Storage duration and temperature affect pathogen load, heavy metals, and nutrient levels in faecal derived fertiliser.

There are debates regarding the safety of faecal derived fertiliser (FDF) due to notions that harmful substances may persist at undetectable levels. A major concern is the recolonisation of indigenous pathogens and nutrient changes while undergoing storage. Abiotic factors such as duration and temperature on indigenous pathogen re-growth and nutrient during FDF storage have received little research attention. In this study, we assess the effect of varying storage temperature conditions and duration on indigenous E. coli re-growth and NPK changes of different FDF (enriched co-compost, NECo and co-compost, Co) during storage. A 2 × 3 × 6 factorial design was used with factors: fertiliser, temperature, and duration. The factorial had 36 experimental conditions in a completely randomised design with three replications. FDF samples were collected monthly for 6 months and analysed for pH, EC, organic carbon, N, NH4-N, NO3-N, P, K, E. coli, and total coliform. Findings show storage temperature and duration did not affect indigenous E. coli re-growth and total N in stored NECo and Co. However, NH4-N concentrations of NECo decreased between 27% and 55% with increasing duration of storage at lower temperatures (5°C and 25°C). The significance of this study for the FDF industry is that it is safe after storage and longer storage do not necessarily influence nutrient losses in stored FDF. Future studies are recommended to investigate the effect of moisture on stored FDF.

Integrating GIS and remote sensing for land use/land cover mapping and groundwater potential assessment for climate-smart cocoa irrigation in Ghana.

Although Ghana is a leading global cocoa producer, its production and yield have experienced declines in recent years due to various factors, including long-term climate change such as increasing temperatures and changing rainfall patterns, as well as drought events. With the increasing exposure of cocoa-producing regions to extreme weather events, the vulnerability of cocoa production is also expected to rise. Supplemental irrigation for cocoa farmers has emerged as a viable adaptation strategy to ensure a consistent water supply and enhance yield. However, understanding the potential for surface and groundwater irrigation in the cocoa-growing belt remains limited. Consequently, this study aims to provide decision-support maps for surface and groundwater irrigation potential to aid planning and investment in climate-smart cocoa irrigation. Utilizing state-of-the-art geospatial and remote sensing tools, data, and methods, alongside in-situ groundwater data, we assess the irrigation potential within Ghana's cocoa-growing areas. Our analysis identified a total area of 22,126 km2 for cocoa plantations and 125.2 km2 for surface water bodies within the cocoa-growing regions. The multi-criteria analysis (MCA) revealed that approximately 80% of the study area exhibits moderate to very high groundwater availability potential. Comparing the MCA output with existing borehole locations demonstrated a reasonable correlation, with about 80% of existing boreholes located in areas with moderate to very high potential. Boreholes in very high potential areas had the highest mean yield of 90.7 l/min, while those in low groundwater availability potential areas registered the lowest mean yield of 58.2 l/min. Our study offers a comprehensive evaluation of water storage components and their implications for cocoa irrigation in Ghana. While groundwater availability shows a generally positive trend, soil moisture and surface water have been declining, particularly in the last decade. These findings underline the need for climate-smart cocoa irrigation strategies that make use of abundant groundwater resources during deficit periods. A balanced conjunctive use of surface and groundwater resources could thus serve as a sustainable solution for maintaining cocoa production in the face of climate change.

The contribution of tipping fees to the operation, maintenance, and management of fecal sludge treatment plants: The case of Ghana.

Globally, collection of tipping fees is being promoted as a solution to sustain the operation of fecal sludge treatment plants (FSTPs). Currently, there are six large-scale FSTPs in Ghana, of which five were in operation in June 2017. In Kumasi, Sekondi-Takoradi and Tamale, fecal sludge (FS) is co-treated with landfill leachate using waste stabilization ponds (WSPs). In Tema and Accra, FS is treated using WSPs and a mechanical dewatering system coupled with an upflow anaerobic sludge blanket (UASB). The focus of this study is FSTPs and to assess how, and if, the tipping fees set by the municipalities could enable cost recovery to sustain their long-term operation. Using a questionnaire survey to interview plant managers from the public and private sectors, and directors of waste management departments, we found that the overall average operation, maintenance and management (OM&M) costs per 1000 m3 of treated waste (FS or FS + leachate) in 2017 were USD89 in Kumasi, USD150 in Tamale, USD179 in Tema, USD244 in Sekondi-Takoradi and USD1,743 in Accra. There were important disparities between FSTPs due to their scale, age, and level of treatment and monitoring. Currently, most FSTPs charge tipping fees that range between USD310 and USD530/1000 m3 of FS, averaging USD421 ± 98/1000 m3 of FS discharged at FSTPs. Our study also showed that the OM&M costs of large-scale intensive FSTPs cannot be sustained by relying solely on tipping fees. However, there could be potential to cover the routine expenditures associated with operating smaller FSTPs that relying on WSP technologies.

Crops and farmers' response to application of fecal sludge derived - Fortifer™ in different agro-ecological zones in Ghana.

