Conventional Sanitation Research Articles

Treatment of domestic effluents using sustainable biofilter methods

The discharge of effluents is a permanent environmental and sanitation concern. Efficient water management must include water treatment and reuse. It is therefore necessary to study treatment systems to improve their performance throughout the entire chain, from drinking water to wastewater or, more specifically, waste effluent. Currently, technologies using bio-filtration processes have proven to be an effective and low-cost method for treating industrial effluents and domestic sewage. In this study, a low-cost domestic sewage treatment system made up of biofilters and pipes was built on a bench model as a means of teaching practical classes, and its efficiency was also studied. The results showed that the equipment can be made from recyclable material and is low-cost, easy to detail technically and easy to handle and operate. The students involved can easily replicate the technology in their communities, thus spreading low-cost sanitation treatment technologies to low-income populations without access to conventional sanitation systems. The parameters pH, turbidity, chlorination, temperature, and electrical conductivity were all at acceptable levels for discharge into receiving bodies and domestic use.

Financial comparison of sewage treatment and disposal systems in rural areas

Studies show that conventional sanitation technologies, due to their high costs, end up excluding rural populations. Among the options for the treatment and final disposal of sewage in rural areas we can mention septic tanks with sump and biodigester tanks with filtering gardens. In view of the above, the objective of this article is to make a financial comparison of two individual sewage treatment systems: septic tank with floor drain, and biodigester septic tank with filtering garden. To perform the financial analysis in the case of the septic tank with drain, the amounts were calculated based on the dimensions indicated by ASPROESTE (2018). For the biodigester septic tank with filtering garden, the quantities of materials indicated by ASPROESTE (2018) were adopted for the case of a residence with 5 people. Finally, after the quantities raised, taking as a basis the prices contained in the National Research System of Costs and Indexes of Civil Construction (SINAPI) the costs of implementation of these devices were estimated. The results show that the septic tank system with drain presented a cost of R$ 2580.22 and the biodigester tank system a total cost of R$ 8,682.93. It is concluded that the biodigester septic tank system is more expensive, but allows the reuse of the effluent as biofertilizer, and the values found are relatively high for low-income populations, being indicated the creation of government programs, which deliver these devices for the poorest population.

DMsan: A Multi-Criteria Decision Analysis Framework and Package to Characterize Contextualized Sustainability of Sanitation and Resource Recovery Technologies.

In resource-limited settings, conventional sanitation systems often fail to meet their goals-with system failures stemming from a mismatch among community needs, constraints, and deployed technologies. Although decision-making tools exist to help assess the appropriateness of conventional sanitation systems in a specific context, there is a lack of a holistic decision-making framework to guide sanitation research, development, and deployment (RD&D) of technologies. In this study, we introduce DMsan-an open-source multi-criteria decision analysis Python package that enables users to transparently compare sanitation and resource recovery alternatives and characterize the opportunity space for early-stage technologies. Informed by the methodological choices frequently used in literature, the core structure of DMsan includes five criteria (technical, resource recovery, economic, environmental, and social), 28 indicators, criteria weight scenarios, and indicator weight scenarios tailored to 250 countries/territories, all of which can be adapted by end-users. DMsan integrates with the open-source Python package QSDsan (quantitative sustainable design for sanitation and resource recovery systems) for system design and simulation to calculate quantitative economic (via techno-economic analysis), environmental (via life cycle assessment), and resource recovery indicators under uncertainty. Here, we illustrate the core capabilities of DMsan using an existing, conventional sanitation system and two proposed alternative systems for Bwaise, an informal settlement in Kampala, Uganda. The two example use cases are (i) use by implementation decision makers to enhance decision-making transparency and understand the robustness of sanitation choices given uncertain and/or varying stakeholder input and technology ability and (ii) use by technology developers seeking to identify and expand the opportunity space for their technologies. Through these examples, we demonstrate the utility of DMsan to evaluate sanitation and resource recovery systems tailored to individual contexts and increase transparency in technology evaluations, RD&D prioritization, and context-specific decision making.

