Your search found 15 records
1 Kleinheinz, G. T.; McDermott, C. M.; Leewis, M. C.; Englebert, E. 2006. Influence of sampling depth on Escherichia coli concentrations in beach monitoring. Water Research, 40:3831-3837.
(Location: IWMI-HQ Call no: P 7660 Record No: H039406)
2 Ensink, Jeroen H. J.; Mahmood, Tariq; Dalsgaard, A. 2007. Wastewater-irrigated vegetables: Market handling versus irrigation water quality. Tropical Medicine and International Health, 12(Suppl.2):1-6.
Wastewater irrigation ; Vegetables ; Escherichia coli ; Helminths ; Health hazards ; Risks ; Urban agriculture ; Water quality ; Surveys / Pakistan / Faisalabad
(Location: IWMI HQ Call no: IWMI 631.7.5 G000 ENS Record No: H040599)
Objective and methods: Vegetables irrigated with untreated domestic wastewater were, at the time of harvest, analysed for the presence of the faecal indicator, Escherichia coli, and helminth eggs in Faisalabad, Pakistan. Vegetables from the same harvested batch were collected approximately 12 h later from the local market. Results: The survey found relatively low concentrations of E. coli (1.9 E. coli per gram), but relatively high concentrations of helminths (0.7 eggs per gram) on vegetables collected from agricultural fields. Higher concentration of both E. coli (14.3 E. coli per gram) and helminths (2.1 eggs per gram) were recovered from the vegetables collected from the market. Conclusions: The results of the survey suggest that unhygienic post harvest handling was the major source of produce contamination. Interventions at the market, such as the provision of clean water to wash produce in, are better ways to protect public health and more cost effective than wastewater treatment.
3 Machdar, E.; van der Steen, N. P.; Raschid-Sally, Liqa; Lens, P. N. L. 2013. Application of quantitative microbial risk assessment to analyze the public health risk from poor drinking water quality in a low income area in Accra, Ghana. Science of the Total Environment, 449(1):134-142. [doi: https://doi.org/10.1016/j.scitotenv.2013.01.048]
Drinking water ; Water quality ; Public health ; Biological contamination ; Risk assessment ; Water supply ; Waterborne diseases ; Households ; Income ; Cost effectiveness analysis ; Escherichia coli / Ghana / Accra
(Location: IWMI HQ Call no: e-copy only Record No: H045708)
(0.35 MB)
In Accra, Ghana, a majority of inhabitants lives in over-crowded areas with limited access to piped water supply, which is often also intermittent. This study assessed in a densely populated area the risk from microbial contamination of various sources of drinking water, by conducting a Quantitative Microbiological Risk Assessment (QMRA) to estimate the risk to human health from microorganism exposure and dose–response relationships. Furthermore the cost-effectiveness in reducing the disease burden through targeted interventions was evaluated. Five risk pathways for drinking water were identified through a survey (110 families), namely household storage, private yard taps, communal taps, communal wells and water sachets. Samples from each source were analyzed for Escherichia coli and Ascaris contamination. Published ratios between E. coli and other pathogenswere used for theQMRA and disease burden calculations. The major part of the burden of disease originated from E. coli O157:H7 (78%) and the least important contributor was Cryptosporidium (0.01%). Other pathogens contributed 16% (Campylobacter), 5% (Rotavirus) and 0.3% (Ascaris). The sum of the disease burden of these pathogens was 0.5 DALYs per person per year, which is much higher than the WHO reference level. The major contamination pathway was found to be household storage. Disinfection of water at household level was the most cost-effective intervention (b5 USD/DALY-averted) togetherwith hygiene education.Water supply network improvements were significantly less cost-effective.
4 Amoah, Philip; Nartey, E. G.; Schrecongost, A. 2016. Effect of different income housing zones on effluent quality of biofil toilet digesters in Accra, Ghana. Paper presented at the 39th WEDC International Conference: Ensuring Availability & Sustainable Management of Water and Sanitation for All, Kumasi, Ghana, 11-15 July 2016. 7p.
