Enhancing the nitrogen and phosphorus content of faecal-derived biochar via adsorption and precipitation from human urine.

Urine diversion in toilets is a promising strategy to maximise nutrient recovery and produce low-cost urine-derived fertilisers. There are various methods for nutrient recovery from urine, including precipitation and adsorption onto porous media, such as biochars. This study uses faecal-derived biochars to produce and, for the first time, comprehensively characterise enriched biochar fertilisers with the addition of fully hydrolysed undiluted human urine. The evolution of urea hydrolysis and nutrient content during urine storage was initially investigated over a 6-month storage period and NH4+ adsorption mechanisms studied under varying biochar doses and NH4-N concentrations. The process was further optimised by adding MgO to induce precipitation reactions, enabling the combined recovery of NH4+ and P. For NH4+ adsorption, experimental data exhibited a good fit to both the Freundlich (R2 = 0.989) and Langmuir (R2 = 0.974) isotherm models and the rate of the reaction was well described by a pseudo 2nd order kinetics model (R2 = 0.988). The NH4+ uptake was rapid during the initial 2 h of the reaction and the adsorption process reached completion after 24 h. The NH4-N adsorption capacity of the faecal-derived biochar was 19.8 mg/g and the main adsorption mechanism identified was ion exchange (K+ ↔ NH4+), as confirmed by XRD and ICP-OES. The effect of different biochar doses (0, 25, 50, 100 g/L) and MgO addition scenarios (Mg:P = 0, 1.5, 4) on N and P recovery showed that the combination of MgO (Mg:P = 1.5) with the lower biochar dose (25 g/L) produced the most NP-rich fertiliser product which was easily separated from the urine. Faecal-derived biochar had a limited adsorption capacity for P, with precipitation being the main mechanism for P recovery. When MgO was added to urine, >98% of total P was recovered via precipitation of struvite/struvite-K and substituted hydroxyapatite, as identified via SEM-EDX. Faecal-derived biochar was a successful carrier to recover the P-containing precipitates and facilitate liquid-solid separation after treatment. The findings of this study provide proof-of concept for the systemic management of source separated human excreta and pave the way for the production of marketable waste-derived fertilisers from on-site sanitation systems.

Source separation of human excreta: Effect on resource recovery via pyrolysis.

More people globally are now using on-site sanitation technologies than sewered connections. The management of faecal sludge generated by on-site facilities is still challenging and requires an understanding of all sanitation service chain components and their interactions; from source conditions to treatment and resource recovery. This study aimed to improve the current lack of knowledge regarding these interactions, by establishing a quantifiable relationship between human excreta source separation and resource recovery via pyrolysis. The effects of source separation of faeces and urine on biochar quality were investigated for different pyrolysis temperatures (450 °C, 550 °C, 650 °C) and this information was used to assess energy and nutrient recovery. Results quantify the benefits of urine diversion for nitrogen recovery (70% of total N losses during thermal treatment avoided) and show an increase in the liming potential of the produced faecal-based biochars. The quality of produced solid fuels is also improved when source-separated faeces (SSF) are used as a feedstock for pyrolysis, including a 50% increase in char calorific value. On the other hand, biochars from mixed urine and faeces (MUF) are more rich in phosphorus and potassium, and surface morphology investigation indicates higher porosity compared to SSF biochars. The high salinity of MUF biochars should be considered before agricultural applications. For both biochar types (SSF, MUF), the presence of phosphate compounds of high fertiliser value was confirmed by X-ray diffraction analysis, and temperatures around 500 °C are recommended to optimise nutrient and carbon behaviour when pyrolysing human excreta. These findings can be used for the design of circular faecal sludge management systems, linking resource recovery objectives to source conditions, and vice-versa. Ultimately, achieving consistent resource recovery from human excreta can act as an incentive for universal access to safe and sustainable sanitation.

The efficacy of soap against schistosome cercariae: A systematic review.