Development of ecological sanitation approaches for integrated recovery of biogas, nutrients and clean water from domestic wastewater

Access to adequate sanitation services and the treatment of domestic wastewater becomes a critical problem in developing countries. Domestic wastewater treatment based on conventional sanitation concept is the most common approach, which is neither ecological nor economical sound to realize sustainable sanitation solution. Therefore, there is a need to block the sanitation-linked concerns and limitations of the conventional systems through the development of an alternative sustainable sanitation systems. With the rising demand to improve the existing sanitation system for environmental protection and resources conservation (energy, nutrient, and water), ecological sanitation approach appealed the attention of scientific communities. This paper presents the comprehensive review of domestic wastewater characteristics, conventional sanitation systems and its sustainability challenges; ecological sanitation technologies, process conditions and their performances in terms of resource recovery efficiency (i.e. biogas, struvite-based nutrients and clean water). The outcome of these approaches are resource oriented and closed-loop systems, which promotes the sustainable sanitation by overwhelmed the limitations of conventional systems. Moreover, the application of these technologies to treat domestic wastewater also helps to improve public health by reducing the introduction of disease causing pathogens in to the water cycle and minimizes the negative environmental impacts. Accordingly, the applications of ecological sanitation technologies to treat domestic wastewater would be a viable option to solve the existing sanitation problems; and simultaneously promoting energy-food-water-health nexus, especially in developing country. • Eco-San approaches of DWW in biogas, struvite and clean water recovery is reviewed. • COD removal and biogas recovery potential of various technologies are reported. • Nutrients removal and struvite recovery efficiencies from DWW are described. • The water reuse is based on the stringent water quality standards. • Future research is needed for an integrated recovery of valuables from mixed DWW.

Influence of plasma-treated air on surface microbial communities on freshly harvested lettuce

Plant-based foods like lettuce are an important part of the human diet and worldwide industry. On a global scale, the number of food-associated illnesses increased in the last decades. Conventional lettuce sanitation methods include cleaning either with tap or chloritized water. Beside these water-consuming strategies, physical plasma is an innovative and effective possibility for food sanitation. Recent studies with plasma-treated water showed an effective reduction of the microbial load. Plasma-processed air (PPA) is another great opportunity to reduce the microbial load and save water. To test the efficiency of PPA, the surface microbiome of treated lettuce was analyzed via proliferation assays with special agars, live/dead assays and tests for respiratory activity of the microorganisms. PPA showed a reduction of the colony forming units (CFU/mL) on all tested microbial groups (Gram-negative and Gram-positive bacteria, yeasts and molds). These results were supported by the live/dead assay. For further insights, the PPA-ingredients were detected with Fourier Transformation Infrared Spectroscopy (FTIR), which revealed NO2, NO and N2O5 as the main reactive species in the PPA. In the future, PPA could be an outstanding, on-demand sanitation step for higher food safety standards, especially in situations where humidity and high temperature should be avoided.

Towards the development of source separation and valorization of human excreta? Emerging dynamics and prospects in France

The source separation of human excreta (urine and/or feces) offers an alternative to conventional sanitation systems (flush toilets/public sewers) that is appealing in several respects, especially in environmental terms and for agricultural purposes, as a source of natural fertilizer from local and renewable resources. In France, systems for the separate collection of human excreta have previously been confined to the rural sphere and mainly implemented at the individual scale. However, since the 2010s, experimental projects in excreta source separation have been observed in urban areas, at the scale of individual houses and collective buildings, or even neighborhoods. This article, drawing on interdisciplinary social science research conducted within the French research program OCAPI (on ecological transition in nutrition/excretion systems), investigates these innovative projects for the source separation of human excreta in urban areas. Our work lies on a territorial approach, based on a cross-sectional analysis of experimental projects in three cities (Paris, Bordeaux and Grenoble), complemented by the mobilization of the “multi-level perspective” and the “technological innovation systems” frameworks. We study the trajectory and factors of development of source separation in France, its implementation dynamics and territorialisation pathways. Our analysis shows that source separation is still in an emerging phase in France. It is currently experimented in cities through diversified projects and approaches. This diversity applies both to socio-technical choices and territorial embeddedness’ forms. Adopting a prospective point of view, we then point out main obstacles and drivers to the scaling-up of this innovative practice: beyond technical issues, shared social values, stakeholder alignment issues and organizational challenges are essential. Finally, we consider possible directions for its development, ranging from the spread of a homogeneous solution to the continuation of a diversity of approaches on different territories.

