Max Maurer's research while affiliated with Eawag: Das Wasserforschungs-Institut des ETH-Bereichs and other places

Publications (66)

Article
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Increasing urbanization degrades quantity, quality, and the functionality of spatial cohesion of natural areas essential to biodiversity and ecosystem functioning worldwide. The uncontrolled pace of building activity and the erosion of blue (i.e., aquatic) and green (i.e., terrestrial) landscape elements threaten existing habitat ranges and movabil...
Article
Future climatic, demographic, technological, urban and socio-economic challenges call for more flexible and sustainable wastewater infrastructure systems. Exploratory modelling can help to investigate the consequences of these developments on the infrastructure. In order to explore large numbers of adaptation strategies, we need to re-balance the d...
Article
Full-text available
Sanitation in India has received national attention for over a decade, especially with the Swachh Bharat Mission (SBM) making it a political priority. However, due to the lack of appropriate sanitation planning practices, there have been little long-term gains made in urban sanitation beyond the ending of open defaecation. In this paper, we analyse...
Preprint
On-site wastewater treatment plants (OSTs) are widely seen as a stopgap solution, mainly because of a lack of monitoring and the resulting unreliable treatment performance. To address this concern, low maintenance, but inaccurate soft sensors are emerging. However, the impact of this inaccuracy on the treatment performance of entire fleets of OSTs...
Article
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Technical alternatives offering high water efficiency are being developed to complement existing centralized water and wastewater conveyance and treatment systems. Understanding of the negative effects wide‐spread implementation of such alternative systems may have on existing systems is still limited, despite the importance of this inevitable tran...
Article
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Sustainable urban drainage systems (SuDS) help in stormwater management by reducing runoff volume, increasing runoff concentration time and thereby improving the drainage system capacity. This study investigated the potential and cost-effectiveness of SuDS in reducing combined sewer overflows (CSOs). We simulated the performance of four SuDS techni...
Article
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To prioritise sustainable sanitation systems in strategic sanitation planning, indicators such as local appropriateness or resource recovery have to be known at the pre-planning phase. The quantification of resource recovery remains a challenge because existing substance flow models require large amounts of input data and can therefore only be appl...
Article
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To provide access to sustainable sanitation for the entire world population, novel technologies and systems have been developed. These options are often independent of sewers, water, and energy and therefore promise to be more appropriate for fast-growing urban areas. They also allow for resource recovery and and are adaptable to changing environme...
Article
On-site wastewater treatment plants (OST) are usually unattended, so failures often remain undetected and lead to prolonged periods of reduced performance. To stabilize the performance of unattended plants, soft-sensors could expose faults and failures to the operator. In a previous study, we developed soft-sensors and showed that soft-sensors with...
Article
Recent developments in high- and middle-income countries have exhibited a shift from conventional urban water systems to alternative solutions that are more diverse in source separation, decentralization, and modularization. These solutions include non-grid, small-grid, and hybrid systems to address such pressing global challenges as climate change...
Preprint
On-site wastewater treatment plants are usually unattended, so undetected failures often lead to prolonged periods of reduced performance. To stabilize the good performance of unattended plants, soft-sensors could expose faults and failures to the operator. In a previous study, we developed soft-sensors and showed that soft-sensors with data from u...
Article
Decision-making in environmental management requires eliciting preferences of stakeholders and predicting outcomes of decision alternatives. Usually, preferences and predictions are both uncertain. Uncertainty of predictions can be tackled by multi-attribute utility theory, but the uncertainty of preferences remains a challenge. We demonstrate an a...
Article
Sensor maintenance is time-consuming and is a bottleneck for monitoring on-site wastewater treatment systems. Hence, we compare maintained and unmaintained sensors to monitor the biological performance of a small-scale sequencing batch reactor (SBR). The sensor types are ion-selective pH, optical dissolved oxygen (DO), and oxidation-reduction poten...
Article
Contaminants in sewer overflows can contribute to exceedances of environmental quality standards, thus the quantification of contaminants during rainfall events is of relevance. However, monitoring is challenged by i) high spatiotemporal variability of contaminants in events of hard-to-predict durations, and ii) a large number of remote sites, whic...
Article
We present a novel stochastic model for quantifying gross solids (GS) physical disintegration under varying turbulent flow conditions and used a unique experimental setup for model calibration and validation. The stochastic deterioration model predicts faeces size evolution over time. It conceptually entails the two main processes of solid fragment...
