Food production in Europe is dependent on imported phosphorus (P) fertilizers, but P use is inefficient and losses to the environment high. Here, we discuss possible solutions by changes in P management. We argue that not only the use of P fertilizers and P additives in feed could be reduced by fine-tuning fertilization and feeding to actual nutrient requirements, but also P from waste has to be completely recovered and recycled in order to close the P balance of Europe regionally and become less dependent on the availability of P-rock reserves. Finally, climatesmart P management measures are needed, to reduce the expected deterioration of surface water quality resulting from climate-change-induced P loss.

Germany’s municipal sewage treatment plants generate some two million tons of dry sewage sludge annually, with the proportion of thermally treated sewage sludge increasing from 31.5 per cent in 2004 to more than 54 % in 2011. Sludge, which is usually incinerated or used as agricultural fertilizer, contains a whole series of harmful substances that complicate the task of sludge management. But sludge also contains a number of nutrients such as phosphorus, nitrogen and potassium. Hence the goal of sewage sludge management is to remove sludge pollutants while retaining sludge nutrients. Sewage sludge undergoes thermal recycling at facilities such as sewage sludge mono-incineration plants, cement plants and coal fired power plants. Sewage sludge utilization for farming purposes has plateaued of late (2006 to 2011) at around 29 %, an evolution attributable to more stringent quality standards for sewage sludge. However, sewage sludge is set to take on greater importance as a raw material, mainly due to the increased concentrations of phosphorous it contains. This pamphlet discusses the potential offered by sewage sludge and the ways it can be used sustainably. The pamphlet also describes the current status of sewage sludge management in Germany, with particular emphasis on the extent to which sludge use as a fertilizer can be reduced without foregoing phosphorous and other sludge nutrients. Over the next one to two decades, Germany needs to wean itself away from using sewage sludge for farming and at the same time efficiently leveraging the potential for using sewage sludge as a low cost fertilizer.

Im Rahmen des Forschungsprojekts SEMA ist die Prognosequalität eines Alterungsmodells anhand der TV-Inspektionsdaten der Stadt Braunschweig geprüft worden. Die Qualität der Prognose wurde auf der Grundlage einer Probe von 35.826 Inspektionen bewertet. Die Inspektionen wurden mittels eines substanzbasierten Modells klassifiziert. In einem zweiten Schritt wurde das statistische Modell KANEW-Z angewandt, um die Kanalalterung zu simulieren. Der Vergleich der Inspektions- mit den Simulationsergebnissen zeigt, dass das Modell in der Lage ist, die Zustandsverteilung des Systems ziemlich genau wiederzugeben. Die Ergebnisse sind auch ermutigend auf individueller Haltungsebene. Im Allgemeinen zeigt das Alterungsmodell viel bessere Ergebnisse als ein einfaches lineares Alterungsmodell. Schlussfolgernd unterstreichen die Ergebnisse das Interesse und den potentiellen Nutzen der Anwendung von Alterungsmodellen zur Unterstützung von Asset-Management-Strategien.

This paper reports about experiences gathered from five on-line monitoring campaigns in the sewer systems of Berlin (Germany), Graz (Austria), Lyon (France) and Bogota (Colombia) using UV-VIS spectrometers and turbidimeters. The influence of local calibration on the quality of on-line COD measurements of wet weather discharges has been assessed. Results underline the need to establish local calibration functions for both UV-VIS spectrometers and turbidimeters. It is suggested to practitioners to calibrate locally their probes using at least 15-20 samples. However, these samples should be collected over several events and cover most of the natural variability of the measured concentration. For this reason, the use of automatic peristaltic samplers in parallel to on-line monitoring is recommended with short representative sampling campaigns during wet weather discharges. Using reliable calibration functions, COD loads of CSO and storm events can be estimated with a relative uncertainty of approximately 20 %. If no local calibration is established, concentrations and loads are estimated with strong errors questioning the reliability and meaning of the on-line measurement. Similar results have been obtained for TSS measurements.

