Potential Use of Biochar in Pit Latrines as a Faecal Sludge Management Strategy to Reduce Water Resource Contaminations: A Review

Faecal sludge management (FSM) in most developing countries is still insufficient. Sanitation challenges within the sub-Saharan region have led to recurring epidemics of water- and sanitation-related diseases. The use of pit latrines has been recognised as an option for on-site sanitation purposes. However, there is also concern that pit latrine leachates may cause harm to human and ecological health. Integrated approaches for improved access to water and sanitation through proper faecal sludge management are needed to address these issues. Biochar a carbon-rich adsorbent produced from any organic biomass when integrated with soil can potentially reduce contamination. The incorporation of biochar in FSM studies has numerous benefits in the control of prospective contaminants (i.e., heavy metals and inorganic and organic pollutants). This review paper evaluated the potential use of biochar in FSM. It was shown from the reviewed articles that biochar is a viable option for faecal sludge management because of its ability to bind contaminants. Challenges and possible sustainable ways to incorporate biochar in pit latrine sludge management were also illustrated. Biochar use as a low-cost adsorbent in wastewater contaminant mitigation can improve the quality of water resources. Biochar-amended sludge can also be repurposed as a useful economical by-product.

Analysis of Factors Affecting the Contamination of Entamoeba sp. cyst and Soil-Transmitted Helminths egg on Dug Well Water

Dug well water is often polluted by fecal waste containment such as septic tank and pit latrine system due to its distance. The common pathogenic parasites found in fecal waste containment are E. histolytica and Soil-Transmitted Helminths (STH). The port de entry of both parasites is ingestion of contaminated food or water by fecal materials. This study was aimed to analyze factors affecting the existence of Entamoeba sp. cyst and STH egg on dug well water in Bungatan Village, Situbondo. This observational analytic study used cross-sectional approach, carried out 30 respondents in Bungatan Village, Situbondo. Entamoeba sp. cyst and STH egg were examined using sedimentation method, the distance of fecal waste containment to dug well measured by measuring tape. The characteristic of fecal waste containment and dug well was observed using questionnaires. The results showed 100% fecal containment used pit latrine system, 100% had an incomplete well standard, 66,7% had unstandardized distance with fecal waste containment. Entamoeba sp. cyst and STH egg were not found on all water samples. The soil condition near the dug well (acidity, temperature, moisture, and sunlight intensity) and physical condition (temperature) of dug well water were inappropriate to the development of Entamoeba sp. cyst and STH egg. The dug well's component and its distance to fecal containment did not affect Entamoeba sp. cyst and STH egg existence in all dug well water. The physical soil condition near the dug well and the temperature of dug well water were inappropriate to the development of both parasites. Keywords: Entamoeba sp., Soil Transmitted Helminths, Dug Well, Fecal Waste Containment

Latrine characteristics and maintenance practices associated with pit latrine lifetime in an informal settlement in Kampala, Uganda

This study assessed latrine characteristics and maintenance practices associated with an extended pit latrine lifetime in an informal settlement in Kampala, Uganda. Data were obtained from 306 respondents on sociodemographic characteristics, their private pit latrine characteristics and latrine lifetime. A modified Poisson regression was used to model the latrine characteristics and maintenance practices associated with the pit latrine lifetime. All analyses were performed using Stata 14 software. Approximately 23.5% of the pit latrines had a lifetime of less than 2 years, and most latrines were reportedly desludged (64.7%) or regularly cleaned for maintenance (27.1%) as a way of extending lifetime. Pit latrine lifetime extension was higher in male-headed households (prevalence ratio (PR) 1.12, 95% confidence interval (CI) 1.00–1.25), households with a smaller number of users (unshared vs shared latrines) (PR 1.15, 95% CI 1.02–1.29) and where desludging of pits was regularly done (PR 1.53, 95% CI 1.17–1.99), while post-primary education level was negatively associated with extended latrine lifetime (PR 0.88, 95% CI 0.77–0.99). Deliberate efforts, including sensitizing communities on desludging and provision of non-shared household sanitary facilities, are needed to improve latrine maintenance and consequently extend latrine lifetime.

