Reuse Of Excreta Research Articles

Psychometric analysis of the ecological dispositions of rural farming communities in South Africa: Implications for human excreta reuse in agriculture

The established link between anthropogenic activities and environmental problems calls for the understanding of public perceptions of the environment. Circular bioeconomy approaches promote sustainable and resilient food systems, and are critical to address soil, human, and environmental health. This study endeavours to understand the ecological worldviews of rural farming communities and implications for human excreta reuse in agriculture. The study adopted the social psychology theory and the new ecological paradigm scale, which measures environmental attitudes. The Cronbach’s alpha factoring indicated high internal consistency and reliability of the questions. The results show that rural farmers are moderately environmentally conscious. The hierarchical regression results show that age, education, and household income negatively influence environmental attitudes. Pro-environmental farmers perceived lower health risk and believed that they were more capable of using human excreta. The study recommends that the reuse of human excreta in agriculture be marketed as a sustainable and environmentally friendly innovation to increase social acceptance by rural farmers in agri-food systems.

China should focus beyond access to toilets to tap into the full potential of its Rural Toilet Revolution

In China, over 47 million toilets in rural areas have been upgraded since the nationwide sanitation program, popularly referred to as the “toilet revolution”, was launched in 2015. However, little is known about the perceptions of rural households regarding these new toilets or the fate of human excreta collected using them. To investigate the other side of the toilet revolution, we surveyed 980 rural households from 22 provinces across China in 2020. We found that most households used an on-site sanitation system (i.e. septic tanks and pit latrines), where urine and feces were mixed and collected (88%), stored in pits or tanks (79%), emptied by the households themselves (60%), applied on farmland as fertilizer (45%), or used for biogas production (5%). Despite the toilet revolution-driven infrastructure upgrade, only 25% of the households were satisfied with their sanitation system and pointed to health risks from issues in the toilet interface and the treatment and reuse of excreta as areas of concern. The majority preferred an “out of sight, out of mind” approach, in which the local government handles excreta without involving the households and without asking them to pay for such management. Meanwhile, 80% supported the idea of local nutrient recycling and believed that human excreta should return to farmland as fertilizer or used for biogas production. Our findings suggest that decision makers in local governments across China must urgently explore ways to upgrade all parts of the sanitation service chain so that rural sanitation can be truly improved to positively influence the progress on other national sustainability goals.

Poor awareness and attitudes to sanitation servicing can impede China's Rural Toilet Revolution: Evidence from Western China

The ongoing Toilet Revolution in China offers an opportunity to improve sanitation in rural areas by introducing new approaches, such as urine source separation, that can contribute to achieving SDG6. However, few studies have systematically assessed the social acceptability of managing human excreta collected in new sanitation systems. Therefore, in this study we performed face-to-face interviews with 414 local residents from 13 villages across three provinces in western China, to analyze the current situation and attitudes to possible changes in the rural sanitation service chain. We found that the sanitation chain was predominantly pit latrine-based, with 86.2% of households surveyed collecting their excreta in a simple pit, 82% manually emptying their pits, and 80.2% reusing excreta in agriculture without adequate pre-treatment. A majority (72%) of the households had a generally positive attitude to production of human excreta-derived fertilizer, but only 24% agreed that urine and feces should be collected separately. Multivariate logistic regression indicated that three factors (level of education, number of permanent household residents, perceived social acceptability) significantly influenced respondents' attitudes to reuse of excreta, although only perceived social acceptability had a high strength of association. Overall, our survey revealed that rural households often misuse toilet systems, fail to comply with government-specified sanitation guidelines, have low awareness of alternative solutions, and are over-reliant on the government to fix problems in the service chain. Thus while new sanitation technologies should be developed and implemented, information campaigns that encourage rural households to manage their excreta safely are also important.

