The present study analyses the environmental footprint of the Braunschweig wastewater scheme using the methodology of Life Cycle Assessment. All relevant processes of wastewater treatment and disposal are modelled in a substance flow model based on available full-scale data (year 2010) complemented by literature data to calculate aggregated emissions and resource demand of the system. Products of the system (i.e. electricity from biogas combustion, nutrients, and irrigation water) are accounted with credits for the respective substituted products. Beside the status quo of the Braunschweig system in 2010, a set of optimisation scenarios are assessed in their effects on the environmental footprint which target an enhanced recovery of energy and nutrients. The scenarios include the addition of different co-substrates, thermal hydrolysis of sludge in various configurations, nutrient recovery for nitrogen and phosphorus, and utilization of excess heat via an Organic Rankine Cycle (ORC). The energetic balance of the system is comparatively good, as 79% of the cumulative energy demand can be offset by secondary products, mainly biogas (58%) and fertilizer substitution (14%). The optimisation of nutrient and especially water management offers considerable potential for improving the energy balance, the latter due to the high demand of electricity for pumping the water to the fields. The net carbon footprint of the system amounts to 10 kg CO2-eq/(PECOD*a) and is mainly caused by energy-related processes, augmented by direct emissions of N2O and CH4 in the activated sludge process. Nutrient emissions in surface waters are relatively low (29 g P and 80 g N/(PECOD*a)) due to the transfer of nutrients to agriculture and the polishing effect of the infiltration fields. While effects on human toxicity are small after normalisation to German conditions, Cu and Zn emissions to aquatic and terrestrial ecosystems lead to a substantial impact in ecotoxicity (organic substances not accounted). Normalisation of the environmental footprint reveals the primary function of the wastewater treatment plant, i.e. the protection of surface waters from inorganic and organic pollutants and excessive nutrient input. Whereas the quantitative contribution of the system is high for eutrophication and ecotoxicity, energy consumption and correlated indicators such as carbon footprint, acidification and human toxicity have only a minor share to the total environmental impacts per inhabitants in Germany. Consequently, the optimisation of the latter environmental impacts should only be pursued if the primary function of the sewage treatment and related impacts on surface waters are not compromised by these measures. In scenario analysis, both the addition of co-substrates and the thermal hydrolysis of sludge for improving the anaerobic degradation into biogas have a substantial positive effect on the energy balance and carbon footprint without impairing other environmental impacts. Based on the results of the pilot trials in CoDiGreen, the current energy demand can be reduced up to 80% by a combination of adding ensiled grass into the digestor and hydrolysis of excess sludge (potentials have to be verified in full-scale trials). A twostep digestion process with intermediate dewatering and hydrolysis (DLD configuration with EXELYS™) seems promising in terms of energy benefits and carbon footprint. The recovery of nitrogen or phosphorus from the sludge liquor of dewatering does not result in major benefits in the environmental profile, whereas the implementation of an ORC process for energy recovery from excess heat can be fully recommended from an environmental point of view.

The EU-funded R&D project DEMEAU addresses the fate of emerging pollutants in water and waste water treatment, e.g. Managed Aquifer Recharge (MAR). For MAR the objectives are to mobilize existing experience from different European study sites and to develop a systematic approach for the authorization of new recharge schemes in compliance with the European water and groundwater directives. The activities will cover the issue of infiltrating and injecting treated wastewater as well as developing guidance on optimum design and operation of infiltration facilities. In order to demonstrate the effects of typical existing European MAR systems onto groundwater availability and groundwater quality with specific focus on trace organics, a comprehensive relational database (catalogue) on European MAR systems was created to ensure efficient management of available data. By means of the built-in user forms, queries, and reports, database users are enabled to not only view and enter records but also to quickly process the data to extract needed information. In total, 59 different parameters were selected in order to describe about 270 documented MAR sites in 23 countries in Europe. These parameters were then divided up into four main groups (general information, technical data, hydrogeological parameters and monitoring activities) plus references. The database was created using standard software (MS ACCESS) and references were managed by open source software (JABREF). The compiled data on European MAR sites was taken from a variety of different source types, including scientific articles, books, PhD, diploma and master's theses, presentations, technical documents, reports from previous national and EU research projects, personal communication with specialists, operators and water authorities, community and operator websites, newspaper articles, and Google Earth (for geographic coordinates to create overview maps). On the basis of this database a classification system for the MAR sites found in Europe will be developed that can be used for deriving site-specific pre-requisites and design criteria as guidance for the authorization of for new sites.