Development of Models for the Rational Design of Different Shapes of Pit Latrine

Specific models for the rational design of pit latrines of different shapes and sizes are presently non-existent. What exist are general design models irrespective of the shape and size of latrine which may not give the actual design parameters needed. This research was limited to the derivation of models that will aid the design of the capacity of pit latrines of different shapes and dimensions for different population of users and under different soil formations and ground conditions. The objective of this research was to derive models for the rational design of pit latrines of different shapes using data collected from 500 different household pit latrines already filled up. Thus, models were derived for different latrine pit shapes and sizes using data collected through the administration of designed questionnaire on 500 households having pit latrines already filled up. Models were developed specifically for different latrine shapes whereas those of other researchers were generalized. These models were calibrated and verified for the rational design of pit latrines of different shapes and sizes. The regression coefficients for calibration were 0.75, 0.65, and 0.50 and for verification are 0.97, 0.98 and 0.99 for square, circular and rectangular pits respectively. The implication of this research is availability of design models for the construction of different pit latrine shapes.

Development of Models for the Rational Design of Different Shapes of Pit Latrine

Specific models for the rational design of pit latrines of different shapes and sizes are presently non-existent. What exist are general design models irrespective of the shape and size of latrine which may not give the actual design parameters needed. This research was limited to the derivation of models that will aid the design of the capacity of pit latrines of different shapes and dimensions for different population of users and under different soil formations and ground conditions. The objective of this research was to derive models for the rational design of pit latrines of different shapes using data collected from 500 different household pit latrines already filled up. Thus, models were derived for different latrine pit shapes and sizes using data collected through the administration of designed questionnaire on 500 households having pit latrines already filled up. Models were developed specifically for different latrine shapes whereas those of other researchers were generalized. These models were calibrated and verified for the rational design of pit latrines of different shapes and sizes. The regression coefficients for calibration were 0.75, 0.65, and 0.50 and for verification are 0.97, 0.98 and 0.99 for square, circular and rectangular pits respectively. The implication of this research is availability of design models for the construction of different pit latrine shapes.

Modeling the Filling Rate of Faeces in Ordinary Pit Latrines

Faecal sludge deposited into the pit latrine is subject to biodegradation. The aim of this research was to develop model for the filling rate of faeces in ordinary pit latrine together with the effect of shape factor on such fillings to prepare the minds of users on the filling characteristics of the pit based on contents, usage and environmental factors. Consequently, faecal sludges sampled from 100 pits already filled were subjected to laboratory analyses for their physico-chemical and biological characteristics. Models for the actual filling rate of faeces in ordinary pit latrines were derived using BOD, COD, VS, and TS data, calibrated and verified. For a more critical situation, models were also derived for the filling rates considering pit shapes that gave the actual pit filling in comparison with the general condition. From the results, the actual filling rate was lower than those obtained using BOD, VS and TS. However, the COD gave filling rate closer to the actual filling rate than other parameters since TS could not be used to assess the filling rate of faeces in pit latrines. The pits exhibited low filling rate in terms of BOD in 2 pits. In terms of COD, the filling rate was higher compared with that of BOD. Low filling rate was observed with volatile solids and only 3 pits exhibited moderately high filling rates whereas total solids had the highest number of pits with high filling rates. The filling rates for both the square and rectangular pits increased by 26.5% from 40 – 90 ℓ/capita/year to 50 – 112 ℓ/capita/year due to the shape factor and this was above the values obtained in existing models while that of the circular pit remained the same. Reduction in pit volume and increase in filling rate by faeces was due to dead corners as a result of clogging, thereby reducing the area available for faecal infiltration into the surrounding soil. Circular pits are more stable because of the natural arching effect of the ground around the hole and there are no corners to concentrate the stresses. Pits with flat sides are much more likely to develop clogging resulting to dead corners than the circular pit. From this study, it is therefore evident that the shape of pit latrine determines the actual volume and the filling rate of faeces in pit latrine taking into consideration geological and environmental factors. Thus for optimal design, our engineers should take note of the pit shape factor. Thus, the model can be used to determine the filling rate of ordinary pit latrines considering soil characteristics, ground conditions and other favourable conditions.