Preprint
The identification of appropriate sanitation systems is particularly challenging in developing urban areas where local needs are not met by conventional solutions. While structured decision-making frameworks such as Community-Led Urban Environmental Sanitation (CLUES) can help facilitate this process, they require a set of sanitation system options...
Preprint
Sensor maintenance is time-consuming and is a bottleneck for monitoring on-site wastewater treatment systems. Hence, we compare maintained and unmaintained pH, dissolved oxygen (DO), and oxidation-reduction potential (ORP) sensors to monitor the biological performance of a small-scale sequencing batch reactor (SBR). We created soft sensors using en...
Conference Paper
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Decisions made on the degree of centralisation of wastewater treatment systems are often not cost optimal. Eggimann et al. (submitted) found that in particular Austria, Luxemburg, and Switzerland have connected more houses to centralised systems than what economics would suggest. This is partly because the alternative to centralised systems, on-sit...
Article
The identification of appropriate sanitation systems is particularly challenging in developing urban areas where local needs are not met by conventional solutions. While structured decision-making frameworks such as Community-Led Urban Environmental Sanitation (CLUES) can help facilitate this process, they require a set of sanitation system options...
Article
Full-text available
Urban water management represents a core economic sector exposed to global water-related challenges. Recently, small modular system configurations have been identified to enable a potential sustainability transi- tion in this lasting and rather conservative sector. The identification of current market potentials of decentralised wastewater treatmen...
Article
Investigations involving human faeces and faecal sludge are of great importance for urban sanitation, such as operation and maintenance of sewer systems, or implementation of faecal sludge management. However, working with real faecal matter is difficult as it not only involves working with a pathogenic, malodorous material but also individual faec...
Data
Supporting information file. Details in the respective sub-chapters on A) scenario assumptions, B) objectives and attributes assessment, C) stakeholder preferences, D) uncertainty and simulation assumptions, and E) additional results. (PDF)
Article
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We compare the use of multi-criteria decision analysis (MCDA)–or more precisely, models used in multi-attribute value theory (MAVT)–to integrated assessment (IA) models for supporting long-term water supply planning in a small town case study in Switzerland. They are used to evaluate thirteen system scale water supply alternatives in four future sc...
Article
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The promise of collecting and utilising large amounts of data has never been greater in the history of urban water management (UWM). This paper reviews several data-driven approaches which play a key role in bringing forward a sea change. It critically investigates whether data-driven UWM offers a promising foundation for addressing current challen...
Article
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To determine the optimal connection rate (CR) for regional waste water treatment is a challenge that has recently gained the attention of academia and professional circles throughout the world. We contribute to this debate by proposing a framework for a total cost assessment of sanitation infrastructures in a given region for the whole range of pos...
Article
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Decentralised wastewater treatment is increasingly gaining interest as a means of responding to sustainability challenges. Cost comparisons are a crucial element of any sustainability assessment. While the cost characteristics of centralised waste water management systems (WMS) have been studied extensively, the economics of decentralised WMS are l...
Article
The top priorities for urban water sustainability include the provision of safe drinking water, wastewater handling for public health, and protection against flooding. However, rapidly aging infrastructure, population growth, and increasing urbanization call into question current urban water management strategies, especially in the fast-growing urb...
Article
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The strong reliance of most utility services on centralised network infrastructures is becoming increasingly challenged by new technological advances in decentralised alternatives. However, not enough effort has been made to develop planning tools designed to address the implications of these new opportunities and to determine the optimal degree of...
Article
Urban drainage design relying on observed precipitation series neglects the uncertainties associated with current and indeed future climate variability. Urban drainage design is further affected by the large stochastic variability of precipitation extremes and sampling errors arising from the short observation periods of extreme precipitation. Stoc...
Article
Water supply and wastewater infrastructures are vital for human well-being and environmental protection; they adhere to the highest standards, are expensive and long-lived. Because they are also aging, substantial planning is required. Climate and socio-economic change create large planning uncertainties and simple projections of past developments...
Article
Accurate predictions of future conditions of sewer systems are needed for efficient rehabilitation planning. For this purpose, a range of sewer deterioration models has been proposed which can be improved by calibration with observed sewer condition data. However, if datasets lack historical records, calibration requires a combination of deteriorat...
Article
A generic model is introduced that is capable of quantitatively representing the combined sewer infrastructure of a settlement. It consists of a catchment area module, which calculates the length and size distribution of the needed sewer pipes on the basis of rain, housing densities and area size. These results are fed into the sewer construction c...