Das Forschungsprojekt CoDiGreen (2010-2012) zielt auf eine Optimierung der Rückgewinnung von Energie und Nährstoffen in der Abwasserbehandlung in Braunschweig und Berlin. Dafür werden in Pilotversuchen die Auswirkungen einer Zugabe von Co-Substraten (Grassilage, Topinambur) und einer thermischen Druckhydrolyse des Überschussschlamms auf den Biogasertrag der Faulung untersucht. Zusätzlich wird die Co-Vergärung von Grassilage im großtechnischen Maßstab in einem Faulturm des Klärwerks Braunschweig-Steinhof getestet. Neben dem experimentellen Teil wird über eine Ökobilanz der ökologische Fußabdruck des Abwassersystems in Braunschweig und der Schlammbehandlung im Klärwerk Berlin-Wassmannsdorf analysiert, um Optimierungspotential zu erfassen und anhand ausgewählter Szenarien zu bewerten. Abschließend werden vergleichbare Konzepte der landwirtschaftlichen Wiederverwendung von Klarwasser und Schlamm in einer Marktstudie ermittelt und über eine Risikobewertung potentielle Gefahren dieses Systems identifiziert. Die Pilotversuche zeigen, dass sowohl die Zugabe von Co-Substraten als auch die thermische Hydrolyse einen substantiellen Gewinn an Biogasmenge und –qualität (CH4Gehalt) in einer mesophilen Faulung (Verweilzeit: 20d) ermöglichen kann. Die Methanerträge können um 10%, 9% und 13% durch thermische Hydrolyse von Überschussschlamm, Zugabe von Grassilage (+10% FS) und eine Kombination beider Maßnahmen gesteigert werden (sofern der Methanertrag lediglich auf den oTR des zugeführten Schlamms bezogen wird, betrug die Steigerung 10%, 31% und 38%). Eine zweistufige Faulung mit zwischengeschalteter Hydrolyse („DLD“) erbringt +19% CH4. Für anorganische und organische Schadstoffe werden dabei vorgeschriebene Grenzwerte der aktuellen Klärschlammverordnung nicht überschritten. Weiter zeigen Laboranalysen einen positiven Effekt auf die Entwässerbarkeit des Schlamms und den Bedarf an Polymeren. Leider können die vielversprechenden Ergebnisse der Co-Vergärung mit Gras in der Großtechnik nicht bestätigt werden. Für eine großtechnische Realisierung einer Co-Vergärung lässt sich abschätzen, dass für 100.000 EW ca. 30 ha extensiv bewirtschafteter Fläche erforderlich sind, um 10% oTR an Gras in Bezug zum oTR des Rohschlamms zu erzeugen. Leider können die vielversprechenden Ergebnisse der Co-Vergärung mit Gras in der Großtechnik nicht bestätigt werden, in der nur -8% Biogasertrag gemessen werden (+2% wenn der Methanertrag lediglich auf den oTR des zugeführten Schlamms bezogen wird). Obwohl die technische Machbarkeit der Graszugabe gezeigt werden kann, scheinen betriebliche Probleme (Größe der Fasern, hydraulische Durchmischung, niedrige Verweilzeit) die Umsetzung des maximalen Potentials der Graszugabe in der Großtechnik zu verhindern. Die Bewertung der Umweltwirkungen der Systeme in Berlin und Braunschweig zeigt eine hohe Eigenenergieerzeugung in beiden Systemen, so dass dadurch der Treibhauseffekt und andere relevante Umweltwirkungen vermindert werden. Dennoch kann noch Optimierungspotential bei der Energie- und Nährstoffrückgewinnung aufgezeigt werden, zu dessen Erschließung auf der Grundlage einer Szenarienanalyse Empfehlungen formuliert werden. Die Umweltvorteile der Wiederverwendung in Braunschweig zeigen sich vor allem in einer verminderten Emission von Nähr- und Schadstoffen in die Gewässer. Die Normalisierung der Umweltwirkungen unterstreicht die Bedeutung der Primärfunktion der Kläranlage (= Schutz der Oberflächengewässer), die durch Optimierung von Energiebedarf und Treibhausgasemissionen nicht eingeschränkt werden sollte. Die Risikobewertung der Braunschweiger Systems folgt dem HACCP-Konzept und quantifiziert Risiken für die menschliche Gesundheit durch Krankheitserreger und Schwermetalle in der Landwirtschaft und ökologische Risiken durch Schwermetalle. Potentielle Risiken der Wiederverwendung werden auf Grundlage quantitativer Modelle von Umweltverhalten und Exposition identifiziert (Viren, Cadmium für Menschen, Zink für Ökosystem) und sollten durch entsprechende Messprogramme überwacht werden. Schließlich werden basierend auf den Projektergebnissen Empfehlungen zur Optimierung der Energie- und Nährstoffrückgewinnung in der Abwasserbehandlung in Berlin und Braunschweig formuliert, um letztlich die negativen Umweltwirkungen zu minimieren und potentielle Risiken im Betrieb zu vermeiden.