BACKGROUND: Schistosomiasis is a parasitic disease that is endemic in 78 countries and affects almost 240 million people worldwide. It has been acknowledged that an integrated approach that goes beyond drug treatment is needed to achieve control and eventual elimination of the disease. Improving hygiene has been encouraged by World Health Organisation, and one aspect of good hygiene is using soap during water-contact activities, such as bathing and doing laundry. This hygiene practice might directly reduce the skin exposure to cercariae at transmission sites. A systematic review was carried out to investigate the efficacy of soap against schistosome cercariae and to identify the knowledge gaps surrounding this topic. METHODOLOGY: Six online databases were searched between 5th and 8th July of 2021. Records returned from these databases were screened to remove duplicates, and the remaining records were classified by reading titles, abstracts, and full texts to identify the included studies. The results were categorised into two groups based on two different protective mechanisms of soap (namely, damage to cercariae and protection of skin). CONCLUSIONS: Limited research has been conducted on the efficacy of soap against schistosome cercariae and only 11 studies met the criteria to be included in this review. The review demonstrates that soap has the potential of protecting people against schistosome cercariae and there are two protective aspects: (1) soap affects cercariae adversely; (2) soap on the skin prevents cercariae from penetrating the skin, developing into adult worms and producing eggs. Both aspects of protection were influenced by many factors, but the differences in the reported experimental conditions, such as the cercarial endpoint measurement used and the cercaria numbers used per water sample, lead to low comparability between the previous studies. This review indicates that more evidence is needed to inform hygiene advice for people living in schistosomiasis endemic areas.

A novel theatre-based behaviour change approach for influencing community uptake of schistosomiasis control measures.

BACKGROUND: Appropriate behaviour change with regard to safe water contact practices will facilitate the elimination of schistosomiasis as a public health concern. Various approaches to effecting this change have been trialled in the field but with limited sustainable outcomes. Our case study assessed the effectiveness of a novel theatre-based behaviour change technique (BCT), in combination with cohort awareness raising and capacity training intervention workshops. METHODOLOGY: Our study was carried out in four rural communities in the Mwanza region of Tanzania and in the semi-urban town of Kemise, Ethiopia. We adapted the Risk, Attitude, Norms, Ability and Self-regulation (RANAS) framework and four phases using a mixed methods approach. Participatory project phase engagement and qualitative formative data were used to guide the design of an acceptable, holistic intervention. Initial baseline (BL) data were collected using quantitative questionnaire surveys with 804 participants in Tanzania and 617 in Ethiopia, followed by the theatre-based BCT and capacity training intervention workshops. A post-intervention (PI) survey was carried out after 6 months, with a participant return rate of 65% in Tanzania and 60% in Ethiopia. RESULTS: The intervention achieved a significant improvement in the knowledge of schistosomiasis transmission being associated with poorly managed sanitation and risky water contact. Participants in Tanzania increased their uptake of preventive chemotherapy (males: BL, 56%; PI, 73%, females: BL, 43%; PI, 50%). There was a significant increase in the selection of sanitation (Tanzania: BL, 13%; PI, 21%, Ethiopia: BL, 63%; PI, 90%), safe water and avoiding/minimising contact with infested waters as prevention methods in Tanzania and Ethiopia. Some of the participants in Tanzania followed on from the study by building their own latrines. CONCLUSIONS: This study showed that substantial positive behaviour changes in schistosomiasis control can be achieved using theatre-based BCT intervention and disease awareness training. With the appropriate sensitisation, education and stakeholder engagement approaches, community members were more open to minimising risk-associated contact with contaminated water sources and were mobilised to implement preventive measures.

Spatial heterogeneity in drinking water sources in the Greater Accra Metropolitan Area (GAMA), Ghana.