Household wastes ; Waste treatment ; Excreta ; Latrines ; Digesters ; Escherichia coli ; Faecal coliforms ; Helminths ; Water pollution ; Sanitation / Ghana / Accra
(Location: IWMI HQ Call no: e-copy only Record No: H047833)
http://wedc.lboro.ac.uk/resources/conference/39/Amoah-2498.pdf
https://vlibrary.iwmi.org/pdf/H047833.pdf
https://vlibrary.iwmi.org/pdf/H047833.pdf
(472 KB)
5 Amoah, Philip; Nartey, E. G.; Schrecongost, A. 2016. Performance evaluation of biofil toilet waste digester technologies in Ghana: the efficacy of effluent treatment options. Environmental Technology, 37(23):3002-3013. [doi: https://doi.org/10.1080/09593330.2016.1173116]
Performance evaluation ; Waste treatment ; Wastewater treatment ; Water table ; Water pollution ; Excreta ; Latrines ; Digesters ; Sanitation ; Escherichia coli ; Faecal coliforms ; Nutrients ; Soil sampling ; Pathogens / Ghana / Accra
(Location: IWMI HQ Call no: e-copy only Record No: H047835)
The study was carried out to assess the efficacy of a standard Biofil toilet digester with regard to its effluent quality and to evaluate the performance of new effluent polishing options being developed by BiofilCom. Infuent and effluent were collected from 18 standard Biofil digesters connected to full- flush toilets. Effluent from five pilot installations with improved effluent polishing options were also taken for analyses. Ten other Biofil installations were selected to assess the impact of digester effluent discharge on the surrounding soil. Pollutant concentrations in the Biofil effluent exceeded both Ghana EPA and WHO standards for discharge though pollutant removal efficiencies were high: 84% for biochemical oxygen demand, 86.1% for chemical oxygen demand and 82.4% for total suspended solids. Escherichia coli and total coliform levels were signi cantly reduced by 63% and 95.6%, respectively, and nutrients were the least removed from effluents. Generally, effluents from the majority of the pilot polishing options met most of the discharge standards. E. coli were present in the soil at all study sites, except one. Biofil digester effluent is discharged subsurface but comparing their effluent quality with standards for discharge into water courses is relevant especially in areas of frequent flooding and high water tables.
6 Abera, B.; Bezabih, B.; Hailu, D. 2017. Microbial quality of community drinking water supplies: a ten year (2004-2014) analyses in West Amhara, Ethiopia. Sustainability of Water Quality and Ecology, 9-10:22-26. [doi: https://doi.org/10.1016/j.swaqe.2016.06.001]
Drinking water ; Water quality ; Biological contamination ; Faecal coliforms ; Escherichia coli ; Communities ; Water supply ; Bacteriological analysis ; Chlorination / Ethiopia / West Amhara
(Location: IWMI HQ Call no: e-copy only Record No: H048430)
(0.32 MB)
Access to safe drinking water is an important public health and development issue at national, regional and local levels. Community drinking water supplies such as piped water, dug wells and springs are the predominant sources in rural villages and towns in Ethiopia. A retrospective analysis was conducted on microbial quality of community drinking water sources that had been processed from 2004–2014. Water samples were collected from 36 districts in west Amhara region. As per standard operational procedures, bacteriological analyses had been performed using multiple tube fermentation technique. A total of 1030 drinking water samples from (tap water n = 680), wells (n = 198), spring (n = 128) and reservoir (n = 24) were analyzed for microbial qualities. Overall, 29.0% (95% CI: 26.3–31.8%) and 44.7% (95% CI: 41.7–47.7%) of water samples had Escherichia coli and total coliforms (TC), respectively. Furthermore, 52.0%, 43.0%, and 20.2% of water samples from wells, spring and tap water were positive for E. coli. For faecal coliforms, 72.1% of drinking water supplies complied with World Health Organization and Ethiopian Standards. Tap water samples were 3.8 times less likely to be faecal contaminated than water samples from dug wells and spring water sources (OR = 3.8, 95% CI: 2.8–5.1, P = 0.001). This ten year trend analyses showed that microbial qualities of community drinking water supplies were not to the standards. This study reinforces the need to monitor microbial quality and chlorine treatment of community water supplies.