Multidrug-Resistant Biofilms (MDR): Main Mechanisms of Tolerance and Resistance in the Food Supply Chain.

Biofilms are mono- or multispecies microbial communities enclosed in an extracellular matrix (EPS). They have high potential for dissemination and are difficult to remove. In addition, biofilms formed by multidrug-resistant strains (MDRs) are even more aggravated if we consider antimicrobial resistance (AMR) as an important public health issue. Quorum sensing (QS) and horizontal gene transfer (HGT) are mechanisms that significantly contribute to the recalcitrance (resistance and tolerance) of biofilms, making them more robust and resistant to conventional sanitation methods. These mechanisms coordinate different strategies involved in AMR, such as activation of a quiescent state of the cells, moderate increase in the expression of the efflux pump, decrease in the membrane potential, antimicrobial inactivation, and modification of the antimicrobial target and the architecture of the EPS matrix itself. There are few studies investigating the impact of the use of inhibitors on the mechanisms of recalcitrance and its impact on the microbiome. Therefore, more studies to elucidate the effect and applications of these methods in the food production chain and the possible combination with antimicrobials to establish new strategies to control MDR biofilms are needed.

HUBUNGAN PENGETAHUAN DENGAN MINAT DALAM PENGGUNAAN MENSTRUAL CUP PADA MAHASISWI UNIVERSITAS NASIONAL JAKARTA

Background: Menstrual cup is an internal device for menstrual flow and is claimed to be an environmentally friendly alternative to conventional menstrual sanitation protection. Women's knowledge about environmentally friendly menstrual cups is important for every woman's attention in the concept of menstrual hygiene and helps in realizing the Sustainable Development Goals (SDGs) in 2030. However, inappropriate knowledge makes menstrual cups less desirable. Aim: this study aimed to analyze the relationship between knowledge and interest in the use of menstrual cups. Methods: the method was a cross sectional approach. The sample in this study was 88 nursing students at the National University of Jakarta through accidental sampling technique. The variables analyzed were the level of knowledge and interest of female students. The research instrument used was a knowledge and interest questionnaire. Data were analyzed with Mann Whitney with p=0,05. Results: Respondents in this study had a good level of knowledge (54.6%) and had no interest in the use of menstrual cups (78.4%). Based on the results of the Mann Whitney test, the P value obtained is P = 0.120 > 0.05. Conclusion: There was no relationship between knowledge about menstrual cups and interest in using menstrual cups.Keywords : Menstrual Cup; Interest; Knowledge

Potential of lytic bacteriophages as disinfectant to control of Pseudomonas aeruginosa on fomites.

Nosocomial infections can be transmitted by contaminated hospital surfaces with resistant pathogens. Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic pathogen that causes public healthcare issues. Conventional sanitation is not efficiently contributing to removing resistant pathogens. Bacteriophages suggest safe and specific decontamination. Bacteriophages are a promising alternative strategy to chemical biocides. This research aimed to evaluate the potential of phage in controlling P. aeruginosa in infected hard surfaces. Bacteriophage was isolated from hospital wastewater. The efficiency lytic activity of phage against P. aeruginosa was assessed on various infected hard surfaces as plastic and ceramic. 50µl of the phage lysate (2 × 1012 PFU/mL) and 50µl of 70% Ethanol solution separately were spread on the different infected surfaces. After 15min, 1, 3, 6, and 24h, surfaces were directly sampled by contact plates. The bacterial load was evaluated by enumerating plate CFU. Cystoviridae phages with titer (2 × 1012 PFU/mL) efficiently can reduce P. aeruginosa on contaminated surfaces. The treated surfaces with 70% Ethanol solution and phage showed an evident drop in bacterial cell number. Bacteriophages can be used as a new option for the development of biological products aimed at the control and deletion of pathogens on contaminated hard surfaces.