Universal access to safe drinking water is essential to population health and well-being, as recognized in the Sustainable Development Goals (SDG). To develop targeted policies which improve urban access to improved water and ensure equity, there is the need to understand the spatial heterogeneity in drinking water sources and the factors underlying these patterns. Using the Shannon Entropy Index and the Index of Concentration at the Extremes at the enumeration area level, we analyzed census data to examine the spatial heterogeneity in drinking water sources and neighborhood income in the Greater Accra Metropolitan Area (GAMA), the largest urban agglomeration in Ghana. GAMA has been a laboratory for studying urban growth, economic security, and other concomitant socio-environmental and demographic issues in the recent past. The current study adds to this literature by telling a different story about the spatial heterogeneity of GAMA's water landscape at the enumeration area level. The findings of the study reveal considerable geographical heterogeneity and inequality in drinking water sources not evidenced in previous studies. We conclude that heterogeneity is neither good nor bad in GAMA judging by the dominance of both piped water sources and sachet water (machine-sealed 500-ml plastic bag of drinking water). The lessons from this study can be used to inform the planning of appropriate localized solutions targeted at providing piped water sources in neighborhoods lacking these services and to monitor progress in achieving universal access to improved drinking water as recognized in the SDG 6 and improving population health and well-being.

Specific Nucleic AcId Ligation for the detection of Schistosomes: SNAILS.

Schistosomiasis, also known as bilharzia or snail fever, is a debilitating neglected tropical disease (NTD), caused by parasitic trematode flatworms of the genus Schistosoma, that has an annual mortality rate of 280,000 people in sub-Saharan Africa alone. Schistosomiasis is transmitted via contact with water bodies that are home to the intermediate host snail which shed the infective cercariae into the water. Schistosome lifecycles are complex, and while not all schistosome species cause human disease, endemic regions also typically feature animal-infecting schistosomes that can have broader economic and/or food security implications. Therefore, the development of species-specific Schistosoma detection technologies may help to inform evidence-based local environmental, food security and health systems policy making. Crucially, schistosomiasis disproportionally affects low- and middle-income (LMIC) countries and for that reason, environmental screening of water bodies for schistosomes may aid with the targeting of water, sanitation, and hygiene (WASH) interventions and preventive chemotherapy to regions at highest risk of schistosomiasis transmission, and to monitor the effectiveness of such interventions at reducing the risk over time. To this end, we developed a DNA-based biosensor termed Specific Nucleic AcId Ligation for the detection of Schistosomes or 'SNAILS'. Here we show that 'SNAILS' enables species-specific detection from genomic DNA (gDNA) samples that were collected from the field in endemic areas.

Sachet water in Ghana: A spatiotemporal analysis of the recent upward trend in consumption and its relationship with changing household characteristics, 2010-2017.

The consumption of packaged water in Ghana has grown significantly in recent years. By 2017, "sachet water"-machine-sealed 500ml plastic bags of drinking water-was consumed by 33% of Ghanaian households. Reliance on sachet water has previously been associated with the urban poor, yet recent evidence suggests a customer base which crosses socioeconomic lines. Here, we conduct a repeated cross-sectional analysis of three nationally representative datasets to examine the changing demography of sachet water consumers between 2010 and 2017. Our results show that over the course of the study period sachet water has become a ubiquitous source of drinking water in Ghana, with relatively wealthy households notably increasing their consumption. In 2017, the majority of sachet water drinking households had access to another improved water source. The current rate and form of urbanisation, inadequate water governance, and an emphasis on cost recovery pose significant challenges for the expansion of the piped water supply network, leading us to conclude that sachet water will likely continue to be a prominent source of drinking water in Ghana for the foreseeable future. The main challenge for policymakers is to ensure that the growing sachet water market enhances rather than undermines Ghana's efforts towards achieving universal and equitable access to clean drinking water and sanitation.

The rate of vermi-compost accumulation within 'Tiger Toilets' in India.

