Safe resource recovery from faecal sludge: evidence from an innovative treatment system in rural Tanzania

2020 ◽  
Vol 6 (6) ◽  
pp. 1737-1748
Author(s):  
Emmanuel C. Mrimi ◽  
Fatuma J. Matwewe ◽  
Christopher C. Kellner ◽  
Jacqueline M. Thomas

A novel treatment system for pit latrine faecal sludge; solar-dried sludge with captured leachate heat-treated in agriculture using waste-fired rocket stove.

2021 ◽  
Vol 13 (9) ◽  
pp. 4702
Author(s):  
Khumbo Kalulu ◽  
Bernard Thole ◽  
Theresa Mkandawire ◽  
Grant Kululanga

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.


2019 ◽  
Vol 13 (7) ◽  
pp. 260-272 ◽  
Author(s):  
Madalitso Tembo James ◽  
Matanda Richard ◽  
Nzali Banda Ian ◽  
Mwanaumo Erastus ◽  
Nyirenda Edwin ◽  
...  

2006 ◽  
Vol 28 (3) ◽  
pp. 295-298 ◽  
Author(s):  
Fumihisa Kobayashi ◽  
Rumiko Kofuji ◽  
Yuya Yamashita ◽  
Yoshitoshi Nakamura

2010 ◽  
Vol 62 (7) ◽  
pp. 1580-1586 ◽  
Author(s):  
S. Fach ◽  
S. Fuchs

Modern wastewater treatment plants are often inappropriate for communities in developing countries. Such communities lack the funding, resources and skilled labour required to implement, operate, and maintain these plants. This research was conducted to investigate and establish an appropriate wastewater treatment system for the district of Gunung Kidul, Indonesia. Due to its lack of water during the dry season, this district is considered one of the poorest areas in the nation. First, wastewater was stored in septic tank units for a retention time of 26 days. Anaerobic conditions occurred, resulting in an 80% reduction of initial COD. The retained sludge was well stabilized with great potential, if dewatered, for reuse as fertilizer. Consequently, supernatant was separated for experiments consisting of lab scale aerobic sand filtering unit. Through filtration, further removals of COD (about 30%) and pathogens were achieved. Rich in nitrogen, the resulting effluent could be used for irrigation and soil conditioning. With faecal sludge and also a mixture of septic sludge and food waste, the hydrolysis stage of anaerobic digestion was examined. This paper discusses the laboratory findings in Karlsruhe and the design and implementation of a treatment system in Glompong, Indonesia.


2015 ◽  
Vol 5 (3) ◽  
pp. 373-380 ◽  
Author(s):  
El hadji Mamadou Sonko ◽  
Cheikh Diop ◽  
Mbaye Mbéguéré ◽  
Alsane Seck ◽  
Amadou Guèye ◽  
...  

To optimize faecal sludge (FS) treatment plants in operation in Dakar (Senegal), this study was conducted to test the effectiveness of the solid/liquid separation on unplanted drying beds under different loading rates and two operation strategies (one or two feedings per campaign). Clogging, purification performances, dryness and hygienic quality were monitored. Results have shown that the load fractionation has reduced the clogging. Only removals of total solids (TS) and slightly those of total Kjeldahl nitrogen and chemical oxygen demand are influenced by the loading rate and the feeding mode. The reduction of faecal coliforms (FC) and helminth eggs (HE) in leachates is, respectively, 1 log unit and 100%. Two to nine days were sufficient to obtain a dryness higher than 80% TS with nominal loads of 13.7–122 kg/m2*year. Concentrations of the dried sludge in FC and HE were, respectively, about 7.104 FCU/100 g and 46 eggs/g with a reduction of 3 log unit after 15 days of drying and 32% in the sludge stored during 30 days. Unplanted beds are not effective for the treatment of low concentrated FS. The use of other technologies such as planted drying beds could be advisable in these types of sludge.