To separate or not? A comparison of wastewater management systems for the new city district of Hiedanranta, Finland

In this study, life cycle assessment (LCA) and life cycle costing (LCC) methods were applied for the new city district of Hiedanranta, where source-separating sanitation systems are being considered. Two source-separating systems were compared to the conventional sanitation system with a centralized wastewater treatment plant (WWTP). With a separating system, three to 10 times more nitrogen could be recovered compared to the conventional system. If the nutrient potential of the reject water of the sludge digestion were to be utilized, the recovery rate would be even higher. For phosphorus, the recovered amount would be at the same level for all the alternatives. However, the plant availability of phosphorus is higher in separating systems. Based on the environmental impacts of separating systems with improved nutrient recovery, the climate and eutrophication impacts could be reduced, but the acidification impact may be higher. However, the actual climate benefits depend on how the avoided emissions will be realized, which is highly dependent on the policy and decision-making processes in the society. The life cycle costs of the alternative source-separating systems are higher at current prices. Source-separating sanitation produces new recycled nutrient products of human origin that contain fewer contaminants and could therefore be more easily accepted for end use when certain boundary conditions are met.

Is It Possible to Produce Certified Hazelnut Plant Material in Sicily? Identification and Recovery of Nebrodi Genetic Resources, in vitro Establishment, and Innovative Sanitation Technique From Apple Mosaic Virus.

Eight Sicilian cultivars of hazelnut (Corylus avellana L.), namely-Curcia, Nociara Collica, Panottara Collica, Panottara Galati Grande, Parrinara, Panottara Baratta Piccola, Enzo, and Rossa Galvagno, registered into the Italian Cultivar Register of fruit tree species in 2017 were selected from Nebrodi area and established in vitro. The aim of the work was to carry out the sanitation of the cultivars and get virus-free plants from the most important viral pathogen threat, the apple mosaic virus. Virus-free plant material is essential for the production of certified plants from Sicilian hazelnut cultivars, complying the CE (cat. CAC) quality and the technical standards established in 2017 for voluntary certification by the Italian Ministry of Agricultural, Food and Forestry Policies (MIPAAF). In this study, we investigated the possibility of establishing in vitro true-to-type and virus-free hazelnut plantlets via the encapsulation technology of apexes. The in vitro shoot proliferation rates were assessed for the different cultivars, sampling periods, temperature treatments, and type of explant used for culture initiation. Viability, regrowth, and conversion rates of both conventional meristem tip culture (MTC) and not conventional (MTC combined with the encapsulation technology) sanitation techniques were evaluated.

Re-emergence of dry toilets and fecal nutrient reuse in M'zab cities

Abstract In the M'zab valley, dry toilets represent an ancestral dry sanitation system, serving as a source of fertilizer thanks to human excrement valorization. However, in the 20th century, local populations began to shun these systems. The objective of this article is to illustrate the importance of dry toilets on agricultural and environmental scales in ancient M'Zab, and the renewal of these systems in response to sanitation problems in the oasis after their decline. The hypothesis put forward is that dry toilets can act as a complementary system to conventional sanitation systems. Data were collected through interviews with the local population. Our results show that the use of dry toilets, and the resulting use of human excrement as fertilizer, has gone through three phases. First, a phase of strong recycling dynamics, followed by a second phase of decline in dry toilet use which is linked to the discovery of the Albian aquifer and flush toilet adoption. The third phase is characterized by dry toilet reuse in response to oasis degradation caused by sanitation and environmental problems. Some oasesians have taken the initiative to revert to dry toilets to ensure oasis system sustainability and to revive the practice of recycling human waste.

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).