Tiger Toilets use a worm-based ecosystem to degrade human waste and have recently been demonstrated as a cost-effective innovation in on-site sanitation. The benefits over traditional pit latrines include slower fill rate, fewer odours, and safer emptying. However, a question remains around how to measure the rate of accumulation of vermi-compost and predict the fill rate into the future. In this study, fifteen Tiger Toilets of varying installation ages in the villages of Jejuri, Bhalgudi and Walhe/Adachiwadi, in Maharashtra province, India were investigated to determine the rate of filling. A laser measure was used to define cross-sections of the depth to vermi-compost layers within the Tiger Toilet digesters. Bench-scale column tests were used to estimate liquid infiltration rates from the digesters into the surrounding soils. Changes over time in the interior digester conditions were photographed and a video camera was installed in selected digesters to confirm and observe the worm activity in situ under red light. Calculated fill rates of the Tiger Toilets were significantly lower compared to estimated fill rates of traditional pit latrines of a similar size and usage rate. The infiltration of the liquid fraction of the waste into the surrounding soil was observed to be a key factor in filling.

Faecal sludge pyrolysis: Understanding the relationships between organic composition and thermal decomposition.

Sludge treatment is an integral part of faecal sludge management in non-sewered sanitation settings. Development of pyrolysis as a suitable sludge treatment method requires thorough knowledge about the properties and thermal decomposition mechanisms of the feedstock. This study aimed to improve the current lack of understanding concerning relevant sludge properties and their influence on the thermal decomposition characteristics. Major organic compounds (hemicellulose, cellulose, lignin, protein, oil and grease, other carbohydrates) were quantified in 30 faecal sludge samples taken from different sanitation technologies, providing the most comprehensive organic faecal sludge data set to date. This information was used to predict the sludge properties crucial to pyrolysis (calorific value, fixed carbon, volatile matter, carbon, hydrogen). Samples were then subjected to thermogravimetric analysis to delineate the influence of organic composition on thermal decomposition. Septic tanks showed lower median fractions of lignin (9.4%dwb) but higher oil and grease (10.7%dwb), compared with ventilated improved pit latrines (17.4%dwb and 4.6%dwb respectively) and urine diverting dry toilets (17.9%dwb and 4.7%dwb respectively). High fixed carbon fractions in lignin (45.1%dwb) and protein (18.8%dwb) suggested their importance for char formation, while oil and grease fully volatilised. For the first time, this study provided mechanistic insights into faecal sludge pyrolysis as a function of temperature and feedstock composition. Classification into the following three phases was proposed: decomposition of hemicellulose, cellulose, other carbohydrates, proteins and, partially, lignin (200-380 °C), continued decomposition of lignin and thermal cracking of oil and grease (380-500 °C) and continued carbonisation (>500 °C). The findings will facilitate the development and optimisation of faecal sludge pyrolysis, emphasising the importance of considering the organic composition of the feedstock.

Ultraviolet disinfection of Schistosoma mansoni cercariae in water.

BACKGROUND: Schistosomiasis is a parasitic disease that is transmitted by skin contact with waterborne schistosome cercariae. Mass drug administration with praziquantel is an effective control method, but it cannot prevent reinfection if contact with cercariae infested water continues. Providing safe water for contact activities such as laundry and bathing can help to reduce transmission. In this study we examine the direct effect of UV light on Schistosoma mansoni cercariae using ultraviolet light-emitting diodes (UV LEDs) and a low-pressure (LP) mercury arc discharge lamp. METHODOLOGY: S. mansoni cercariae were exposed to UV light at four peak wavelengths: 255 nm, 265 nm, 285 nm (UV LEDs), and 253.7 nm (LP lamp) using bench scale collimated beam apparatus. The UV fluence ranged from 0-300 mJ/cm2 at each wavelength. Cercariae were studied under a stereo-microscope at 0, 60, and 180 minutes post-exposure and the viability of cercariae was determined by assessing their motility and morphology. CONCLUSION: Very high UV fluences were required to kill S. mansoni cercariae, when compared to most other waterborne pathogens. At 265 nm a fluence of 247 mJ/cm2 (95% confidence interval (CI): 234-261 mJ/cm2) was required to achieve a 1-log10 reduction at 0 minutes post-exposure. Cercariae were visibly damaged at lower fluences, and the log reduction increased with time post-exposure at all wavelengths. Fluences of 127 mJ/cm2 (95% CI: 111-146 mJ/cm2) and 99 mJ/cm2 (95% CI: 85-113 mJ/cm2) were required to achieve a 1-log10 reduction at 60 and 180 minutes post-exposure at 265 nm. At 0 minutes post-exposure 285 nm was slightly less effective, but there was no statistical difference between 265 nm and 285 nm after 60 minutes. The least effective wavelengths were 255 nm and 253.7 nm. Due to the high fluences required, UV disinfection is unlikely to be an energy- or cost-efficient water treatment method against schistosome cercariae when compared to other methods such as chlorination, unless it can be demonstrated that UV-damaged cercariae are non-infective using alternative assay methods or there are improvements in UV LED technology.

