Pre-selecting appropriate sanitation system options as an input into urban sanitation planning

Structured decision making (SDM) frameworks such as CLUES and Sanitation21 support urban sanitation planning by prioritizing decision objectives, identifying decision options, quantifying consequences, clarifying trade-offs, and balancing for opposing stakeholder preferences. However, current research focusses on the selection of a preferred option, assuming that the options to choose from are already known. Given the growing number of sanitation technology and system configurations, as well as the multiple criteria that those should fulfil, providing a good set of decision options is far from trivial. In this paper we present an approach for the pre-selection of locally appropriate sanitation system options that: (1) is systematic and therefore transparent; (2) is based on stakeholder objectives, thus increasing ownership; (3) can deal with a large number of both conventional and novel options opening up the decision space; and (4) considers uncertainties related to novel technologies and the local conditions

Adapting Santiago method to determine appropriate and resource efficient sanitation systems for an urban settlement in Lima Peru

The pre-selection of locally appropriate sanitation technologies and systems is crucial for strategic sanitation planning as any decision is only as good as the options presented. One approach that allows us to systematically consider the local conditions and a diverse range of conventional and novel technologies and systems is the Santiago method. In this paper, we discuss whether the Santiago method can be applied to the case of Latin America and what we would gain from this application. We do so by expanding the Santiago technology library with technologies that have been shown to be promising in metropolitan areas of Latin America, such as condominial sewer, container-based sanitation, and activated sludge. We then apply Santiago to the semi-informal settlement Quebrada Verde (QV) in Lima, Peru. Using Santiago, we were able to generate 265,185 sanitation system options from 42 technologies and 18 appropriateness criteria. A set of 17 appropriate and divers are then selected. The diversity is defined by 17 system templates. To further evaluate these 17 systems, resource recovery and loss potentials are quantified. Higher nutrients (nitrogen and phosphorus) and total solids recovery are observed for systems that combine urine diversion and biofuel production. The case of QV shows that the Santiago method is applicable in the Latin American context.Bundesministerium für Bildung und Forschun

Solar disinfection is an augmentable, in situ-generated photo-Fenton reaction—Part 1: A review of the mechanisms and the fundamental aspects of the process

The present manuscript is a conceptual review concerning the photo-Fenton reaction at near-neutral pH, used for bacterial inactivation. In this first Part, an overview of the mechanisms involved, as well as the fundamental concepts governing the near-neutral photo-Fenton reaction are critically assessed. The two constituents of the process, namely solar light and the Fenton reagents, are dissociated, with their direct and indirect actions thoroughly analyzed. The effects of UVB and UVA on the bacterial cell are firstly discussed, followed by the presentation of the indirect oxidative stress-related inactivation mechanisms initiated into the microorganism, in presence of light. Afterwards, the effect of each Fenton reagent (H2O2, Fe) is analyzed in a step-wise manner, with H2O2 and Fe as enhancements of the solar disinfection mode of action. This approach proves that in fact, the solar photo-Fenton reaction is an enhanced solar disinfection process. Finally, the photo-Fenton reaction is put into context by considering the possible interactions of the separate parts of the combined process with the constituents of the natural environment that can play an important role in the evolution of the bacterial inactivation. (C) 2016 Elsevier B.V. All rights reserved

Generation and evaluation of sanitation options for urban planning: systematic consideration of technology innovations and sustainability criteria

To make urban water management more sustainable, many novel sanitation technologies and system configurations have been developed recently. Many of these innovations allow for resource recovery and reuse and are independent from energy, water, and sewer networks. This makes them more resilient to changing environmental and socio-demographic conditions and thus more appropriate for developing urban areas. But while novel technologies and systems potentially enhance sustainability, they also increase planning complexity: how can the different technologies be assembled into entire systems? How appropriate are the resulting systems for a given application case? And how can relevant sustainability indicators such as resource recovery and losses be quantified? This thesis contributes with a theoretical description, implementation, and practical applications of methods for: (1) the generation of all valid system configurations from a set of potential technologies considering innovations; (2) the identification of a set of locally appropriate systems as an input into strategic planning using a structured decision-making approach; and (3) the ex-ante quantification of resource recovery potentials of entire systems consider. The methods are generic to be applied to any case or (future) technology, flexible to fit into any international established planning procedures; automated to consider a diverse and large set of potential options; systematic to enhance transparency; and explicitly consider uncertainty related to technology implementation or the local context. Because one of the main challenges in practice is the lack of knowledge and data, especially for novel technologies, the methods are complemented with a technology library providing international data and expert knowledge to be matched to the local conditions. The practical experiences from six case studies showed that the approach allows the prioritisation of more appropriate and more resource efficient systems when strategically planning for sanitation improvements. As more technology and sanitation system options are added to the already large portfolio, the methods presented in this thesis may become an essential tool for the putting SDG 6.2, 6.3 and SDG 11 into practice

Review of frameworks and tools for urban strategic sanitation planning: considering technology innovations and sustainability.