Fecal sludge (FS)-derived fertilizer material, Fortifer™ was used in farmers' field to cultivate different crops under varying soil and agro-climatic conditions in Ghana. The aim was to (1) create awareness among smallholder farmers for widespread use of Fortifer™ (2) observe the response of crops to Fortifer™ application by farmers in different agro-ecological zones (3) obtain farmers feedback on the FS-derived product to enhance further dissemination across the country. In total 95 farmers in six locations participated in the farmer-led pilots. Fortifer™ containing up to 3.0% nitrogen, 3.6% phosphorus, 1.3% potassium and 44.3% organic matter was applied to tomato, rice, maize and pepper in comparison to inorganic fertilizers at recommended rates. Subsequently, farmers' perception of, and willingness to use the product were studied. Crop yield was significantly higher (p ≤ 0.05) in the Fortifer™ plots compared to the inorganic fertilizer plots for all the selected crops. Yield was 12% higher for tomato, 27% for rice and maize and 30% for pepper under the Fortifer™ plots. Farmers indicated that, nutrient content was the most important factor they consider when making fertilizer purchasing decision.

Co-composting of faecal sludge and organic solid waste for agriculture: process dynamics.

This paper presents the potentials and performance of combined treatment of faecal sludge (FS) and municipal solid waste (SW) through co-composting. The objectives were to investigate the appropriate SW type, SW/FS mixing ratio and the effect of turning frequency on compost maturity and quality. Solid waste (SW, as market waste, MW, or household waste, HW) was combined with dewatered FS in mixing ratios of 2:1 and 3:1 by volume and aerobically composted for 90 days. Four composting cycles were monitored and characterised to establish appropriate SW type and mixing ratio. Another set of five composting cycles were monitored to test two different turning frequencies: (i) once in 3-4 days during the thermophilic phase and 10 days during maturation phase and (ii) once in every 10 days throughout the composting period. Samples were taken at every turning and analysed for total solids (TS), total volatile solids (TVS), total organic carbon (TOC), electrical conductivity (EC), pH, ammonium and nitrate nitrogen (NH(4)-N and NO(3)-N) and total Kjeldahl nitrogen (TKN). Temperature, C/N ratio, NO(3)-N/NH(4)-N ratio and cress planting trials were chosen as maturity indicators. Result showed a preference of MW over HW and mixing ratio of 2:1 over 3:1. There was no significant effect of different turning frequencies on the temperature changes and the quality of mature compost. The final product contained C/N ratio of 13 and NO(3)/NH(4)-ratio of about 7.8, while TVS was about 21% TS and the NH(4)-N content was reduced to 0.01%. A co-composting duration of 12 weeks was indicated by the cress test to achieve a mature and stable product. The turning frequency of 10 days is recommended as it saves labour and still reaches safe compost with fairly high nutrient content.

Production and storage of N-enriched co-compost.

Recovery of the organic fraction of municipal waste for peri-urban agriculture could contribute to the improvement of environmental sanitation and increase agricultural productivity in Sub-Saharan Africa. However, municipal waste co-compost (Co) has low nitrogen (N) content. Therefore, this study investigated the type and form of inorganic N fertiliser that is capable of improving the nitrogen content of Co and monitored the changes in the properties of this N-enriched product under storage. To attain 30,000 mg kg(-1) (3%) N content, different amounts of urea or ammonium sulphate were applied in various forms (dry, paste and liquid) to enrich Co. The product termed comlizer was stored and its moisture, pH, total nitrogen, NH(4)(+)-N, NO(3)(-)-N, and C/N ratio were monitored under ambient conditions for two years. In the first four months of storage, total N content of 50 kg Co+3.26 kg urea (CoUD) increased from 31,333 to 54,000 mg kg(-1), and 50 kg Co+7.14 kg (NH(4))(2)SO(4) (CoASD) from 35,333 to 52,000 mg kg(-1). At the end of two years of storage, the initial N content of CoUD and CoASD decreased by 47% and 24%, respectively. Based on these results, it is recommended that dry (NH(4))(2)SO(4) should be used in N enrichment of Co, and that the comlizer should be stored in sealed bags but not more than four months.

Helminth eggs inactivation efficiency by faecal sludge dewatering and co-composting in tropical climates.

This study investigates helminth eggs removal and inactivation efficiency in a treatment process combining faecal sludge (FS) dewatering and subsequent co-composting with organic solid waste as a function of windrow turning frequency. Fresh public toilet sludge and septage mixed at a 1:2 ratio were dewatered on a drying bed. Biosolids with initial loads of 25-83 helminth eggs/g total solids (TS) were mixed with solid waste as bulking material for co-composting at a 1:2 volume ratio. Two replicate sets of compost heaps were mounted in parallel and turned at different frequencies during the active composting period: (i) once every 3 days and (ii) once every 10 days. Turning frequency had no effect on helminth eggs removal efficiency. In both setups, helminth eggs were reduced to <1 viable egg/g TS, thereby complying with the WHO guidelines 2006 for the safe reuse of FS.