Critical analytical parameters for faecal sludge characterisation informing the application of thermal treatment processes.

Thermal processes for the treatment of faecal sludge such as pyrolysis or combustion offer complete destruction of pathogens, whilst allowing for energy and nutrient recovery. The development of such processes is currently constrained by a lack of knowledge on thermally relevant faecal sludge characteristics. This study investigated thirty faecal sludge samples from three sanitation technologies (ventilated improved pit latrines (VIP), urine diverting dry toilets (UD), septic tanks (ST)) and compared these by non-parametric statistical analysis. A focus was placed on parameters necessary for thermal process development and recoverable nutrient concentrations. The relevant characteristics ranged widely within technology groups. Calorific values and ash concentrations of 2.1-25.7 MJ/kg and 9.5-88.4% were observed for STs, of 9.2-13.9 MJ/kg and 40.9-61.5% for VIPs and of 3.9-18.1 MJ/kg and 18.8-81.3% for UDs. These two parameters show a strong linear inverse correlation and determine the minimum dewatering requirements from which a net energy recovery may be possible. Results suggest that more than 90% of samples can meet these requirements following commonly used dewatering technologies. A comparison across technologies provided strong evidence that the faecal sludge source significantly influences sludge composition, emphasized by higher median ratios of fixed carbon to volatile matter in VIPs (0.23) and UDs (0.23) compared to STs (0.15). The sanitation technology also influenced recoverable nutrient concentrations, with phosphorus and potassium concentrations generally ranging between 5.8-49.2 g/kg and 1.4-26.1 g/kg respectively. Compared to STs, median concentrations of phosphorus and potassium in VIPs were 3.4 and 3.8 times higher respectively, and 3.0 and 8.8 times higher in UDs. The findings highlight the importance of considering the faecal sludge source in the development of thermal treatment processes. This study provides critical knowledge to further develop such processes through modelling, experimental and scaled approaches.

Modeling the Impacts of Urban Flood Risk Management on Social Inequality.

The exposure of urban populations to flooding is highly heterogeneous, with the negative impacts of flooding experienced disproportionately by the poor. In developing countries experiencing rapid urbanization and population growth a key distinction in the urban landscape is between planned development and unplanned, informal development, which often occurs on marginal, flood-prone land. Flood risk management in the context of informality is challenging, and may exacerbate existing social inequalities and entrench poverty. Here, we adapt an existing socio-hydrological model of human-flood interactions to account for a stratified urban society consisting of planned and informal settlements. In the first instance, we use the model to construct four system archetypes based on idealized scenarios of risk reduction and disaster recovery. We then perform a sensitivity analysis to examine the relative importance of the differential values of vulnerability, risk-aversion, and flood awareness in determining the relationship between flood risk management and social inequality. The model results suggest that reducing the vulnerability of informal communities to flooding plays an important role in reducing social inequality and enabling sustainable economic growth, even when the exposure to the flood hazard remains high. Conversely, our model shows that increasing risk aversion may accelerate the decline of informal communities by suppressing economic growth. On this basis, we argue for urban flood risk management which is rooted in pro-poor urban governance and planning agendas which recognize the legitimacy and permanence of informal communities in cities.

Chlorination of Schistosoma mansoni cercariae.