Article
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Predictions of the expected number of failures of water distribution network pipes are important to develop an optimal management strategy. A number of probabilistic pipe failure models have been proposed in the literature for this purpose. They have to be calibrated on failure records. However, common data management practices mean that replaced p...
Article
The presented approach aims to overcome the scarce data problem in service life modeling of water networks by combining subjective expert knowledge and local replacement data. A procedure to elicit imprecise quantile estimates of survival functions from experts, considering common cognitive biases, was developed and applied. The individual expert p...
Article
Climate change scenarios predict an increase of extreme rain events, which will increase the risk of wastewater flooding and of missing legal water quality targets. This study elicits the willingness to pay to reduce ecological and health risks from combined sewer overflows in rivers and lakes, and wastewater flooding of residential and commercial...
Article
The assessment and validation of sewer deterioration models is difficult because reliable data are missing. This makes it hard to find the most suitable model for a particular application. A network condition simulator (NetCoS) is used to generate synthetic sewer data for defined test scenarios. Thereby, the deterioration and replacement of pipes,...
Article
Regarding multi-criteria decision analysis (MCDA), the problem of generating alternatives has not received the attention it deserves. Most research is currently devoted to the problem of alternative selection, where it is assumed that a set of appropriate alternatives is already given. This paper addresses the generation of potential alternatives i...
Article
Distributed (decentralized) wastewater treatment can, in many situations, be a valuable alternative to a centralized sewer network and wastewater treatment plant. However, it is critical for its acceptance whether the same overall treatment performance can be achieved without on-site staff, and whether its performance can be measured. In this paper...
Chapter
Source separation and decentralization for better resource management in wastewater treatment are gaining ground. This chapter summarizes the rationale for this development, followed by an extensive review of the literature on source-separated gray water, urine, and feces. For comparison, a short section on decentralized treatment of combined domes...
Article
Switzerland provides an example of successful management of water infrastructure and water resources that was accomplished largely without integration across sectors. Limitations in this approach have become apparent; decisions that were formerly based only on technical and economic feasibility must now incorporate broader objectives such as ecolog...
Article
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An accurate description of aging and deterioration of urban drainage systems is necessary for optimal investment and rehabilitation planning. Due to a general lack of suitable datasets, network condition models are rarely validated, and if so with varying levels of success. We therefore propose a novel network condition simulator (NetCoS) that prod...
Article
Urine source separation (NoMix technology) followed by processing the concentrated nutrient solution has the potential to become a cost-efficient alternative to conventional end-of-pipe nutrient elimination. A choice of processing technologies can only be made for specific scenarios, and there is currently no methodology for analyzing generic situa...
Article
Sustainability transitions have repeatedly been demanded in various economic sectors to confront global environmental problems. The present paper analyses the role of strategic planning processes for improving the prospects of achieving sustainable transitions in infrastructure sectors. Current planning approaches in these sectors tend to perpetuat...
Article
A generic model is introduced that represents the combined sewer infrastructure of a settlement quantitatively. A catchment area module first calculates the length and size distribution of the required sewer pipes on the basis of rain patterns, housing densities and area size. These results are fed into the sewer-cost module in order to estimate th...
Article
Struvite crystallisation is a fast and reliable phosphorus removal and recovery process for concentrated waste streams - such as hydrolysed human urine. In order to optimise P-elimination efficiency, it is beneficial to obtain larger particle sizes: they are easier to separate and less prone to wash-out than smaller particles. This paper presents t...
Article
Planning of urban water and wastewater infrastructures is based on assumptions about the long- term future of the service area. Important factors, such as demand development, carry large uncertainties and have a substantial impact on plant size and ultimately on costs. In this paper we attempt to quantify the economic consequences of these uncertai...
Article
The sustainable transformation of infrastructure sectors represents a challenge of prime importance worldwide. Due to long life times of infrastructures, strategic decision making has to explicitly consider uncertainties in context conditions, value considerations and available technological alternatives. However currently, strategic infrastructure...
Article
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The example of urine reveals the large potential of source separation technologies for sustainable and resource efficient future urban wastewater management. [GRAPHICS]
Article
A specific net present value (SNPV) approach is introduced as a criterion in economic engineering decisions. The SNPV expresses average costs, including the growth rate and plant utilisation over the planning horizon, factors that are excluded from a standard net present value approach. The use of SNPV favours alternatives that are cheaper per serv...