2021 ◽  
Vol 11 (24) ◽  
pp. 11772
Author(s):  
Matthew Mamera ◽  
Johan J. van Tol ◽  
Makhosazana P. Aghoghovwia ◽  
Alfredo B. J. C. Nhantumbo ◽  
Lydia M. Chabala ◽  
...  

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.


2019 ◽  
Vol 38 (1) ◽  
pp. 97-115
Author(s):  
Isabela T. Mkude ◽  
Tolly Mbwette ◽  
Richard J. Kimwaga ◽  
Sara Gabrielsson

In this work, a conceptual framework for faecal sludge (FS) management and resource recovery in Dar es Salaam city was developed. Material Flow Analysis (MFA) approach was used to assess and quantify the current materials and nutrients to support on decisions for nutrient recovery and minimize environmental pollution in three unplanned settlements of Manzese, Keko and Kipawa in Dar es Salaam city. Nitrogen and Phosphorus were chosen as indicators for the evaluation of the process. The results showed that about 75% of the Dar es Salaam city population relies on pit latrines and 15% connected to septic tanks, translating to a large amount of faecal sludge being contained onsite. The situational analysis study on faecal sludge management (FSM) showed that the collection, treatment and proper disposal of FS are the major challenges that pose risks to public health. Currently, 57% of faecal sludge generated in Dar es Salaam is disposed to the environment inappropriately. Onsite Sanitation Systems in all study areas are the main polluters, discharging large quantity of nutrients to the environment. About 37.7% of faecal sludge is with large amount of nutrients emptied from onsite sanitation systems discharged to the environment and through seepage to the groundwater.


Water SA ◽  
2020 ◽  
Vol 46 (4 October) ◽  
Author(s):  
Yasmine Shafiq ◽  
Stuart Haigh ◽  
Rochelle Holm ◽  
Alison Parker

In 2017, 55% of the global population were without safely managed sanitation services. On-site sanitation solutions, such as pit latrines, provide the majority of sanitation coverage across developing countries. Appropriate technologies are required in order to safely empty these latrines without damage to people or the environment. The design of appropriate emptying technologies can be hampered by a lack of knowledge of the mechanical properties of the waste, such as its strength. This paper will develop a calibration for a dynamic cone penetrometer to give accurate measurements of faecal sludge strength against a standard scale, rendering existing data comparable. It will be shown that the maximum shear strengths of faecal sludge found in practice are substantially greater than those previously reported; some pit latrines contain faecal sludge with strength values of 5–20 kPa at the surface, and exceeding 80 kPa at depth.


2019 ◽  
Vol 45 (4) ◽  
pp. 395-402
Author(s):  
Dylan Collings ◽  
Roman Tandlich ◽  
Cyril S. Dube ◽  
Phindile Madikizela ◽  
Nosiphiwe P. Ngqwala ◽  
...  

This study describes the results of a series of laboratory experiments on aimed at developing of a protocol for the use of fly ash as a pit additive in the ventilated improved pit latrines (VIPs) in South Africa. Model VIP vaults were prepared in the laboratory and filled with synthetic faecal sludge; and dosed with fly ash in amounts ranging from 5 to 20 % (w/w). The maximum leachable chemical oxygen demand (COD) accounted for 3.2 % of the total organic matter, while the maximum leachable ammonium accounted for 1.4 % of the leachable ammonium present in the synthetic faecal sludge. All phosphate in the synthetic faecal material was leachable. Mixing of the 20 % dose of fly ash into the synthetic faecal sludge resulted a minimum 98.9 % reduction (or about two log units) in the faecal coliform concentration after 28 days of incubation. As a result, addition of fly ash can decrease microbial threats to public and environmental health threats from the VIP faecal wastes, but can cause environmental contamination with phosphate. The fly ash dose and the duration of the faecal sludge treatment require further optimisation. Relationship between the chemical composition of the fly ash used as an additive to stabilise the VIP faecal sludge and the leaching of phosphorus from the sludge will also have to be investigated further.


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