BACKGROUND: Schistosomiasis is a water-based disease acquired through contact with cercaria-infested water. Communities living in endemic regions often rely on parasite-contaminated freshwater bodies for their daily water contact activities, resulting in recurring schistosomiasis infection. In such instances, water treatment can provide safe water on a household or community scale. However, to-date there are no water treatment guidelines that provide information on how to treat water containing schistosome cercariae. Here, we rigorously test the effectiveness of chlorine against Schistosoma mansoni cercariae. METHOD: S. mansoni cercariae were chlorinated using sodium hypochlorite under lab and field condition. The water pH was controlled at 6.5, 7.0 or 7.5, the water temperature at 20°C or 27°C, and the chlorine dose at 1, 2 or 3 mg/l. Experiments were conducted up to contact times of 45 minutes. 100 cercariae were used per experiment, thereby achieving up to 2-log10 inactivations of cercariae. Experiments were replicated under field conditions at Lake Victoria, Tanzania. CONCLUSION: A CT (residual chlorine concentration x chlorine contact time) value of 26±4 mg·min/l is required to achieve a 2-log10 inactivation of S. mansoni cercariae under the most conservative condition tested (pH 7.5, 20°C). Field and lab-cultivated cercariae show similar chlorine sensitivities. A CT value of 30 mg·min/l is therefore recommended to disinfect cercaria-infested water, though safety factors may be required, depending on water quality and operating conditions. This CT value can be achieved with a chlorine residual of 1 mg/l after a contact time of 30 minutes, for example. This recommendation can be used to provide safe water for household and recreational water activities in communities that lack safe alternative water sources.

Determining the viability of Schistosoma mansoni cercariae using fluorescence assays: An application for water treatment.

BACKGROUND: Schistosome cercariae are the human-infectious stage of the Schistosoma parasite. They are shed by snail intermediate hosts living in freshwater, and penetrate the skin of the human host to develop into schistosomes, resulting in schistosomiasis infection. Water treatment (e.g. filtration or chlorination) is one way of cutting disease transmission; it kills or removes cercariae to provide safe water for people to use for activities such as bathing or laundry as an alternative to infested lakes or rivers. At present, there is no standard method for assessing the effectiveness of water treatment processes on cercariae. Examining cercarial movement under a microscope is the most common method, yet it is subjective and time-consuming. Hence, there is a need to develop and verify accurate, high-throughput assays for quantifying cercarial viability. METHOD: We tested two fluorescence assays for their ability to accurately determine cercarial viability in water samples, using S. mansoni cercariae released from infected snails in the Schistosomiasis Collection at the Natural History Museum, London. These assays consist of dual stains, namely a vital and non-vital dye; fluorescein diacetate (FDA) and Hoechst, and FDA and Propidium Iodide. We also compared the results of the fluorescence assays to the viability determined by microscopy. CONCLUSION: Both fluorescence assays can detect the viability of cercariae to an accuracy of at least 92.2% ± 6.3%. Comparing the assays to microscopy, no statistically significant difference was found between the method's viability results. However, the fluorescence assays are less subjective and less time-consuming than microscopy, and therefore present a promising method for quantifying the viability of schistosome cercariae in water samples.

The formation of disinfection by-products from the chlorination and chloramination of amides.

This study examined the potential of six aliphatic and aromatic amides, commonly found in natural waters or used as chemical aids in water treatment, to act as organic precursors for nine haloacetamides (HAcAms), five haloacetonitriles (HANs), regulated trihalomethanes (THMs) and haloacetic acids (HAAs) upon chlorination and chloramination. The impact of key experimental conditions, representative of drinking water, including pH (7 & 8), retention time (4 & 24 h) and bromide levels (0 & 100 µg/L), on the generation of the target DBPs was investigated. The highest aggregate DBP yields upon chlor(am)ination were reported for the aromatic and hydrophobic hydroxybenzamide; 2.7% ± 0.1% M/M (chlorination) and 1.7% M/M (chloramination). Increased reactivity was observed in aliphatic and hydrophilic compounds, acrylamide (2.5 ± 0.2% M/M) and acetamide (1.3 ± 0.2% M/M), in chlorination and chloramination, respectively. The addition of bromide increased average DBP yields by 50-70%. Relative to chlorination, the application of chloramines reduced DBP formation by 66.5% (without Br-) and by 46.4% (with Br-). However, bromine incorporation in HAAs and HAcAms was enhanced following chloramination, of concern due to the higher toxicological potency of brominated compounds.