Article
Practical and theoretically sound methods for analyzing innovative environmental technologies are needed to inform public and private decisions regarding research and development, risk management, and stakeholder communication. By integrating scientific assessments with a characterization of values, multicriteria decision analysis (MCDA) supports t...
Article
Separating urine from wastewater at the source reduces the costs of extensive wastewater treatment. Recovering the nutrients from urine and reusing them for agricultural purposes adds resource saving to the benefits. Phosphate can be recovered in the form of struvite (magnesium ammonium phosphate). In this paper, the behaviour of pharmaceuticals an...
Article
beta-Blockers are used to treat high blood pressure as well as patients recovering from heart attacks. In several studies, they were detected in surface water, thus indicating incomplete degradability of these substances in sewage treatment plants (STPs). In this study, we determined the sorption coefficients (K(D)) and degradation rates of the fou...
Article
Struvite (MgNH(4)PO(4).6H(2)O) precipitation eliminates phosphate efficiently from urine, a small but highly concentrated stream in the total flux of domestic wastewater. Precipitation experiments with hydrolysed urine evaluated the solubility product of struvite. The stored and fully hydrolysed urine had an ionic strength of between 0.33 and 0.56M...
Article
We look at the most important issues of the global nitrogen and phosphorus cycle and conclude that the nutrients from human metabolism are of no importance for the global nitrogen cycle and of minor importance for the global phosphorus cycle. However, for water pollution control, N and P from the human metabolism are of extreme importance. Nitrogen...
Article
Urine can be collected separately from the general wastewater with the aim of recycling the nutrients. Urine source-separation not only prevents wasting nutrients but also prevents potentially hazardous micropollutants from entering the wastewater stream and tainting a final fertilizer product. We assessed various urine treatment technologies for t...
Article
In this paper we estimate at what cost decentralised wastewater treatment can be competitive compared with conventional centralised technologies. For the current wastewater infrastructure in Western Europe and North America, typical replacement costs are 2,600 US$/cap for large countries and 4,800 US$/cap for small ones. In the same literature, ave...
Article
The intrinsic bioremediation of BTEX must be documented by the stoichiometric consumption and production of several other compounds, called 'footprints' of the biodegradation reaction. Although footprints of BTEX biodegradation are easy to identify from reaction stoichiometry, they can be confounded by the stepwise nature of the biodegradation reac...
Article
A test battery for identifying ecotoxicological hazards was applied to six pharmaceuticals (carbamazepine, diclofenac, ethinylestradiol, ibuprofen, propranolol, and sulfamethoxazole), to their mixtures, and to urine spiked with pharmaceuticals to test the suitability of biotests for screening urine and wastewater and for monitoring the efficiency o...
Article
This paper provides the details of the Coupled Biological and Chemical (CBC) model for representing in situ bioremediation of BTEX. The CBC model contains novel features that allow it to comprehensively track the footprints of BTEX bioremediation, even when the fate of those footprints is confounded by abiotic reactions and complex interactions amo...
Article
Wastewater treatment was primarily implemented to enhance urban hygiene. Treatment methods were improved to ensure environmental protection by nutrient removal processes. In this way, energy is consumed and resources like potentially useful minerals and drinking water are disposed of. An integrated management of assets, including drinking water, su...
Article
The analysis of different removal and recovery techniques for nutrients in urine shows that in many cases recovery is energetically more efficient than removal and new-production from natural resources. Considering only the running electricity and fossil energy requirements for the traditional way of wastewater treatment and fertiliser production,...
Article
Municipal wastewater treatment systems that depend on centralized biological treatment are increasingly burdened with pollutant loads that they were never intended to handle, say Tove Larsen and co-workers at the Swiss Federal Institute for Environmental Science and Technology. The researchers are exploring redesigned systems, beginning with novel...
Article
Full-text available
Water infrastructure in general and sanitation in particular are confronted increasingly with uncertain context conditions, a broadened spectrum of alternative system configurations and an increasing heterogeneity of value positions from which alternatives have to be assessed. All these uncertainties have to be taken into account to determine susta...

Citations

... Concerning the spatial scale of the green space network, studies have been conducted at a variety of spatial scales, including the city [38], central city [39], and watershed [34]. In addition, studies have shown that building a network of green spaces can manage stormwater [40], optimize the layout of green infrastructure [41] and harmonize cities with nature [42]. Currently, urban green space network models are maturing. ...
... In India and Bangladesh, the holistic approach of offsite and onsite is taken side by side (Narayan et al. 2021a). Citywide inclusive sanitation (CWIS) targets safe sanitation provision for everyone either connected by a centralized/decentralized sewerage system or utilizing OSS (Narayan et al. 2021b). The current policies in Pakistan are completely ignoring this component. ...