Several infrastructure studies highlight the ongoing deterioration of critical assets in water and wastewater systems (WERF, 2007). A recent survey among 397 water and wastewater industry participants in the U.S.A. and Canada highlights that aging infrastructure and the management of capital and operational costs are the two main industry issues (Black and Veatch, 2013). From the participants, more than 70% of municipalities and utilities have already implemented condition assessment and inspection programs to assess the condition state of their systems. However, less than 10% are currently using simulation tools to support their asset management strategies. These results underline the strong opportunity for municipalities and utilities to increase the efficiency of their asset management programs by extracting the value of their (already) available data. Several modeling approaches are now available but not commonly used by sewer operators to support strategies (Caradot et al., 2013). Indeed, most of these models still fail to show that they can adequately forecast future conditions (Ana and Bauwens, 2010; Scheidegger et al., 2011). This article presents an assessment of the ability of sewer deterioration models to simulate the condition distribution of sewer networks. The analysis has been done using the extensive CCTV dataset of a German city, Braunschweig.

This article presents an assessment of the quality of prediction of a Markov-based statistical sewer deterioration model using the extensive CCTV dataset of a German city, Braunschweig. Additionally, a sensitivity analysis has been performed in order to assess the influence of input data availability on model performance. Results indicate that models are able to simulate quite accurately the condition distribution of the network with deviations smaller than 1%. Results also indicate that the performance of deterioration models is quite independent of the amount of CCTV data available to calibrate the model. Even when using very few data (˜3%, i.e. 1000 inspections) to calibrate the model, very good model performance can be obtained.This article presents an assessment of the quality of prediction of a Markov-based statistical sewer deterioration model using the extensive CCTV dataset of a German city, Braunschweig. Additionally, a sensitivity analysis has been performed in order to assess the influence of input data availability on model performance. Results indicate that models are able to simulate quite accurately the condition distribution of the network with deviations smaller than 1%. Results also indicate that the performance of deterioration models is quite independent of the amount of CCTV data available to calibrate the model. Even when using very few data (˜3%, i.e. 1000 inspections) to calibrate the model, very good model performance can be obtained.

Whether or not there will be a phosphorus (P) peak within decades, centuries or millennia, (Cordell and White, 2011; Scholz and Wellmer, 2013) one thing is for sure – phosphorus is a limited and, in its function as a nutrient, an essential and irreplaceable resource (Asimov, 1959; Smil, 2000; Filippelli, 2008). The debate on P limitation is often mentioned as motivation to foster activities regarding P recovery and recycling. The ambition of the European Commission (EC) to establish a circular economy in Europe goes far beyond that and is not primarily motivated by limitations of certain raw materials. From the European perspective and in the light of having just one small mine in Finland, the geopolitics and economic vulnerability are issues to be taken seriously. Europe is highly dependent on phosphorus imports (De Ridder et al., 2012) as reflected by the quantities given in figure 1. In contrast to the above mentioned issues, the waste and dissipation of phosphorus that exists in developed countries may lead to a different conclusion. The global resource efficiency for P along the supply chain from mine to fork is only 20% (Schröder et al., 2010). Given the figures of 225 million tons P rock globally mined in 2013 (USGS, 2015) and assuming that 90% of the mined P is used for food production, only 45 million tons of the mined quantity finally ends up in form of food on our tables. So, what can we do to increase the resource efficiency of P? Recently, the implementation of a coherent package of nutrient management strategies and measures to close the European P cycle has been proposed – the 5R strategy (Withers et al., 2015). The five R’s are Realign P inputs, Reduce P losses to waters, Recycle P in bio-resources, Recover P from waste and finally Redefine our food system. So, recovery and recycling can play an important role in improving resource efficiency and sustainable nutrient management. Although, there are various relevant waste streams carrying huge quantities of phosphorus dissolved in liquids or fixed in solids like in manure or organic waste, the focus of P-REX was laid upon P recovery and recycling from wastewater and sewage sludge.

This report provides the reader with an overview of assessment methodologies used within DEMOWARE and the specific features when using QMRA, QCRA, LCA, and WFP approach for the assessment of water reuse systems. For the actual application of LCA and water footprint databases and assessment software is needed. Therefore, three complementing goals shall be achieved: (i) to provide practitioners with the principles, methods and limitations of QMRA, QCRA, LCA and WFP (ii) to provide LCA, WFP, RA practitioners with additional information when using the respective method for the assessment of water reuse systems. For QMRA a summary of guidelines and default values is collected from different guidelines documents (WHO, Australia, US-EPA), which allow a first simplified and thus user friendly risk estimate.