Resource recovery and biochar characteristics from full-scale faecal sludge treatment and co-treatment with agricultural waste.

Unsafe disposal of faecal sludge from onsite sanitation in low-income countries has detrimental effects on public health and the environment. The production of biochar from faecal sludge offers complete destruction of pathogens and a value-added treatment product. To date, research has been limited to the laboratory. This study evaluates the biochars produced from the co-treatment of faecal sludge from septic tanks and agricultural waste at two full-scale treatment plants in India by determining their physical and chemical properties to establish their potential applications. The process yielded macroporous, powdery biochars that can be utilised for soil amendment or energy recovery. Average calorific values reaching 14.9 MJ/kg suggest use as solid fuel, but are limited by a high ash content. Phosphorus and potassium are enriched in the biochar but their concentrations are restricted by the nutrient-depleted nature of septic tank faecal sludge. High concentrations of calcium and magnesium led to a liming potential of up to 20.1% calcium carbonate equivalents, indicating suitability for use on acidic soils. Heavy metals present in faecal sludge were concentrated in the biochar and compliance for soil application will depend on local regulations. Nevertheless, heavy metal mobility was considerably reduced, especially for Cu and Zn, by 51.2-65.2% and 48.6-59.6% respectively. Co-treatment of faecal sludge with other carbon-rich waste streams can be used to influence desired biochar properties. In this case, the addition of agricultural waste increased nutrient and fixed carbon concentrations, as well as providing an additional source of energy. This study is a proof of concept for biochar production achieving full-scale faecal sludge treatment. The findings will help inform appropriate use of the treatment products as this technology becomes more commonly applied.

In transition: current health challenges and priorities in Sudan.

A recent symposium and workshop in Khartoum, the capital of the Republic of Sudan, brought together broad expertise from three universities to address the current burden of communicable and non-communicable diseases facing the Sudanese healthcare system. These meetings identified common challenges that impact the burden of diseases in the country, most notably gaps in data and infrastructure which are essential to inform and deliver effective interventions. Non-communicable diseases, including obesity, type 2 diabetes, renal disease and cancer are increasing dramatically, contributing to multimorbidity. At the same time, progress against communicable diseases has been slow, and the burden of chronic and endemic infections remains considerable, with parasitic diseases (such as malaria, leishmaniasis and schistosomiasis) causing substantial morbidity and mortality. Antimicrobial resistance has become a major threat throughout the healthcare system, with an emerging impact on maternal, neonatal and paediatric populations. Meanwhile, malnutrition, micronutrient deficiency and poor perinatal outcomes remain common and contribute to a lifelong burden of disease. These challenges echo the United Nations (UN) sustainable development goals and concentrating on them in a unified strategy will be necessary to address the national burden of disease. At a time when the country is going through societal and political transition, we draw focus on the country and the need for resolution of its healthcare needs.

Ultraviolet sensitivity of WASH (water, sanitation, and hygiene) -related helminths: A systematic review.