... In sewer networks with typical ranges of slopes of 0.3-3%, 50% reduction in wastewater flows results in a minimum of 7%, maximum of 49% and median of 23% of all the pipes in the network accumulating solids (for all stream orders), an increase of 3-20% from the base scenario, i.e., when DWES are not implemented, was characterised by a minimum of 4%, maximum of 19% and median of 12% of pipes accumulating solids (Fig. 2a, b). These results follow previous studies' findings conducted on a limited number of case studies (e.g., Penn and Maurer, 2021). Examination of the full range of slopes of 0.3-10% revealed that the percentage of pipes accumulating solids was significantly reduced in comparison to the range 0.3-3% (Fig. 2b). ...
... not knowing where drain inlets are located nor their hydraulic characteristics, hinders comprehensive infrastructure asset management. The lack of information is alarming, when considering the immense replacement cost of urban drainage infrastructure (in Switzerland it amounts to 100 billion Swiss Francs (Hoffmann, Hunkeler, and Maurer 2014), which corresponds to approximately 10,700 Euros per inhabitant). Additionally, most urban construction work requires detailed and accurate maps of underground infrastructure to prevent damage and service interruptions. ...
... Therefore, giving priority to IT, RB, and VS, and also to ease the applicability in real cases (less complex and expensive sewage systems), D3 was chosen as the spatial distribution for SUDS. Overall, it was concluded that because the SUDS modify the hydraulic and hydrological patterns of the catchment, their spatial distribution will be a determining variable in these modifications, and for this reason it is essential to define adequately what is the best distribution, as also stated by other authors (Tedoldi et al. 2017;Joshi et al. 2021;Fenner 2017). Content courtesy of Springer Nature, terms of use apply. ...
... SANitation system Alternative GeneratOr (Santiago) is a free software capable of generating system options for urban planning based on a set of criteria. The approach has been tested in different locations, such as the cities of Arba Minch (Ethiopia), Lima (Peru), and Katarniya (Nepal), where it has been found to be systematic and reproducible (Nisaa et al., 2021;Spuhler et al., 2018Spuhler et al., , 2021. The cases showed it to be capable of providing substantial benefits, as it opens up the decision space with novel and potentially more appropriate solutions. ...
... To the best of our knowledge, most water quality sensors are designed and manufactured to achieve a response that is as linear as possible. Given that these are most prone to drift, we believe water quality sensor design and manufacturing practices should move away from specifying linearity as a requirement and consider the benefits of nonlinear features in the produced signal, especially when considered for remote or unstaffed systems (Schneider et al., 2019(Schneider et al., , 2020. ...
... Believing that the sludge had been activated the process was named activated sludge. Not until much later was it realized that what had actually occurred was a means to concentrate biological organisms, decoupling the liquid retention time from the solids retention time.Their results were published in their seminal 1914 paper, and the first full-scale continuous-flow system was installed at Worcester two years later (Spuhler et al, 2020). Sewage treatment (or domestic wastewater treatment, municipal wastewater treatment) is a type of wastewater treatment which aims to remove contaminants from sewage to produce an effluent that is suitable for discharge to the surrounding environment or an intended reuse application, thereby preventing water pollution from raw sewage discharges. ...
... Cities around the world are facing persistent environmental problems such as climate change, pollution, biodiversity loss and resource depletion (Steffen et al., 2015). Within the urban water sector, there are concerns about the ability of conventional water systems to adequately meet current and projected challenges such as rapid urbanisation, water scarcity and climate change impacts Grigg, 2019(Hoffmann et al., 2020. Thus, the idea of Water Sensitive Design (WSD) has gained purchase as a suite of complementary Nature-based Solution (NbS) to conventional water management systems, and as one way of transitioning towards water resilient futures (Albert et al., 2019;Radcliffe, 2019;Zevenbergen et al., 2018). ...
... Usually linear additive aggregation is applied, but many non-compensatory models are possible, which may better represent stakeholder preferences (Haag et al., 2019a;Reichert et al., 2015Reichert et al., , 2019. (vi) MAVT and MAUT allow inclusion of various types of uncertainty, e.g., of expert predictions with probability theory or stakeholder preferences with sensitivity analyses (Reichert et al., 2015;Haag et al., 2019b;Zheng et al., 2016). (vii) MCDA is done stepwise to reduce complexity and increase transparency. ...