Toward Zero Hunger Through Coupled Ecological Sanitation-Agriculture Systems

Ecological sanitation (EcoSan) systems capture and sanitize human excreta and generate organic nutrient resources that can support more sustainable nutrient management in agricultural ecosystems. An emerging EcoSan system that is implemented in Haiti and several other contexts globally couples container-based household toilets with aerobic, thermophilic composting. This closed loop sanitation system generates organic nutrient resources that can be used as part of an ecological approach to soil nutrient management and thus has the potential to contribute to Sustainable Development Goals 2 (zero hunger), 6 (clean water and sanitation for all), and 13 (climate change solutions). However, the role of organic nutrient resources derived from human excreta in food production is poorly studied. We conducted a greenhouse experiment comparing the impact of feces-derived compost on crop production, soil nutrient cycling, and nutrient losses with two amendments produced from wastewater treatment (pelletized biosolids and biofertilizer), urea, and an unfertilized control. Excreta-derived amendments increased crop yields 2.5 times more than urea, but had differing carry-over effects. After a one-time application of compost, crop production remained elevated throughout all six crop cycles. In contrast, the carry-over of crop response lasted two and four crop cycles for biosolids and biofertilizer, respectively, and was absent for urea. Soil carbon concentration in the compost amended soils increased linearly through time from 2.0 to 2.5%, an effect not seen with other treatments. Soil nitrous oxide emissions factors ranged from 0.3% (compost) to 4.6% (biosolids), while nitrogen leaching losses were lowest for biosolids and highest for urea. These results indicate that excreta-derived compost provides plant available nutrients, while improving soil health through the addition of soil organic carbon. It also improved biogeochemical functions, indicating the potential of excreta-derived compost to close nutrient loops if implemented at larger scales. If captured and safely treated through EcoSan, human feces produced in Haiti can meet up to 13, 22, and 11% of major crop needs of nitrogen, phosphorus, and potassium, respectively.

Pratiques Liées aux Représentations Sociales des Excréments Humains chez les Populations des Quartiers Défavorisés du District d’Abidjan en Côte d’Ivoire

La gestion des excréments humains révèle des pratiques à risque pour l’environnement en général et pour la santé des populations en particulier. D’où l’intérêt de cette étude dans les quartiers défavorisés où les difficultés en assainissement sont plus accentuées. La présente recherche s’inscrit dans le cadre d’une approche mixte. Pour ce faire, les méthodes et les techniques correspondant à l’approche qualitative et quantitative ont été utilisées pour collecter les données. Il s’agit, de la grille d’observation, du guide d’entretien et du questionnaire. L’objectif est d’analyser les représentations sociales des excréments humains dans les quartiers défavorisés du District d’Abidjan précisément à bougounisso, sagbé antenne, gbebouto, grand campement, tofiato et zimbabwé. La théorie des représentations sociales développée par Bourdieu a été mobilisée à cet effet. Elle a permis de mettre en exergue les représentations sociales des excréments humains chez les populations des quartiers défavorisés. Les résultats ont montré que la gestion des excréments humains est animée par un ensemble d’idéologie qui se résume en des croyances, des tabous et des sanctions. Il ressort que les différentes définitions des excréments humains se rapportent à la saleté, à l’impureté, aux déchets. Ils sont associés à tout ce qui est synonyme de mal, maladie, malédiction, malheur. Les croyances en rapport avec la gestion des excréments humains sont observées sur le plan religieux et culturel. Ce sont des dispositions relatives au choix du lieu de défécation et des règles d’hygiènes que le croyant doit observer. Les tabous concernent les lieux publics où il est défendu de déféquer. The management of human excreta reveals risky practices for the environment in general and for the health of populations in particular. Hence the interest of this study in disadvantaged neighborhoods where sanitation difficulties are more accentuated. This research subscribe to a mixed approach. To be done, the methods and techniques corresponding to the qualitative and quantitative approach were used to collect the data. These are observation grid, the interview guide and the questionnaire. The objective is to analyse the social representations of human excreta in disadvantaged neighborhoods of the District of Abidjan specifically in bougounisso, sagbé antenne, gbebouto, grand campement, tofiato and zimbabwé. The theory of social representations developed by Bourdieu was used for this purpose. It has made it possible to highlight the social representations of human excreta among populations in disadvantaged neighborhoods. The results showed that in traditional societies the management of human faeces is driven by a set of ideologies that boil down to beliefs, taboos and sanctions developed around human faeces and the act of defecation. It appears that the different definition of human excreta relate to dirt, impurity and waste. They are associated with everything that is synonymous with evil; disease, curse, misfortune. Beliefs related to the management of human excreta are observed on a religious and cultural level. These provisions relating of the choice of the place of defecation and the rules of hygiene that the believer must observe. The taboos refers to public places where defecation is forbidden.