7 Islam, M. M. M.; Sokolova, E.; Hofstra, N. 2018. Modelling of river faecal indicator bacteria dynamics as a basis for faecal contamination reduction. Journal of Hydrology, 563:1000-1008. [doi: https://doi.org/10.1016/j.jhydrol.2018.06.077]
Water quality ; Rivers ; Biological contamination ; Faecal coliforms ; Escherichia coli ; Enterococcus ; Wastewater ; Hydrodynamics ; Models ; Performance testing ; Sensitivity analysis / Bangladesh / Betna River
(Location: IWMI HQ Call no: e-copy only Record No: H048842)
https://www.sciencedirect.com/science/article/pii/S0022169418304992/pdfft?md5=0e46b4fbb1e8dfbccf7385817bd66e44&pid=1-s2.0-S0022169418304992-main.pdf
https://vlibrary.iwmi.org/pdf/H048842.pdf
https://vlibrary.iwmi.org/pdf/H048842.pdf
(1.32 MB) (1.32 MB)
To improve microbial water quality and to prevent waterborne disease outbreaks, knowledge on the fate and transport of contaminants and on the contributions from different faecal sources to the total contamination is essential. The fate and transport of faecal indicators E. coli and enterococci within the Betna River in Bangladesh were simulated using a coupled hydrodynamic and water quality model. The hydrodynamic model for the river was set up, calibrated and validated with water level and discharge in our earlier study. In this study, the hydrodynamic model was further validated using measured water temperature and salinity and coupled with the water quality module. Bacterial load data from various faecal sources were collected and used as input in the water quality model. The model output corresponded very well with the measured E. coli and enterococci concentrations in the river; the Root Mean Square Error and the Nash-Sutcliffe efficiency for Log10-transformed concentrations were found to be 0.23 (Log10 CFU/100 ml) and 0.84 for E. coli, and 0.19 (Log10 CFU/100 ml) and 0.86 for enterococci, respectively. Then, the sensitivity of the model was tested by removing one process or forcing at a time. These simulations revealed that the microbial decay, the upstream concentrations and the discharge of untreated wastewater were the primary factors controlling the concentrations in the river, while wind and the contribution from the diffuse sources (i.e. urban and agricultural runoff) were unlikely to have a major influence. Finally, the model was applied to investigate the influence of wastewater treatment on the bacteria concentrations. This revealed that wastewater treatment would result in a considerable improvement of the microbial water quality of the Betna River. This paper demonstrates the application of a comprehensive state-of-art model in a river in a data-poor tropical area. The model can potentially be applied to other watersheds and can help in formulating solutions to improve the microbial water quality.
8 Grzybowski, M.; Lenczewski, M. E.; Oo, Y. Y. 2019. Water quality and physical hydrogeology of the Amarapura township, Mandalay, Myanmar. Hydrogeology Journal, 27(4):1497-1513. [doi: https://doi.org/10.1007/s10040-018-01922-9]
Water quality ; Hydrogeology ; Groundwater development ; Urban areas ; Groundwater table ; Aquifers ; Groundwater flow ; Drinking water ; Well construction ; Geochemistry ; Wastewater ; Escherichia coli ; Hydraulic conductivity ; Electrical conductivity ; Models / Myanmar / Mandalay / Amarapura
(Location: IWMI HQ Call no: e-copy only Record No: H049365)
https://link.springer.com/content/pdf/10.1007%2Fs10040-018-01922-9.pdf
https://vlibrary.iwmi.org/pdf/H049365.pdf
https://vlibrary.iwmi.org/pdf/H049365.pdf
(4.08 MB) (4.08 MB)
Mandalay is a major city in central Myanmar with a high urban population and which lacks a central wastewater management system, a solid waste disposal process, and access to treated drinking water. The purpose of this study is to investigate the groundwater quality of local dug wells and tube wells, determine quantitative data on characteristics of the Amarapura Aquifer, and compare seasonal variations in groundwater flow and quality. Water samples were collected during the dry and wet seasons, then analyzed for major ion chemistry using ion chromatography to identify indicators of wastewater contamination transport to the shallow aquifer and to compare seasonal variations in groundwater chemistry. An open-source analytic element model, GFLOW, was used to describe the physical hydrogeology and to determine groundwater flow characteristics in the aquifer. Hydrogeochemistry data and numerical groundwater flow models provide evidence that the Amarapura Aquifer is susceptible to contamination from anthropogenic sources. The dominant water types in most dug wells and tube wells is Na-Cl, but there is no known geologic source of NaCl near Mandalay. Many of these wells also contain water with high electrical conductivity, chloride, nitrate, ammonium, and E. coli. Physical measurements and GFLOW characterize groundwater flow directions predominantly towards the Irrawaddy River and with average linear velocities ranging from 1.76 × 10-2 m/day (2.04 × 10-7 m/s) to 9.25 m/day (1.07 × 10-4 m/s). This is the first hydrogeological characterization conducted in Myanmar.