An integrated assessment of environmental, economic, social and technological parameters of source separated and conventional sanitation concepts: A contribution to sustainability analysis

Resource recovery and reuse from domestic wastewater has become an important subject for the current development of sanitation technologies and infrastructures. Different technologies are available and combined into sanitation concepts, with different performances. This study provides a methodological approach to evaluate the sustainability of these sanitation concepts with focus on resource recovery and reuse. St. Eustatius, a small tropical island in the Caribbean, was used as a case study for the evaluation. Three source separation-community-on-site and two combined sewerage island-scale concepts were selected and compared in terms of environmental (net energy use, nutrient recovery/reuse, BOD/COD, pathogens, and GHG emission, land use), economic (CAPEX and OPEX), social cultural (acceptance, required competences and education), and technological (flexibility/adaptability, reliability/continuity of service) indicators. The best performing concept, is the application of Upflow Anaerobic Sludge Bed (UASB) and Trickling Filter (TF) at island level for combined domestic wastewater treatment with subsequent reuse in agriculture. Its overall average normalised score across the four categories (i.e., average of average per category) is about 15% (0.85) higher than the values of the remaining systems and with a score of 0.73 (conventional activated sludge – centralised level), 0.77 (UASB-septic tank (ST)), 0.76 (UASB-TF - community level), and 0.75 (ST - household level). The higher score of the UASB-TF at community level is mainly due to much better performance in the environmental and economic categories. In conclusion, the case study provides a methodological approach that can support urban planning and decision-making in selecting more sustainable sanitation concepts, allowing resource recovery and reuse in small island context or in other contexts.

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

Abstract 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.

The improved and the unimproved: Factors influencing sanitation and diarrhoea in a peri-urban settlement of Lusaka, Zambia.

Accounting for peri-urban sanitation poses a unique challenge due to its high density, unplanned stature, with limited space and funding for conventional sanitation instalment. To better understand users, needs and inform peri-urban sanitation policy, our study used multivariate stepwise logistic regression to assess the factors associated with use of improved (toilet) and unimproved (chamber) sanitation facilities among peri-urban residents. We analysed data from 205 household heads in 1 peri-urban settlement of Lusaka, Zambia on socio-demographics (economic status, education level, marital status, etc.), household sanitation characteristics (toilet facility, ownership and management) and household diarrhoea prevalence. Household water, sanitation and hygiene (WASH) facilities were assessed based on WHO-UNICEF criteria. Of particular interest was the simultaneous use of toilet facilities and chambers, an alternative form of unimproved sanitation with focus towards all-in-one suitable alternatives. Findings revealed that having a regular income, private toilet facility, improved drinking water and handwashing facility were all positively correlated to having an improved toilet facility. Interestingly, both improved toilets and chambers indicated increased odds for diarrhoea prevalence. Odds of chamber usage were also higher for females and users of unimproved toilet facilities. Moreover, when toilets were owned by residents, and hygiene was managed externally, use of chambers was more likely. Findings finally revealed higher diarrhoea prevalence for toilets with more users. Results highlight the need for a holistic, simultaneous approach to WASH for overall success in sanitation. To better access and increase peri-urban sanitation, this study recommends a separate sanitation ladder for high density areas which considers improved private and shared facilities, toilet management and all-inclusive usage (cancelling unimproved alternatives). It further calls for financial plans supporting urban poor access to basic sanitation and increased education on toilet facility models, hygiene, management and risk to help with choice and proper facility use to maximize toilet use benefit.

A comparison of different scenarios for on-site reuse of blackwater and kitchen waste using the life cycle assessment methodology

Decentralized systems for treatment of domestic effluents have been suggested as a sustainable alternative for situations where conventional sanitation has not yet been established. This study compares three possible scenarios for the destination of separated blackwater (BW) and kitchen waste (KW), being: co-digestion of both (BW&KW) in loco with subsequent reuse of sub-products like nutrients and water (scenario 1); discharge of BW into a septic-tank and composting of the KW (scenario 2) and discharge of the BW into a septic-tank and of the KW at a solid waste disposal (scenario 3, actually the most common situation in large part of Brazil). In order to compare the scenarios, the use of equivalent amounts of water and fertilizer was considered in scenarios 2 (septic-tank and composting) and 3 (septic-tank and landfill), in order to maintain functional equivalence with that of scenario 1 (co-digestion and reuse). In scenario 1, treatment of the organic waste in an Upflow Anaerobic Sludge Blanket (UASB) reactor, for a period of 6 (scenario 1A) or 12 days (scenario 1B), with effluent recycling, was considered. In order to verify the effect of the use of energy in scenario 1 and to verify the effect of the degree of treatment realized in scenarios 2 and 3, a sensitivity analysis was realized for the parameters energy use and COD removal. The management of the sub-products in scenario 1 resulted in emission gains, when compared to scenarios 2 and 3, where the need to include amounts of water and fertilizer, to obtain functional equivalence, increased the environmental impacts associated to these scenarios. However the energy consumption increased the impact levels in scenario 1 and, overall, scenario 2 (septic-tank and composting), obtained the lowest impact scores, presenting the most advantageous scenario, among the three scenarios studied, from an environmental point of view, considering the restrictions as defined here, followed by scenarios 3 (septic-tank and landfill), 1A (6-day co-digestion and reuse) and 1B (12-day co-digestion and reuse). After the sensitivity analysis the influence of energy consumption on the impact categories for scenario 1 became evident, whereas, on the other hand, the degree of pollution removal from the blackwater did not change the overall results, making thus minimizing energy consumption during treatment more relevant than improving pollutant removal, in order to minimize the environmental impacts.