Technologies for recovery and reuse of plant nutrients from human excreta and domestic wastewater: a protocol for a systematic map and living evidence platform

Background Research and development on the recovery and reuse of nutrients found in human excreta and domestic wastewater has intensified over the past years, continuously producing new knowledge and technologies. However, research impact and knowledge transfer are limited. In particular, uptake and upscaling of new and innovative solutions in practice remain a key challenge. Achieving a more circular use of nutrients thus goes beyond technological innovation and will benefit from a synthesis of existing research being readily available to various stakeholders in the field. The aim of the systematic map and online evidence platform described in this protocol is threefold. First, to collate and summarise scientific research on technologies that facilitate the recovery and reuse of plant nutrients and organic matter found in human excreta and domestic and municipal wastewater. Second, to present this evidence in a way that can be easily navigated by stakeholders. Third, to report on new relevant research evidence to stakeholders as it becomes available. Methods Firstly, we will produce a baseline systematic map, which will consist of an extension of two previous related syntheses. In a next stage, with help of machine learning and other automation technologies, the baseline systematic map will be transformed into ‘living mode’ that allows for a continually updated evidence platform. The baseline systematic map searches will be performed in 4 bibliographic sources and Google Scholar. All searches will be performed in English. Coding and meta-data extraction will include bibliographic information, locations as well as the recovery and reuse pathways. The living mode will mostly rely on automation technologies in EPPI-Reviewer and the Microsoft Academic database. The new records will be automatically identified and ranked in terms of eligibility. Records above a certain ‘cut-off’ threshold will be manually screened for eligibility. The threshold will be devised based on the empirically informed machine learning model. The evidence from the baseline systematic map and living mode will be embedded in an online evidence platform that in an interactive manner allows stakeholders to visualise and explore the systematic map findings, including knowledge gaps and clusters.

Qualitative Risk Analysis for Contents of Dry Toilets Used to Produce Novel Recycling Fertilizers

Human excreta are a sustainable, economical source of nutrients, and can be used to produce recycling fertilizer for horticulture by collecting and processing the contents of dry toilets. Herein, we discuss the key categories of risk associated with the main groups of materials commonly found in dry toilets. The study was part of the development of a German product standard for marketable and quality-assured recycling fertilizers from human excreta for use in horticulture. Particular attention is paid to ensuring that the fertilizer is epidemiologically and environmentally harmless and that the quality of the recycling fertilizer is adequate in terms of low pollution and nutrient availability. In sum, the risk of transmissible human pathogens lies within the human excreta, particularly feces; plant materials added during composting are of particular phytosanitary relevance; pharmaceutical residues in excrements and chemical additives are potential sources of pollutants; non-biodegradable contaminants can cause pollution and injury; and the horticultural risks involve mainly the ammonia emission potential and in some cases the salinity effects of urine. These risks can be reduced significantly (i) with education of users around proper operation of dry toilets and the consequences of adding inappropriate waste, (ii) with facilitation of proper use with general waste bins and clear instructions, and importantly (iii) by using modern sanitization and cleaning processes and testing for harmful substances under the guidance of local laws and regulations, ensuring safe and high-quality fertilizers. In conclusion, the benefits of using dry toilet contents to produce fertilizers for use in horticulture are unquestionable. Our analysis highlights the need to support recycling optimization and awareness for the purpose of a sustainable circular economy and to minimize the risk of harm to humans and the environment overall.

Manual Scavenging in India: The Banality of An Everyday Crime

Manual scavenging is the practice of ‘manually cleaning, carrying, disposing of, or otherwise handling, human excreta in an insanitary latrine or in an open drain or pit’, and its existence is a crime of genocidal proportions. The vast majority of people forced into this degrading occupation are women from Dalit castes. The Government of India has outlawed the practice through two Acts of 1993 and 2013, yet it continues everywhere in the country. This essay argues that the persistence of this crime is a consequence of the criminal indifference of a casteist society, and that resistance to it has largely been the heroic effort of the victims alone.