paper evaluated the LTS after urban loads diversion, testing the hypothesis behind the management decision. First, the loads reaching the lagoon were determined with the Harp-Nut guidelines and watershed modeling. Then, the water quality in the lagoon was simulated with a hydro-ecological model and compared with measured data. Finally, management scenarios corresponding to nutrient loads reduction were tested to determine hypothesis-driven LTS. Results showed that the loads from pig farms should be diverted instead of the WWTP, to improve the LTS and achieve a “Good/Bad” status. The proposed method stresses the importance of integrated modeling tools in the Water Framework Directive, given their skill in testing various hypothesis, and ultimately ruling out inadequate management decisions before implementation.

Factors affecting the use of waste-stabilization ponds by birds: A case study of conservation implications of a sewage farm in Europe

The progressive loss of natural wetlands globally means that anthropogenic water reservoirs are increasingly important as habitat for wetland bird species. During yearly bird counts (in one-week intervals) on seven waste-stabilization ponds (size range=0.379–4.450ha; total=8.392ha) located on a large sewage farm in a Wrocław city suburb (south-west Poland), I recorded a total of 7776 individuals from 84 bird species. The most numerous bird guild was waterbirds (45.8% of the community), followed by shorebirds (35.7%), passerines (14.9%) and aerial feeders (3.5%). In general, the density (including all bird guilds) and species diversity of birds was positively related to the bed exposure and ‘naturalness’ (artificial≈small ponds with preliminary treatment versus natural≈large ponds after preliminary treatment) of the waste-stabilization ponds. The compulsory European Union (EU) law regulating urban wastewater treatment (The Council Directive 91/271/EEC, Urban Waste Water Treatment Directive) does not permit use of open sewage farms as a method of treatment for domestic and other wastewater. In many new EU member states, the sewage fields are still used, although this method of sewage treatment will function only until 2015, and after that all wastewater must be purified in modern sewage treatment works. It is recommended that areas historically used as sewage farms located on the outskirts of large cities should be converted into protected areas. However, due to the contamination of invertebrates that inhabit and emerge from sewage treatment works, and the potential high risk of detrimental effects on bird species that feed on such prey, empty waste-stabilization ponds should be re-filled with clean natural water sources such as rain and spring water or alternatively with well-treated waste water. The strategy for managing such areas requires a proper water regime and maintenance of the periodically dry bottom, a crucial feeding area for birds.

The EU as an “enforcement patchwork”: the impact of national enforcement for compliance with EU water law in Spain and Britain

AbstractFailures of compliance with European Union (EU) directives have revealed the EU as a political system capable of enacting laws in a wide range of different policy areas, but facing difficulties to ensure their actual implementation. Although the EU relies on national enforcement agencies to ensure compliance with the EU legislation, there is scarce analysis of the differential deterrent effect of national enforcement in EU law compliance. This article examines the enforcement of an EU water directive, the Urban Waste Water Treatment Directive, in Spain and the UK. It focuses on the existing national sanctions for disciplining actors in charge of complying with EU requirements, and on the actual use of punitive sanctions. The analysis shows that a more comprehensive and active disciplinary regime at the national level contributes to explain a higher degree of compliance with EU law. The article calls for a detailed examination of the national administrative and criminal sanction system for a more comprehensive understanding of the incentives and disincentives to comply with EU law at the national state level.

Coping with climate change in Amsterdam – a watercycle perspective

Amsterdam has the ambition to develop as a competitive and sustainable European metropolis. Water and Amsterdam are closely related, and water and climate change are closely related. Therefore, to be sustainable and economically strong, it is necessary for Amsterdam to anticipate the changes in climate that will take place in the Netherlands during the coming decades. Waternet, the watercycle company of Amsterdam and surroundings, has built a response strategy focusing on water management to contribute to the aim of making Amsterdam ‘waterproof’ for the next decades. This response strategy has two building blocks: adaptation and mitigation. With respect to adaptation the focus is on safety against flooding, discharge of rainwater without nuisance for the public, ecological healthy water in compliance with the European Water Framework Directive, a reliable drinking water supply in compliance with the Dutch Drinking Water Regulations and the European Drinking Water Directive, and an efficient and effective wastewater treatment in compliance with the European Urban Wastewater Treatment Directive. With respect to mitigation the focus is on energy recovery from the watercycle and nutrient recovery from wastewater. The strategy is carried out in close cooperation with partners on a regional level and a national level.