To achieve citywide inclusive sanitation in developing countries, a strategic sanitation planning approach (SSA) needs to provide a variety of technical solutions that respond to different urban realities. Despite the development of various SSA frameworks, sanitation planning still often follows a ‘one-size-fits-all’ approach. Structured decision making (SDM) can help by balancing trade-offs among different solutions. But SDM requires a set of appropriate sanitation options to choose from. Because conventional sewer-based sanitation is often inappropriate, many novel technologies and systems have been developed (e.g. container-based sanitation). While these innovations enhance sustainability, they also increase planning complexity. In this review, we look at available frameworks and tools for SSA and discover a lack of systematic tools for the identification of planning options that are able to consider the growing portfolio of available solutions and multiple sustainability criteria. Therefore, we critically compare 15 tools from which we compile eight qualities that could help any future tool address the current sanitation challenge: it should be comprehensive, automated to deal with a large number of options, systematic, flexible towards future innovation and should consider all sustainability dimensions, make a contextualized evaluation, allow for participation, and consider uncertainties to be applicable ex-ante also for novel technologies.ISSN:2043-908

Closing Water and Nutrient Cycles in Urban Wastewater Management: How to Make an Academic Software Available to General Practice

Appropriate sanitation is crucial to alleviate pressures on environmental and human health hazards. Conventional (sewered) sanitation systems are often not viable in rapidly developing urban areas, where over 70% of the world population is expected to live in 2050. Freshwater is polluted and valuable resources such as nutrients and organics are lost. At present, many alternative sanitation technologies and systems are being developed with the aim to alleviate these pressures through (1) independency from sewers, water, and energy, therefore better adapted to the needs of fast and uncontrolled developing urban areas; and (2) contribute to a circular economy through the recovery of nutrients, energy, and water for reuse. Unfortunately, these innovations hardly find their way into practice because there exists a lack of data and knowledge to systematically consider them in strategic planning processes. To this end, we have developed SANitaTIon system Alternative GeneratOr (SANTIAGO)—a software that provides a comprehensive list of potential technologies and system configurations and quantifies their local appropriateness as well as their resource recovery and loss potentials. The aim is to provide a manageable but diverse set of decision options together with information needed to rank the alternatives and to select the preferred one in a structured decision making process. To make this software useful for practice, an easily accessible interactive user interface is required that (1) facilitates data collection and input; and (2) the exploration and presentation of results. As a first step in creating this user interface, we develop a framework that summarizes (1) the requirements that arise from practical applications of SANTIAGO, and (2) a comprehensive user understanding on the basis of 21 interviews with international practitioners caught in five personas: capacity developers, engineering experts, planners, researchers, teachers and trainers. This framework aids the development of any academic software into a tool useful for practice and policy makers. Here specifically, it enables contribution to sustainable development goals 6 (clean water and sanitation), and 11 (sustainable cities and communities)

Ex-ante quantification of nutrient, total solids, and water flows in sanitation systems

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 applied for a few options at a time for which implementation examples exist. This paper aims to answer two questions: How can we predict resource recovery and losses of sanitation systems ex-ante at the pre-planning phase? And how can we do this efficiently to consider the entire sanitation system option space? The approach builds on an existing model to create all valid sanitation systems from a set of conventional and emerging technologies and to evaluate their appropriateness for a given application case. It complements the previous model with a Substance Flow Model (SFM) and with transfer coefficients from a technology library to quantify nutrients (phosphorus and nitrogen), total solids (as an indicator for energy and organics), and water flows in sanitation systems ex ante. The transfer coefficients are based on literature data and expert judgement. Uncertainties resulting from the variability of literature data or ignorance of experts are explicitly considered, allowing to assess the robustness of the model output. Any (future) technologies or additional products can easily be added to the library. The model is illustrated with a small didactic example showing how 12 valid system configurations are generated from a few technologies, and how substance flows, recovery ratios, and losses to soil, air, and water are quantified considering uncertainties. The recovery ratios vary between 0 and 28% for phosphorus, 0–10% for nitrogen, 0–26% for total solids, and 0–12% for water. The uncertainties reflect the high variability of the literature data but are comparable to those obtained in studies using a conventional post-ante material flow analysis (generally about 30% variability at the scale of a an urban area). Because the model is fully automated and based on literature data, it can be applied ex-ante to a large and diverse set of possible sanitation systems as shown with a real application case. From the 41 technologies available in the library, 101,548 systems are generated and substance flows are modelled. The resulting recovery ratios range from nothing to almost 100%. The two examples also show that recovery depend on technology interactions and has therefore to be assessed for all possible system configurations and not at the single technology level only. The examples also show that there exist trade-offs among different types of reuse (e.g. energy versus nutrients) or different sustainability indicators (e.g. local appropriateness versus resource recovery). These results show that there is a need for such an automated and generic approach that provides recovery data for all system configurations already at the pre-planning phase. The approach presented enables to integrate transparently the best available knowledge for a growing number of sanitation technologies into a planning process. The resulting resource recovery and loss ratios can be used to prioritise resource efficient systems in sanitation planning, either for the pre-selection or the detailed evaluation of options using e.g. MCDA. The results can also be used to guide future development of technology and system innovations. As resource recovery becomes more relevant and novel sanitation technologies and system options emerge, the approach presents itself as a useful tool for strategic sanitation planning in line with the Sustainable Development Goals (SDGs).ISSN:0301-4797ISSN:1095-863

Tools and capacity development for scaling citywide inclusive sanitation

This record includes an extended abstract and MP4 presentation. Presented at the 42nd WEDC International Conference

The effect of Fe2+, Fe3+, H2O2 and the photo-Fenton reagent at near neutral pH on the solar disinfection (SODIS) at low temperatures of water containing Escherichia coli K12

The effect of Fe2+, Fe3+, H2O2 and the photo-Fenton system (Fe2+or3+/H2O2/hv) on solar water disinfection (SODIS) at low temperature and at near neutral pH are discussed in detail. We focus on Escherichia coil K12 suspended in either MilliQ water, water containing mineral ions and in MilliQ water enriched with resorcinol, a model for natural organic matter (NOM).GPA