Indigenous Knowledge and Acceptability of Treated Effluent in Agriculture

The twin challenges of lack of access to improved sanitation and food insecurity remain critical, particularly in the global south. With cognizance of the nutrient potential of human excreta, there has been increasing interest in linking sanitation innovations with agriculture by using nutrients recovered from human excreta for crop production, thus, closing the nutrient loop. While studies and field trials have explored and validated the technical feasibility of reusing nutrients recovered from human excreta in agriculture, there is still limited knowledge of its social acceptability. This study examined whether indigenous knowledge can be leveraged to increase the acceptability of human-excreta-derived plant nutrient sources such as treated effluent in agriculture. A qualitative research design comprising seven focus group interviews (five in rural areas and two in peri-urban areas) was conducted in KwaZulu Natal, South Africa. Findings from the focus groups reveal a willingness to grow and consume food using treated effluent. Additionally, participants made references to indigenous practices that encourage recycling and reuse of human excreta. Given the potential to simultaneously address issues of food insecurity and sanitation that characterize many peri-urban and rural areas in South Africa, we recommend further studies in this area.

Novel NoMix toilet concept for efficient separation of urine and feces and its design optimization using computational fluid mechanics

Separation of urine from feces in NoMix toilets bears a large potential for mitigating problems associated with the efficient reuse of excreta. A challenge lies in the design of these toilets that should maximize the amount of collected urine while at the same time minimizing its mixing with flush water that partly spills into the urine collector. We present a novel design idea that takes advantage of the so-called tea pot effect, which describes the attachment of liquids to a curved wall due to surface tension. This effect is used to efficiently guide the urine along a curved entrance into the collector. Computational Fluid Dynamics (CFD) simulations of the two phase (water/urine - air) system are carried out on different toilet geometries where we vary the inflow to the urine collector. In particular, we investigate two different radial curvatures and two V-profile grooves whose combinations result in four toilet geometries that are tested. We demonstrate that the urine collection can be dramatically improved by tailoring curvature radius and V-profile grooves, while keeping the amount of flush water in the urine collector at a minimum. A reduction to less than 2.5% of flush water entering the urine collector could be achieved by implementing a curvature radius of 15 mm and a V-profile groove width of 60 mm. The improved geometry's performance makes it an appealing candidate for broad application both in western and developing countries and we anticipate that this technology might replace traditional toilet designs in the future.

Return to learn: recommendations from revisited rural ecosan projects in Burkina Faso

Burkina Faso has extensive experience with urine-diverting dry toilets (UDDTs) and the reuse of human excreta in agriculture in line with the ecological sanitation (ecosan) principles of containment, treatment, and reuse. Around 30 such ecosan projects have been implemented over the past 15 years, including installation of approximately 13,500 household UDDTs, accompanied by awareness-building and training on toilet use, emptying, and reuse. Recently, efforts have been made to revisit former and current project sites in the spirit of ‘return to learn’. We identified four such learning initiatives (studies/events), from which we draw recommendations to improve the sustainability of future implementation of ecosan in Burkina Faso and similar contexts. Key recommendations include increased attention to different user needs, handwashing and training on emptying/reuse as well as research and innovation on toilet design, urine collection/handling, menstrual management, and cost reduction/financing. Burkina Faso has set up the ambitious goal of 100 per cent toilet coverage and optimal reuse in the national sanitation programme by 2030, with UDDTs projected to make up 15 per cent of the 2 million toilets needed in rural areas. It is therefore timely to take stock and learn from past interventions. In addition, to enable resource recovery and reuse at scale, it will be important to develop a supportive policy and legal framework with collaboration between the WASH, agriculture, health, and environmental sectors.