Continuous and quasi-continuous odour monitoring solutions have the potential to provide essential tools to support the whole odour control procedure in sewer networks. Hence, there is a need for continuous measurement and supervision of odour emissions with technical measurement systems. Objective of this investigation is the identification of instruments on the market which have the potential to be applied for odour monitoring from wastewater collection systems or wastewater treatment works. Generally one can distinguish between following methods of odour measurement: (i) Sensory methods: Measurement of odour concentration by olfactometry (evaluation by human noses), (ii) Analytical methods: (ii a) Selected sensors: Measurement of specific single odorants or surrogate parameters (e.g. H2S-measurement) (ii b). Gas chromatography, mass spectrometry, optical sensors: Measurement or quantification of a spectrum of several gas components, (ii c) Multigas-sensor arrays: Measurement of overall odour parameters by means of unspecific, broadband multigas-sensor arrays. Only the mentioned analytical methods provide the possibility of continuous measurements. They however do not all consider the sensory component of odour (perceived effect). Within this report methods (ii b) and (ii c) will be covered. The report provides an introduction to the principle of measurement, briefly discussing examples of sampling methods and data analysis methods and gives lists of collected odour monitoring systems, tabulary providing specifications from literature, manufactures and vendors.

Combined sewer overflows (CSO) impair the quality of urban surface waters around the world. Future change, in particular global warming, is expected to worsen the situation further in many urban areas. To improve the quality of urban surface waters, tools are needed to support decision makers in the assessment of CSO-related impacts and possible mitigation measures. Apart from finding solutions to current problems, it is important that these tools also allow the adaptation of these solutions to future change scenarios to be prepared for likely developments. The present report suggests a model-based planning instrument for the assessment of CSO impacts on receiving surface waters under different sewer management and climate change scenarios. The suggested planning instrument couples a sewer and a surface water model for which boundary conditions can be changed depending on the studied scenario. The simulated CSO impact is then analysed via a coupled impact-assessment tool. The selection of appropriate model approach, assessment guideline and scenarios depend on the local conditions regarding the sewer system, the surface water type and the relevant CSO impact. Accordingly, the report aims at giving a general overview of available models, assessment guidelines, as well as sewer management and change scenarios, which allows setting up a planning instrument for a wide range of local conditions. The present report serves as a step-by-step-manual for setting up an impactbased planning instrument for CSO control: 1. Assessment of possible impacts of CSO, depending on local receiving surface water bodies (chapter 2.1) 2. If this assessment shows the need for a planning instrument, sewer and surface water models should be selected depending on type of impact, type of sewer system and type of surface water body (chapters 2.2 and 2.3). 3. Selected models need to be run, validated and possibly calibrated separately and as coupled tools (chapter 2.4).4. Scenarios are defined consisting of (i) CSO management solutions, depending on impacts of CSO that should be mitigated and sewer system characteristics (chapter 3.2) and (ii) global or local change to be accounted for depending on the local situation (chapter 3.1). The instrument can be used to test sensitivity of CSO impacts to different scenarios or for concrete planning of measures, including cost (chapters 3.3 and 3.4). Use of the manual is exemplified in a case study for Berlin for each of the above steps. Application of the Berlin planning instrument will be demonstrated in Prepared Report D 1.3.2, due in February 2013.