9 Miller-Robbie, Leslie; Ramaswami, A.; Amerasinghe, Priyanie. 2017. Wastewater treatment and reuse in urban agriculture: exploring the food, energy, water, and health nexus in Hyderabad, India. Environmental Research Letters, 12(7):075005. (Focus issue: Focus on Urban Food-Energy-Water Systems: Interdisciplinary, Multi-Scalar and Cross-Sectoral Perspectives) [doi: https://doi.org/10.1088/1748-9326/aa6bfe]
Wastewater treatment plants ; Water reuse ; Urban agriculture ; Food production ; Energy consumption ; Water quality ; Health hazards ; Nexus ; Life cycle assessment ; Effluents ; Greenhouse gas emissions ; Groundwater ; Irrigation water ; Escherichia coli ; Nutrients ; Infrastructure ; Case studies ; Models / India / Hyderabad
(Location: IWMI HQ Call no: e-copy only Record No: H049799)
https://iopscience.iop.org/article/10.1088/1748-9326/aa6bfe/pdf
https://vlibrary.iwmi.org/pdf/H049799.pdf
https://vlibrary.iwmi.org/pdf/H049799.pdf
(1.16 MB) (1.16 MB)
Nutrients and water found in domestic treated wastewater are valuable and can be reutilized in urban agriculture as a potential strategy to provide communities with access to fresh produce. In this paper, this proposition is examined by conducting a field study in the rapidly developing city of Hyderabad, India. Urban agriculture trade-offs in water use, energy use and GHG emissions, nutrient uptake, and crop pathogen quality are evaluated, and irrigation waters of varying qualities (treated wastewater, versus untreated water and groundwater) are compared. The results are counter-intuitive, and illustrate potential synergies and key constraints relating to the food–energy–water–health (FEW–health) nexus in developing cities. First, when the impact of GHG emissions from untreated wastewater diluted in surface streams is compared with the life cycle assessment of wastewater treatment with reuse in agriculture, the treatment-plus-reuse case yields a 33% reduction in life cycle system-wide GHG emissions. Second, despite water cycling benefits in urban agriculture, only <1% of the nutrients are able to be captured in urban agriculture, limited by the small proportion of effluent divertible to urban agriculture due to land constraints. Thus, water treatment plus reuse in urban farms can enhance GHG mitigation and also directly save groundwater; however, very large amounts of land are needed to extract nutrients from dilute effluents. Third, although energy use for wastewater treatment results in pathogen indicator organism concentrations in irrigation water to be reduced by 99.9% (three orders of magnitude) compared to the untreated case, crop pathogen content was reduced by much less, largely due to environmental contamination and farmer behavior and harvesting practices. The study uncovers key physical, environmental, and behavioral factors that constrain benefits achievable at the FEW-health nexus in urban areas.
10 Butte, G.; Niwagaba, C.; Nordin, A. 2021. Assessing the microbial risk of faecal sludge use in Ugandan agriculture by comparing field and theoretical model output. Water Research, 197:117068. [doi: https://doi.org/10.1016/j.watres.2021.117068]
Faecal sludge ; Agriculture ; Biological contamination ; Risk assessment ; Treatment plants ; Pathogens ; Escherichia coli ; Waste management ; Risk reduction ; Vegetables ; Crops ; Fertilizers ; Farmers ; Models / Uganda / Kampala
(Location: IWMI HQ Call no: e-copy only Record No: H050481)
https://www.sciencedirect.com/science/article/pii/S0043135421002669/pdfft?md5=8d175bb8c32e02db26ee505950926fb9&pid=1-s2.0-S0043135421002669-main.pdf
https://vlibrary.iwmi.org/pdf/H050481.pdf
https://vlibrary.iwmi.org/pdf/H050481.pdf
(1.80 MB) (1.80 MB)
Reuse of faecal sludge in agriculture has many potential benefits, but also poses risks to human health. To better understand the potential risks, Quantitative Microbial Risk Assessment (QMRA) was performed for three population groups in Kampala, Uganda: wastewater and faecal sludge treatment plant workers; farmers using faecal sludge; and consumers of faecal sludge-fertilised vegetables. Two models were applied for farmers and consumers, one based on pathogen concentrations from field sampling of sludge, soils and vegetables, and one based on theoretical pathogen contribution from the last sludge application, including decay and soil to crop transfer of pathogens. The risk was evaluated for two pathogens (enterohaemorrhagic E. coli (EHEC) and Ascaris lumbricoides). The field data on sludge, soil and vegetables indicated that the last application of faecal sludge was not the sole pathogen source. Correspondingly, the model using field data resulted in higher risks for farmers and consumers than the theoretical model assuming risk from sludge only, except when negligible for both. For farmers, the yearly risk of illness, based on measured concentrations, was 26% from EHEC and 70% from Ascaris, compared with 1.2% and 1.4%, respectively, considering the theoretically assumed contribution from the sludge. For consumers, the risk of illness based on field samples was higher from consumption of leafy vegetables (100% from EHEC, 99% from Ascaris) than from consumption of cabbages (negligible for EHEC, 26% from Ascaris). With the theoretical model, the risk of illness from EHEC was negligible for both crops, whereas the risk of illness from Ascaris was 64% and 16% for leafy vegetables and cabbage, respectively. For treatment plant workers, yearly risk of illness was 100% from EHEC and 99.4% from Ascaris. Mitigation practices evaluated could reduce the relative risk by 30-70%. These results can help guide treatment and use of faecal sludge in Kampala, to protect plant workers, farmers and consumers.