BACKGROUND: Helminthiases are a group of disabling neglected tropical diseases that affect billions of people worldwide. Current control methods use preventative chemotherapy but reinfection is common and an inter-sectoral approach is required if elimination is to be achieved. Household and community scale water treatment can be used to provide a safe alternative water supply for contact activities, reducing exposure to WASH (water, sanitation, and hygiene) -related helminths. With the introduction of ultraviolet light emitting diodes (UV-C LEDs), ultraviolet (UV) disinfection could be a realistic option for water treatment in low-income regions in the near future, to provide safe alternative water supplies for drinking and contact activities such as handwashing, bathing, and laundry, but currently there is no guidance for the use of UV or solar disinfection against helminths. METHODOLOGY: A qualitative systematic review of existing literature was carried out to establish which WASH-related helminths are more susceptible to UV disinfection and identify gaps in research to inform future studies. The search included all species that can infect humans and can be transmitted through water or wastewater. Five online databases were searched and results were categorized based on the UV source: sunlight and solar simulators, UV-A and UV-B (long wavelength) sources, and UV-C (germicidal) sources. CONCLUSIONS: There has been very little research into the UV sensitivity of helminths; only 47 studies were included in this review and the majority were carried out before the standard protocol for UV disinfection experiments was published. Only 18 species were studied; however all species could be inactivated by UV light. Fluences required to achieve a 1-log inactivation ranged from 5 mJ/cm2 to over 800 mJ/cm2. Larval forms were generally more sensitive to UV light than species which remain as an egg in the environment. This review confirms that further research is required to produce detailed recommendations for household or community scale UV-C LED or solar disinfection (SODIS) of water for preventing helminthiases.

Barriers to access improved water and sanitation in poor peri-urban settlements of Abidjan, Côte d'Ivoire.

Achieving access to safe water and sanitation still pose major challenges in urban areas of sub-Saharan Africa countries, despite all the progress achieved in the last decade. This study assessed the ability of populations living in poor peri-urban settlements to access improved water and sanitation and identified factors influencing this access, in order to guide sustainable mitigating solutions to address associated health and environmental risks. We conducted a cross-sectional study in six poor peri-urban settlements of Yopougon, the largest municipality of Abidjan. A total of 556 randomly selected households were included. The factors associated with access to improved water and sanitation were identified through explanatory models using multivariate logistic regression. A proportion of 25% of all households assessed did not have access to clean water and 57% lacked improved sanitation. Socioeconomic status and settlement characteristics appear as the main indicators of poor access to reliable water and sanitation in peri-urban settlements. The presence of the household head's wife at home was associated with greater access to clean water (OR = 3.57; 95% CI: 1.74, 7.31), thus highlighting the important role of women in ensuring access to clean water in these specific environments. Household size, education and religion were not significantly associated with the two considered outcomes. Women therefore should be involved at all levels of programming in water promotion in these settlements to improve the population's well-being. While religion does not appear to play an important role in access to water and sanitation, successful interventions should involve religious communities because of their large representation.

The effectiveness of water treatment processes against schistosome cercariae: A systematic review.

BACKGROUND: Schistosomiasis is one of the most disabling neglected tropical diseases, ranking second in terms of years lived with disability. While treatment with the drug praziquantel can have immediate beneficial effects, reinfection can occur rapidly if people are in contact with cercaria-infested water. Water treatment for schistosomiasis control seeks to eliminate viable cercariae from water, thereby providing safe alternative water supplies for recreational and domestic activities including laundry and bathing. This provision may reduce contact with infested water, which is crucial for reducing reinfection following chemotherapy and cutting schistosome transmission. METHODOLOGY: A qualitative systematic review was carried out to summarize the existing knowledge on the effectiveness of water treatment in removing or inactivating human schistosome cercariae. Four online databases were searched. Studies were screened and categorized into five water treatment processes: storage, heating, chlorination, filtration, and ultraviolet (UV) disinfection. CONCLUSIONS: All five water treatment methods can remove or inactivate cercariae in water, and hence produce cercaria-free water. However, reliable design guidelines for treating water do not exist as there are insufficient data. Overall, the review found that cercariae are inactivated when storing water for 10-72 hours (depending on temperature), or with chlorination values of 3-30 mg-min/l. UV fluences between 3-60 mJ/cm2 may significantly damage or kill cercariae, and sand filters with 0.18-0.35 mm grain size have been shown to remove cercariae. This systematic review identified 67 studies about water treatment and schistosomiasis published in the past 106 years. It highlights the many factors that influence the results of water treatment experiments, which include different water quality conditions and methods for measuring key parameters. Variation in these factors limit comparability, and therefore currently available information is insufficient for providing complete water treatment design recommendations.