Modeling the Filling Rate of Faeces in Ordinary Pit Latrines

Faecal sludge deposited into the pit latrine is subject to biodegradation. The aim of this research was to develop model for the filling rate of faeces in ordinary pit latrine together with the effect of shape factor on such fillings to prepare the minds of users on the filling characteristics of the pit based on contents, usage and environmental factors. Consequently, faecal sludges sampled from 100 pits already filled were subjected to laboratory analyses for their physico-chemical and biological characteristics. Models for the actual filling rate of faeces in ordinary pit latrines were derived using BOD, COD, VS, and TS data, calibrated and verified. For a more critical situation, models were also derived for the filling rates considering pit shapes that gave the actual pit filling in comparison with the general condition. From the results, the actual filling rate was lower than those obtained using BOD, VS and TS. However, the COD gave filling rate closer to the actual filling rate than other parameters since TS could not be used to assess the filling rate of faeces in pit latrines. The pits exhibited low filling rate in terms of BOD in 2 pits. In terms of COD, the filling rate was higher compared with that of BOD. Low filling rate was observed with volatile solids and only 3 pits exhibited moderately high filling rates whereas total solids had the highest number of pits with high filling rates. The filling rates for both the square and rectangular pits increased by 26.5% from 40 – 90 ℓ/capita/year to 50 – 112 ℓ/capita/year due to the shape factor and this was above the values obtained in existing models while that of the circular pit remained the same. Reduction in pit volume and increase in filling rate by faeces was due to dead corners as a result of clogging, thereby reducing the area available for faecal infiltration into the surrounding soil. Circular pits are more stable because of the natural arching effect of the ground around the hole and there are no corners to concentrate the stresses. Pits with flat sides are much more likely to develop clogging resulting to dead corners than the circular pit. From this study, it is therefore evident that the shape of pit latrine determines the actual volume and the filling rate of faeces in pit latrine taking into consideration geological and environmental factors. Thus for optimal design, our engineers should take note of the pit shape factor. Thus, the model can be used to determine the filling rate of ordinary pit latrines considering soil characteristics, ground conditions and other favourable conditions.

Resource-Efficient Characterisation of Pit Latrine Sludge for Use in Agriculture

Resource recovery through reuse of by-products of the sanitation chain presents a great potential towards ensuring universal access to safely managed sanitation. Many developing countries are faced with uncertainty over public and environmental health concerns associated with use of faecal sludge in agriculture. Due to resource constraints, limited data exists on the characteristics of faecal sludge to inform proper and safe use in agriculture. Despite predictive characterisation being demonstrated to be a resource-efficient approach to generate data in other fields, its application in agricultural resource recovery from faecal sludge is lacking in the literature. This paper explored predictive modelling as a less resource-intensive approach for characterisation of nutrients and pathogens in faecal sludge. Specifically, it investigated the extent to which gravimetric parameters could predict nutrients and pathogens in pit latrine sludge from informal settlements in the cities of Malawi. The study explored predictive models to estimate total ammoniacal nitrogen (TAN), total phosphorus (TP), E.coli and helminth eggs from gravimetric parameters (total solids [TS] and total volatile solids [TVS]) in pit latrine sludge. The models developed in the study allow substantially reliable estimation of TAN (R2pred = 75.4%) and TP (R2pred = 78.2%); they also provide moderately reliable predictions for E.coli (R2pred = 69.1%) and helminth eggs (R2pred = 74.3%) from total solids. Since total solids are easy and inexpensive to measure, the models present an option that can reduce resource requirement for characterisation of pit latrine sludge for informed decision-making when using pit latrine sludge in agriculture. In the absence of data on faecal sludge characteristics at the national level, the models provide a starting point for estimation of pathogens and nutrients in sludge for agricultural use. However, stepwise refinement of the models needs to be done through their validation for different types of sludge and inclusion of spatially available demographic, technical and environmental (SPA-DET) data.

Sanitation Practices and Microbial Quality of Drinking Water in Open Defaecation Free and Open Defaecation Communities in the Savelugu Municipality

Open defaecation leads to faecal matter contamination of drinking water which can cause water borne diseases. The study assessed the linkage between sanitation practices and microbial quality of drinking water of open defaecation free and open defaecation communities in the Savelugu Municipality. A cross-sectional survey of 170 households was conducted in five open defaecation free and five open defaecation communities in the Savelugu Municipality. A total of 78 samples were collected from water sources and households and analysed for Escherichia coli, Salmonella spp and Shigella spp. Sanitation facilities used by the residents included pit latrine (88.24%), no latrine (11.17%), and flush (0.59%). The study observed improper disposal of children faeces in the communities. E. coli count ranged from 0 to 15 CFU/100 ml in open defaecation free communities and 0 to 32 CFU/100 ml in open defaecation communities. The microbial load in the drinking water from open defaecation communities was higher than open defaecation free communities. Open defaecation practice leads to contamination of household water probably due to unsanitary. Community Led Total Sanitation (CLTS) should be encouraged in open defaecation communities.