11 Kelly, E.; Cronk, R.; Fisher, M.; Bartram, J. 2021. Sanitary inspection, microbial water quality analysis, and water safety in handpumps in rural Sub-Saharan Africa. npj Clean Water, 4:3. [doi: https://doi.org/10.1038/s41545-020-00093-z]
Water, sanitation and hygiene ; Water quality ; Biological contamination ; Microbiological analysis ; Risk factors ; Escherichia coli ; Drinking water ; Water supply ; Boreholes ; Manual pumps ; Rural areas ; Models / Africa South of Sahara
(Location: IWMI HQ Call no: e-copy only Record No: H050530)
(0.61 MB) (628 KB)
In sub-Saharan Africa, over half of the population is exposed to contaminated drinking water. The WHO recommends both sanitary inspection and water quality analysis to assess the risk of water source contamination, but the relationship between these tools is poorly understood. We explore the relationship between sanitary inspection and water quality analysis using data from 1028 boreholes with handpumps in 12 countries in sub-Saharan Africa. Sanitary inspection scores and E. coli occurrence were compared using the models described in published literature, and an alternative model that better reflects causal pathways of contamination. In the alternative model, sanitary risk factors were categorized as contamination sources, carriers, or barrier breakdowns, and the relationships between risk factor combinations and E. coli occurrence were assessed. We found no associations between sanitary risk score and E. coli occurrence using either the established or alternative model. These results confirm that sanitary inspections and microbial analyses convey distinct information, and perfect correlation is neither expected nor desired. The alternative model demonstrated a slightly better model fit than most established models, and the model fit further improved when the occurrence of rainfall in the past two days was added as a carrier. We recommend that: implementers train water system operators to conduct sanitary inspection; and researchers work to improve our understanding of the effect of individual sanitary risk factors, as well as incorporate contextual data into their assessments of sanitary inspection and water quality.
12 Truchado, P.; Gil, M. I.; Lopez, C.; Garre, A.; Lopez-Aragon, R. F.; Bohme, K.; Allende, A. 2021. New standards at European Union level on water reuse for agricultural irrigation: are the Spanish wastewater treatment plants ready to produce and distribute reclaimed water within the minimum quality requirements? International Journal of Food Microbiology, 365:109352. (Online first) [doi: https://doi.org/10.1016/j.ijfoodmicro.2021.109352]
Water reuse ; Irrigation water ; Wastewater treatment plants ; Water quality ; Regulations ; Irrigation systems ; Pathogenic microorganisms ; Escherichia coli ; Microbiological risk assessment ; Fruits ; Leaf vegetables ; Indicators / Spain
(Location: IWMI HQ Call no: e-copy only Record No: H050599)
(0.85 MB)
The new European regulation on minimum quality requirements (MQR) for water reuse (EU, 2020/741) was launched in May 2020 and describes the directives for the use of reclaimed water for agricultural irrigation. This Regulation will be directly applicable in all Member States from 26 June 2023. Since its publication in 2020, concerns have raised about potential non-compliance situations in water reuse systems. The present study represents a case study where three different water reuse systems have been monitored to establish their compliance with the MQR. Each water reuse system includes a wastewater treatment plant (WWTP), a distribution/storage system and an end-user point, where water is used for irrigation of leafy greens. The selected water reuse systems allowed us to compare the efficacy of water treatments implemented in two WWTPs as well as the impact of three different irrigation systems (drip, furrow and overhead irrigation). The presence and concentration of indicator microorganisms (Escherichia coli and C. perfringens spores) as well as pathogenic bacteria (Shiga toxin-producing, E. coli (STEC), E. coli