On-site dry sanitation facilities, although cheaper than wet sanitation systems, suffer from high malodour and insect nuisance as well as poor aesthetics. The high odour deters users from utilizing dry sanitation toilets as an improved facility leading to over 20% open defecation in Sub-Saharan Africa. To address this malodour concern, this study first assessed odour levels, using hydrogen sulphide (H2S) and ammonia (NH3) as indicators, on two dry sanitation facilities named T1 and T2. The potential of using biomass (sawdust, rice husk, moringa leaves, neem seeds), ash (coconut husk, cocoa husk) or biochar (sawdust, rice husk, bamboo) as biocovers to remove or suppress odour from fresh faecal sludge (FS) over a 12-day period was investigated. Results showed that the odour levels for H2S in both T1 (3.17 ppm) and T2 (0.22 ppm) were above the threshold limit of 0.05 ppm, for unpleasantness in humans and vice versa for NH3 odour levels (T1 = 6.88 ppm; T2 = 3.16 ppm; threshold limit = 30 ppm limit). The biomasses exhibited low pH (acidic = 5–7) whereas the biochars and ashes had higher pHs (basic = 8–13). Basic biocovers were more effective at H2S emission reduction (80.9% to 96.2%) than acidic biocovers. The effect of pH on suppression of NH3 was determined to be statistically insignificant at 95% confidence limit. In terms of H2S and NH3 removal, sawdust biochar was the most effective biocover with odour abatement values of 96.2% and 74.7%, respectively. The results suggest that biochar produced from locally available waste plant-based materials, like sawdust, can serve as a cost-effective and sustainable way to effectively combat odour-related issues associated with dry sanitation facilities to help stop open defecation.

In this study, downwind odour concentrations from a communal toilet facility were measured by trained human receptors using the plume method over a 10 day period from mid-May to mid-June 2015 over an approximate downwind area of 1000 m 2 (about 800 m long and 30 m). Source emission measurements and extensive meteorological data were collected along with the field odor concentration measurements. Modelling of the measurement events at specific receptor locations using the US EPA SCREEN3 model was compared to field odor measurements at the same locations. The study also showed how subjectivity in the use of the human nose in measuring odour strength could be reduced by selecting odour inspectors using the "Standard Procedure for Testing Individual Odour Sensitivity". Also an odour dispersion model using the US EPA SCREEN3 model was built and simulated and the output of the simulated model compared with the measured data. A paired t-test, t(5) = −1.29, p = 0.902 (p > 0.05), showed that there was no statistically significant difference between simulated model output and measured data, hence the possible of using odour dispersion models improved operation of a communal toilet in relation to odour impact.

Malodour has been identified as a barrier to utilization of sanitation facilities. It is generally recognized that for effective odour control measures to be implemented, the problem must first be quantified. With today's increasing levels of development, odour nuisance has become a major environmental issue. Citizen complaints about and reaction to odours caused by landfills (including refuse dump sites), waste water treatment plants (most of which are non-functional), public (communal) toilets, industrial processes, and other sources have made it difficult to secure sites for such facilities. Current trends show a community impact approach based on citizen involvement. This paper discusses a rapid baseline survey carried out as part of a community odour annoyance study conducted in Ayigya Zongo, an urban poor community in the Kumasi Metropolis in Ghana. The study quantified the public perception (impact) of all odours in the community through a face-to-face interview survey utilizing a structured questionnaire protocol. Responses from the survey were analysed with SPSS software program (version 20.0). Methods, results, and conclusions of the study are each discussed.

This study evaluated the health impacts of WASH interventions in 9 intervention communities against 9 control communities in disaster-prone areas in northern Ghana. We extracted community-specific data on patient-reported cases of WASH-related diseases from health facilities in the study areas. Also, we used key informant interviews and household questionnaires to seek information for validation. The impact was measured using the before-after study with concurrent control (BAC) method of Health Impact Evaluation in WASH interventions. The findings indicate a substantial increase in the number of WASH facilities across the intervention communities. However, some respondents complained of access to inadequate quantities and increase downtime of water systems when there is a breakdown. Access to improved sanitation facilities was still a challenge, although a steady increase in the number of household access to latrines was observed. We extracted about 2,315 reported cases of WASH-related diseases, comprising diarrhoea (83%), dysentery (8%), typhoid fever (7%) and intestinal worms (2%). Impacts on diarrhoea prevalence were generally lower than reported figures, and varied across the intervention communities, ranging from 0 to 7% reduction. We recommend that greater attention be given to the sustainability of the intervention to ensure service delivery, rather than as a one-time investment, to achieve more significant impacts.

On-site dry sanitation facilities, although cheaper than wet sanitation systems, suffer from high malodour and insect nuisance as well as poor aesthetics. The high odour deters users from utilizing dry sanitation toilet as an improved facility leading to over 20% open defecation in Sub-Saharan Africa. To address this malodour concern, this study first assessed odour levels, using hydrogen sulphide (H2S) and ammonia (NH3) as indicators, on two (2) dry sanitation facilities (T1 and T2). The potential of using biomass (sawdust, rice husk, moringa leaves, neem seeds), ash (coconut husk, cocoa husk) or biochar (sawdust, rice husk, bamboo) as biocovers to remove or suppress odour from fresh faecal sludge (FS) over a 12-day period was investigated. Results showed high odour levels, beyond and below the threshold limit for unpleasantness for humans on H2S (peak value: T1 = 3.17 ppm; T2 = 0.22 ppm > 0.05 ppm limit) and NH3 (peak value: T1 = 6.88 ppm; T2 = 3.16 ppm < 30 ppm limit), respectively. The biomasses exhibited low pH (acidic = 5-7) whereas the biochars and ashes had higher pHs (basic = 8-13). Acidic biocovers generally reduced NH3 emission significantly (12.5% to 64.8%) whereas basic biocovers were more effective at H2S emission reduction (80.9% to 96.2%). In terms of H2S and NH3 removal, sawdust biochar was the most effective biocover with odour abatement values of 96.2% and 74.7%, respectively. The results suggest that locally available waste plant-based materials, like sawdust, when converted to biochar can serve as a cost-effective and sustainable way to effectively combat odour-related issues associated with dry sanitation facilities to help stop open defecation.