Reducing Microbial Pollution in European Coastal Waters: The Challenges of a New Era

Copyright: © 2013 Campos CJA. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Over the last couple of decades, substantial investment has been made in many European countries to improve point-source discharges from sewerage plant and infrastructure [1]. European Union environmental legislation has been the main driver for these improvements, namely the Urban Wastewater Treatment Directive (UWWTD), Bathing Waters Directive (BWD) and Shellfish Waters Directive (SWD). Perhaps, the most thoroughly documented example of the benefits of improved sewage treatment is the increase in the number of coastal and inland bathing waters that consistently achieve compliance with the guideline bacteriological standards of the BWD [2]. Despite this progress, it is now evident that microbial pollutants from diffuse water pollution from agricultural (DWPA), and urban areas contribute a larger proportion of bacterial contaminants delivered to coastal waters than previously thought, and are causing problems for bathing and shellfish waters compliance. Although the impact of DWPA has long been recognised, improvements have been slow and difficult because of the complexity associated with the multiple pollutant transport pathways that are characteristic of this type of pollution. An example of this is the England Catchment Sensitive Farming Initiative, the most comprehensive programme of work carried out to date to identify and reduce DWPA in England. Under the programme, advice has been given to thousands of farmers in 50 catchments covering 40% of the nation’s agricultural land. Despite some good examples of partnership working at local level, a programme evaluation report by the National Audit Office concluded that work to date has not proved value for money because important information gaps still exist on the causes of diffuse pollution, and there has been little progress in persuading those causing most diffuse pollution to acknowledge their responsibility [3]. A significant impediment to the effectiveness of the UWWTD in contributing to reduce sewage pollution relates to the fact that this legislation applies to urban agglomerations of 2,000 people or more, and thus limited scope exists to minimise public health risks in rural areas. Looking ahead, major investment will be needed to maintain sewerage infrastructures compatible with future demographic and land use changes [4].

Development of Estonian nutrient discharge standards for wastewater treatment plants

In order to comply with the Urban Wastewater Treatment Directive's, Water Framework Directive's, Helsinki Commission and Estonian National Wastewater Treatment requirements to reveal the wastewater pressures and impacts on the receiving water, the aim of this work was to develop optimal Estonian Nutrient Discharge Standards for wastewater treatment plants. Wastewater treatment plants treatment efficiency, total pollution load coming from different size of treatment plants and feasibility for stricter treatment requirements and accompanying socio- economic impacts are evaluated with consideration of environmental benefits, brought by the investment. Limit values for small-scale (below 2000 population equivalent) treatment plants were proposed.

GIS-based models for water quantity and quality assessment in the Júcar River Basin, Spain, including climate change effects

This paper describes two different GIS models – one stationary (GeoImpress) and the other non-stationary (Patrical) – that assess water quantity and quality in the Júcar River Basin District, a large river basin district (43,000km2) located in Spain. It aims to analyze the status of surface water (SW) and groundwater (GW) bodies in relation to the European Water Framework Directive (WFD) and to support measures to achieve the WFD objectives.The non-stationary model is used for quantitative analysis of water resources, including long-term water resource assessment; estimation of available GW resources; and evaluation of climate change impact on water resources. The main results obtained are the following: recent water resources have been reduced by approximately 18% compared to the reference period 1961–1990; the GW environmental volume required to accomplish the WFD objectives is approximately 30% of the GW annual resources; and the climate change impact on water resources for the short-term (2010–2040), based on a dynamic downscaling A1B scenario, implies a reduction in water resources by approximately 19% compared to 1990–2000 and a reduction of approximately 40–50% for the long-term (2070–2100), based on dynamic downscaling A2 and B2 scenarios. The model also assesses the impact of various fertilizer application scenarios on the status of future GW quality (nitrate) and if these future statuses will meet the WFD requirements. The stationary model generates data on the actual and future chemical status of SW bodies in the river basin according to the modeled scenarios and reflects the implementation of different types of measures to accomplish the Urban Waste Water Treatment Directive and the WFD. Finally, the selection and prioritization of additional measures to accomplish the WFD are based on cost-effectiveness analysis.