Until around 2004, the term riverbank filtration (RBF) or simply bank filtration (BF, a unified term for river and lake bank / bed filtration) was not commonly used in context to drinking water supply in India. The abundant recharge of traditional dug wells (used for drinking and irrigation) located near surface water bodies (mainly rivers but also some lakes) by very low-turbidity water via natural bank filtration during and after the monsoon has been recognised in India for a very long time. Induced bank filtration has been suggested in the 1970s to address the growing agricultural irrigation demand in the alluvial plains along the Ganga River by inducing recharge from surface water bodies during and after the monsoon (Chaturvedi and Srivastava 1979). Documented evidence till date suggests that induced bank filtration has been used in India for at least 56 years, although even older BF systems may exist. In Nainital, bank filtrate has been abstracted from Nainital Lake since 1956 (Kimothi et al. 2012). BF supplements existing surface and groundwater abstraction for drinking water supply in the cities of Ahmedabad (by the Sabarmati River), Delhi and Mathura (Yamuna) and Nainital (Nainital Lake); on the other hand in Haridwar and Patna (Ganga), and Medinipur and Kharagpur (Kangsabati), BF is used as an alternative to surface water abstraction and to supplement groundwater abstraction (Sandhu et al. 2012). Considering the continuously growing demand for drinking water in sufficient quantities, the emphasis at many BF sites has traditionally been on maximising the volumes of raw water abstracted. Furthermore, the results of a fact-finding study (Ray and Ojha 2005) on the use of BF for drinking water production in India on one hand confirmed that a number of river-side communities have been already using BF for a long time, but that on the other hand only scarce information on the hydrogeological conditions and water quality of these BF sites existed. Holistic investigations on water quality aspects and sustainability (qualitative and quantitative) of these existing BF sites began only after 2004. Water quality investigations conducted at the BF sites of Srinagar by the Alaknanda river (Ronghang et al. 2011), Haridwar and Nainital (Dash et al. 2008, 2010; Sandhu et al. 2011a), Delhi (Sprenger et al. 2008; Lorenzen et al. 2010) and Mathura (Singh et al. 2010; Kumar et al. 2012) and Patna (Sandhu et al. 2011b) showed that the main advantage of using BF in comparison to direct surface water abstraction lies in the removal of pathogens and turbidity. The surface water concentration of trace organic contaminants and their removal at the investigated sites has not been widely investigated, but has shown to be high at sites in Delhi and Mathura (Sprenger et al. 2008; Singh et al. 2010). For conventional treatment, high concentrations of organic contaminants requires high (40–60 mg/L) doses of chlorine prior to flocculation thus creating a greater risk for formation of carcinogenic disinfection by-products, as reported in Mathura (Singh et al. 2010; Kumar et al. 2012). In such situations BF is advantageous as a pre-treatment in order to reduce the necessary doses of chlorine prior to flocculation. Additional advantages of BF may also be seen during the monsoon season principally in the removal of turbidity and pathogens, as well as in the removal of color and dissolved organic carbon (DOC), UV absorbance, turbidity, total and thermotolerant coliform counts, endocrine disruptor compounds and organochlorine pesticides (Dash et al. 2008, 2010; Sandhu et al. 2011a; Thakur et al. 2009a, 2009b; Sprenger et al. 2011; Mutiyar et al. 2011). BF, however, does not present an absolute barrier to other substances of concern (e.g. ammonium) and some inorganic trace elements may even be mobilized. This has been observed in Delhi which has poor surface water quality (Sprenger et al. 2008), at which extensive post-treatment is applied to remove high levels of ammonium. The objective of this deliverable is to provide an overview of known BF schemes in urban areas of India where the abstraction of bank filtrate is intentional. The main water quality issues of concern are highlighted. Related published and unpublished data, as well as new data collected since the commencement of the Saph Pani project in October 2011, is presented for the BF schemes in Haridwar, Nainital, Srinagar (by the Alaknanda river in Uttarakhand), Delhi Mathura and Satpuli (by the Eastern Nayar river in Uttarakhand).