O157:H7, and Salmonella spp.) were monitored in different sampling points (influent and effluent of the WWTPs, water reservoirs located at the distribution system and the end-user point at the irrigation system as well as in the leafy greens during their growing cycle. Average levels of E. coli (0.73 ± 1.20 log cfu E. coli/100 mL) obtained at the point where the WWTP operator delivers reclaimed water to the next actor in the chain, defined in the European regulation as the ‘point of compliance’, were within the established MQR (<1 log cfu/100 mL) (EU, 2020/741). On the other hand, average levels of E. coli at the end-user point (1.0 ± 1.2 log cfu/100 mL) were below the recommended threshold (2 log cfu E. coli/100 mL) for irrigation water based on the guidance document on microbiological risks in fresh fruits and vegetables at primary production (EC, 2017/C_163/01). However, several outlier points were observed among the samples taken at the irrigation point, which were linked to a specific cross-contamination event within the distribution/storage system. Regarding pathogenic bacteria, water samples from the influent of the WWTPs showed a 100% prevalence, while only 5% of the effluent samples were positive for any of the monitored pathogenic bacteria. Obtained results indicate that reclaimed water produced in the selected water reuse system is suitable to be used as irrigation water. However, efforts are necessary not only in the establishment of advance disinfection treatments but also in the maintenance of the distribution/storage systems.
13 Asirifi, I.; Kaetzl, K.; Werner, S.; Saba, C. K. S.; Abagale, F. K.; Amoah, Philip; Marschner, B. 2021. Pathogen and heavy metal contamination in urban agroecosystems of northern Ghana: influence of biochar application and wastewater irrigation. Journal of Environmental Quality, 50(5):1097-1109. [doi: https://doi.org/10.1002/jeq2.20260]
Pathogens ; Heavy metals ; Contamination ; Urban agriculture ; Agroecosystems ; Wastewater irrigation ; Helminth eggs ; Faecal coliforms ; Escherichia coli ; Vegetables ; Biochar / Ghana
(Location: IWMI HQ Call no: e-copy only Record No: H050674)
https://acsess.onlinelibrary.wiley.com/doi/epdf/10.1002/jeq2.20260
https://vlibrary.iwmi.org/pdf/H050674.pdf
https://vlibrary.iwmi.org/pdf/H050674.pdf
(0.97 MB) (993 KB)
The benefit of biochar as a soil fertility enhancer is well known and has been broadly investigated. Equally, many tropical and subtropical countries use wastewater for irrigation in urban agriculture. To assess the related health risks, we determined pathogen and heavy metal fate associated with biochar application and wastewater irrigation in the urban agriculture of northern Ghana. Rice (Oryza L.) husk biochar (20 t ha-1), N–P–K 15–15–15 fertilizer (212.5 kg ha-1), and their combinations were evaluated in a field-based experiment. Untreated wastewater and tap water served as irrigation water. Red amaranth (Amaranthus cruentus L.) was used as a test crop and was grown in wet (WS) and dry (DS) cropping seasons. Irrigation water, soil, and vegetables were analyzed for heavy metals, Escherichia coli, fecal coliform, helminth eggs, and Salmonella spp. Unlike the pathogens, analyzed heavy metals from irrigation water and soil were below the FAO/WHO permissible standard for agricultural activities. Wastewater irrigation caused E. coli concentrations ranging from 0.5 to 0.6 (WS) and from 0.7 to 0.8 (DS) log10 colony forming units per gram fresh weight (CFU gFW-1) on vegetables and from 1.7 to 2.1 (WS) and from 0.6 to 1.0 (DS) log10CFU per gram dry weight (gDW-1) in soil. Average log10CFU gFW-1 rates of 6.19 and 3.44 fecal coliform were found on vegetables, whereas in soil, 4.26 and 4.58 log10CFU gDW-1 were observed in WS and DS, respectively. Helminth egg populations were high in wastewater and were transferred to the crops and soil. Biochar did not affect bacteria contamination. Pathogen contamination on vegetables and in soil were directly linked to the irrigation water, with minimal or no difference observed from biochar application.