Value Adding Innovations in Sanitation

Conventional sanitation based on long transport of wastewater in sewage and multistage wastewater treatment prevents health and environmental impacts but it is costly. Two innovations in sanitation, which comply with high health and environmental standards and reduce costs are presented. A social innovation led by a farmers’ association reuses effluent on a regional scale. After municipal wastewater treatment effluents are transported to reservoirs for additional biodegradation and reuse for irrigation. About 30% of the annual costs are saved compared to the conventional sanitation but regulations and organizational challenges impede dissemination of this systems. A technological innovation led by social entrepreneurs and non-governmental organizations refers to the decentralized sanitation with biodigesters and constructed wetlands. A vertical flow helophyte system, certified for the highest health and environmental standards, is used for sanitation of a few million person equivalents in households, services and industries. The costs are reduced by 40% compared to the conventional sanitation and can be beneficial when scale is large and co-benefits are attained but they need much space. The innovative citizen’s initiatives can be encouraged given low institutional interest for innovative sanitation.

Could we fight healthcare-associated infections and antimicrobial resistance with probiotic-based sanitation? Commentary.

Healthcare-associated infections (HAI) affect every year about 4 million hospitalized patients in the EU, causing over 33 000 deaths as a direct consequence and over 1.1 billion € associated costs. Besides the persistent microbial contamination of the hospital environment, a major cause is the rampant antimicrobial resistance (AMR) of the HAI-associated pathogens. The hospital environment itself is in fact a reservoir of resistant pathogens, apparently not sufficiently controlled by conventional chemical-based sanitation. A recently published study, the SAN-ICA study, performed in Italy, suggests that the fight against AMR may involve probiotic-based sanitation approaches, as they might stably reduce AMR surface pathogens, finally reducing HAI incidence. Here we discuss the reported results and argue that their use may provide a novel approach which deserves exploration.

Sanitation game changing: paradigm shift from end-of-pipe to off-grid solutions

Abstract The toilet-wastewater-pollution nexus – the provision of safe, hygienic and appropriate sanitation solutions – is an emerging, priority issue world-wide. Developed nations have followed a linear design approach to achieve their sanitation needs, with conventional waterborne systems continuously improved to meet more stringent control and pollution regulations while minimising the load on the natural environment. Developing countries, on the other hand, continue to struggle to implement such systems, due to a myriad of factors associated with financing, affordability and revenue, and thus rely heavily on on-site systems. On-site systems pose a different set of technical challenges related to their management, which is often overlooked in the developing world. Whereas, while technology strides increase in conventional sanitation processes towards zero-effluent, these come at a significant cost and energy requirement. Further, climate variability and water security put added pressure on the resources available for flushing and transporting human waste. A new paradigm for sanitation, proposed in this paper, introduces and is based on technology disrupters that can safely treat human excreta, and matches user preferences without the need for sewers, or reliance on large quantities of water and/or energy supplies. Through innovation and smart-chain supply, universal access can be achieved sustainably, and linked to water security and business opportunities. The opportunity arises for leapfrogging these solutions in growing cities in the developing world, reducing water consumption and eliminating pollutant pathways.