The research project CoDiGreen (2010-2012) targets the optimisation of energy and nutrient recovery in the wastewater treatment schemes of Braunschweig and Berlin. Therefore, pilot experiments are conducted to test the effect of addition of co-substrates (grass silage, topinambur) and the thermal hydrolysis of excess sludge on the biogas yield of anaerobic digestion. In addition, co-digestion of grass silage is also tested in a full-scale digestor of the wastewater treatment plant (WWTP) Braunschweig-Steinhof. Beside the experimental part, the environmental footprint of the wastewater treatment scheme in Braunschweig and the sludge treatment line in WWTP Berlin-Waßmannsdorf is analysed with Life Cycle Assessment (LCA) to identify potentials for optimisation and assess selected technical options in their effects on the environmental profile. Finally, a market review of the concept of agricultural reuse of effluent and sludge in Braunschweig is conducted to get an overview of the market situation, and a risk assessment is initiated to identify potential risks associated with this practice. The results of the pilot experiments show that both the addition of co-substrates and thermal hydrolysis can substantially increase the biogas yield and quality (CH4 content) during mesophilic digestion (HRT = 20d). Methane yields can be increased by 10%, 9% and 13% for thermal hydrolysis of excess sludge, addition of grass silage (+10% TS), and the combination of both (if the methane yield is only related to the VS of the sludge, the increase was 10%, 31% and 38%). A two-step digestion with intermediate hydrolysis (“DLD”) yields +19% CH4. No exceedance of legal requirements for inorganic and organic pollutants can be detected, whereas lab-analysis indicate positive impacts on sludge dewaterability and polymer demand for dewatering. For a full scale realisation of co-digestion it can be estimated that a 100.000 PE WWTP would require approximately 30 ha of extensively cultivated area to add +10% VS of grass substrate. However, the promising results of co-digestion with grass cannot be confirmed in full-scale trials, where only -8% of biogas yield can be measured (+2% if related to the VS of the sludge only). Even though the technical feasibility of grass addition can be shown, operational difficulties (fibre size, hydraulic mixing, low HRT) seem to prevent the realisation of the maximum potential of grass addition in full-scale. The environmental assessment of the systems in Berlin and Braunschweig reveals a high degree of energy production in both systems, lowering associated impacts of carbon footprint and other environmental impacts. However, potentials for optimisation are identified in terms of energy production and nutrient recovery, and recommendations for the future testing of technical options are given based on the scenario analysis within the LCA. Environmental benefits of the reuse approach in Braunschweig are quantified and relate mostly to the lower discharge of nutrients and other pollutants into surface waters. The normalised environmental profile underlines the primary functions of wastewater treatment (= protection of surface waters), which should not be compromised while optimising energy demand and carbon footprint.

Chennai is the largest city in South India located in the eastern coastal plains. Water supply to the Chennai city is met by reservoirs and by groundwater. Most of the groundwater is pumped to the city from the well fields located in the Araniyar and Korttalaiyar River (A-K River) catchment north of Chennai.

The EU-funded R&D project DEMEAU addresses the fate of emerging pollutants in water and waste water treatment, e.g. Managed Aquifer Recharge (MAR). For MAR the objectives are to mobilize existing experience from different European study sites and to develop a systematic approach for the authorization of new recharge schemes in compliance with the European water and groundwater directives. The activities will cover the issue of infiltrating and injecting treated wastewater as well as developing guidance on optimum design and operation of infiltration facilities. In order to demonstrate the effects of typical existing European MAR systems onto groundwater availability and groundwater quality with specific focus on trace organics, a comprehensive relational database (catalogue) on European MAR systems was created to ensure efficient management of available data. By means of the built-in user forms, queries, and reports, database users are enabled to not only view and enter records but also to quickly process the data to extract needed information. In total, 59 different parameters were selected in order to describe about 270 documented MAR sites in 23 countries in Europe. These parameters were then divided up into four main groups (general information, technical data, hydrogeological parameters and monitoring activities) plus references. The database was created using standard software (MS ACCESS) and references were managed by open source software (JABREF). The compiled data on European MAR sites was taken from a variety of different source types, including scientific articles, books, PhD, diploma and master's theses, presentations, technical documents, reports from previous national and EU research projects, personal communication with specialists, operators and water authorities, community and operator websites, newspaper articles, and Google Earth (for geographic coordinates to create overview maps). On the basis of this database a classification system for the MAR sites found in Europe will be developed that can be used for deriving site-specific pre-requisites and design criteria as guidance for the authorization of for new sites.