14 Nartey, Eric Gbenatey; Sakrabani, R.; Tyrrel, S.; Cofie, Olufunke. 2024. Storage duration and temperature affect pathogen load, heavy metals, and nutrient levels in faecal derived fertiliser. Environmental Technology, 12p. (Online first) [doi: https://doi.org/10.1080/09593330.2024.2309479]
Faecal sludge ; Fertilizers ; Storage ; Temperature ; Pathogens ; Heavy metals ; Nutrients ; Escherichia coli / Ghana
(Location: IWMI HQ Call no: e-copy only Record No: H052687)
https://www.tandfonline.com/doi/epdf/10.1080/09593330.2024.2309479?needAccess=true
https://vlibrary.iwmi.org/pdf/H052687.pdf
https://vlibrary.iwmi.org/pdf/H052687.pdf
(1.74 MB) (1.74 MB)
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.
15 Nartey, Eric Gbenatey; Sakrabani, R.; Tyrrel, S.; Cofie, Olufunke. 2023. Assessing consistency in the aerobic co-composting of faecal sludge and food waste in a municipality in Ghana. Environmental Systems Research, 12:33. [doi: https://doi.org/10.1186/s40068-023-00319-2]
Faecal sludge ; Composting ; Aerobic treatment ; Food waste ; Escherichia coli ; Traceability ; Consistency ; Feedstocks / Ghana
(Location: IWMI HQ Call no: e-copy only Record No: H052688)
https://environmentalsystemsresearch.springeropen.com/counter/pdf/10.1186/s40068-023-00319-2.pdf
https://vlibrary.iwmi.org/pdf/H052688.pdf
https://vlibrary.iwmi.org/pdf/H052688.pdf
(1.84 MB) (1.84 MB)
Background: A faecal sludge (FS) co-composting study assessed the extent of consistency in compost characteristics between and within batches. The study focused on the consistency of the co-composting process by measuring the variability of key parameters.
Method: The set up consisted of 12 FS and food waste (FW) co-composting piles in three successive batches (1, 2 and 3). Consistency was assessed in the three successive batches of co-composted FS and food waste (FW). Within batches, consistency was assessed in each of them by dividing it into four separate replicate piles. Characteristics of interest were E. coli, as well as selected physico-chemical parameters (pH, EC, Mg, Ca, N, NH4-N, NO3-N, P, avail. P, and K) and heavy metals (Se, Fe, Cd, Cu, Hg, Ni, Pb and Cr). Data were subjected to analysis of variance (ANOVA) using SPSS.
Result: Results show that, E. coli levels were not consistent between the successive batches during the entire co-composting process. While variations between batches were only observed for EC and nutrient parameters, variations were evident for several measured characteristics within batches. The measured coefficient of variations (CVs) within batches ranged between 0–125% and 3–111% for heavy metals and nutrients, respectively.
Conclusion: In conclusion, there was less consistency in nutrients between successive batches and CV within batches was wide. Consistency levels for E. coli may not be an issue if pathogen inactivation is complete.
Recommendation: It is recommended that a threshold value be created for determining what is an acceptable level of variation in FS co-composting.
Method: The set up consisted of 12 FS and food waste (FW) co-composting piles in three successive batches (1, 2 and 3). Consistency was assessed in the three successive batches of co-composted FS and food waste (FW). Within batches, consistency was assessed in each of them by dividing it into four separate replicate piles. Characteristics of interest were E. coli, as well as selected physico-chemical parameters (pH, EC, Mg, Ca, N, NH4-N, NO3-N, P, avail. P, and K) and heavy metals (Se, Fe, Cd, Cu, Hg, Ni, Pb and Cr). Data were subjected to analysis of variance (ANOVA) using SPSS.
Result: Results show that, E. coli levels were not consistent between the successive batches during the entire co-composting process. While variations between batches were only observed for EC and nutrient parameters, variations were evident for several measured characteristics within batches. The measured coefficient of variations (CVs) within batches ranged between 0–125% and 3–111% for heavy metals and nutrients, respectively.
Conclusion: In conclusion, there was less consistency in nutrients between successive batches and CV within batches was wide. Consistency levels for E. coli may not be an issue if pathogen inactivation is complete.
Recommendation: It is recommended that a threshold value be created for determining what is an acceptable level of variation in FS co-composting.
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