Monitoring sanitation performance: unpacking the figures on sanitation coverage

An understanding of the sanitation situation is crucial for planning and evaluating effectiveness of sanitation interventions. Such knowledge is gained through monitoring sanitation performance. At the international level, sanitation monitoring is done by the Joint Monitoring Programme (JMP) of the World Health Organization (WHO) and United Nations Children's Fund (UNICEF). The JMP tracks progress made towards the Millennium Development Goal (MDG) sanitation target using information collected from household surveys. This article critically describes and reviews the JMP sanitation monitoring approach based on information from literature. The paper argues that while JMP methods have been useful in reporting sanitation progress, it has a number of weaknesses which have led to questions being raised on the sanitation coverage figures. Specifically, the JMP has been criticized for its usage of the term ‘improved’ sanitation and the technology-based sanitation ladder. It is argued that this approach does not monitor other components of sanitation systems such as storage, transport, treatment and disposal and/or re-use of human excreta. In addition, the sustainability of the sanitation systems is also overlooked. All these factors have led to an overestimation of sanitation coverage. A monitoring approach which considers the function of sanitation and sustainability of sanitation systems is therefore recommended.

Peepoo bag: self-sanitising single use biodegradable toilet

Unsafe water, sanitation and hygiene together with deficient nutritional status are major contributors to the global burden of disease. Safe collection, disposal and reuse of human excreta would enable the risk of transmission of diseases to be decreased and household food security to be increased in many regions. However, the majority of the 2.5 billion people lacking improved sanitation comprise poor people in societies with weak infrastructure. This study developed a low cost sanitation option requiring little investment and maintenance--a single use, self-sanitising, biodegradable toilet (Peepoo bag) and tested it for smell, degradability and hygiene aspects. It was found that no smell was detectable from a 25 microm thick bag filled with faeces during 24 h in a 10 m2 room at 30 degrees C. Bags that had been in contact with urea-treated faeces or urine for 2 months in air, compost or water at 24 or 37 degrees C showed little signs of degradation. Furthermore, pathogen inactivation modelling of the 4 g of urea present in the bag indicated that appropriate sanitation of faecal material collected is achieved in the bag within 2-4 weeks, after which the bag can be degraded and reused as fertiliser.

Wastewater management in Kunming, China: a stakeholder perspective on measures at the source

Large sewer systems with central wastewater treatment plants were long considered a successful model that could be exported to practically any city of the world. This centralized, highly water-consuming system has, however, shown its limits in some developing and transition countries, especially in fast-growing cities with limited water resources. This study from around Lake Dianchi in Yunnan, China, investigated the feasibility of introducing measures at the source for the different urban wastewater contributions in the city of Kunming, and the stakeholder perspectives on this approach. In addition, the stakeholders evaluated the potential of two different sanitation alternatives that allowed the separation and re-use of human excreta as fertilizer. Most of those interviewed approved of measures at the source, especially for industrial wastewater and toilet waste. There was a prevailing optimism with respect to the potential of technical developments and the likelihood of increased environmental awareness within a relatively short time span of 20 years. The findings suggest that China will prove to be one of the most interesting and productive “laboratories” for the development of decentralized wastewater treatment alternatives.

An assessment of the effect of human faeces and urine on maize production and water productivity

The key challenge facing many catchment authorities in Zimbabwe and elsewhere is the challenge of feeding the growing populations within their catchment boundaries. Modern agricultural practices continue to mine valuable crop nutrients through increased food production to satisfy ever-increasing food demand. In recent diagnostic survey of smallholder agricultural sector in the Manyame catchments of Zimbabwe it was revealed that exhausted soils depleted of their natural mineral and organic constituents by many years of cropping with little fertilization or manuring were the major factors contributing to low yields and poor food security in this sector in Zimbabwe. The objective of the study was to assess the effect of using sanitized human excreta on maize production and water productivity. The study involved six volunteer farmers with four 10 m × 10 m trial plots each with the following treatments the control, commercial fertilizer treatment urine only plot, and the feacal matter and urine plot. Harvest determination was carried by weighing the yield from each of the treatment plots and comparisons done. Water productivity was computed by calculating the amount of water used to produce a tone of maize per ha. The study showed that human excreta improves maize crop production and water productivity in rain-fed agriculture. The study recommends that the ecological sanitation concept and the reuse of human excreta both humanure and (ecofert) urine can be considered as alternative excreta management options in catchment areas.