scholarly journals Onsite sanitation and quantification of faecal sludge in the city of Yaoundé in Cameroon

2021 ◽  
Vol Unlabeled volume ◽  
Author(s):  
Marie Mbang ◽  
Emmanuel Ngnikam ◽  
Boniface Efon ◽  
Pierre Meukam ◽  
Stéphane Fokou
Keyword(s):  
Accumulation Rate ◽  
Domestic Wastewater ◽  
Production Method ◽  
Annual Growth Rate ◽  
Septic Tanks ◽  
Stratified Sample ◽  
Sanitation Systems ◽  
Sample Method ◽  
The City ◽  
Faecal Sludge

This study aims to describe the onsite sanitation and the quantification of faecal sludge in the city of Yaoundé. The city of Yaoundé, The population of Yaoundé City is about 3.1 million inhabitants in 2018 , will reach 4.7 million in 2030 with an average annual growth rate of 3.5%. The city of Yaoundé is dominated by an autonomous sanitation system which is used by 99% of households. Domestic wastewater of the city is mainly dealt through on-site sanitation systems represented by septic tanks, traditional pit latrines, ventilated improved pit latrines, etc A survey was carried out among 1100 households in the city of Yaoundé. The choice of household to be surveyed was made according to the stratified sample method. It is reviewed, the methods of quantification of existing used sludge, in order to choose a method adapted to the context of the city of Yaoundé. Several criteria are analyzed to access to the sludge produced by households: the existence or not of roads, their state of deterioration, the types of sanitation structure, the position of the structure in relation to the waterways, etc. Among the methods for quantifying the sludge explored, we found that "the specific production method" is more adapted in the context. But this method has been revised in order to integrate the analyzing elements on the accessibility of the facilities. The application of the method used has been done on 120 pit emptying during two months (june and july 2018). The choice of these pits as been done hazardly on the potential of 600 pit emptying in the city of Yaoundé during this period. The accumulation rate of faecal sludge in the city of Yaoundé is of 0.356 l/hab/jour for septic tanks and of 0.21 l/hab/jour for pit latrines. It equally varies according to the luxury of the habitat. At the scale of the city, in 2018, 41% of single pits and 84% of septic tanks can be drained by trucks. The interval between two emptying is of 7 years for septic tanks and 10 years for pit latrines. Finally, the city of Yaoundé produces 2018, 283 175 m3 of faecal sludge per year, thus 51.7% can be drained by truck (146 514 m3), either 401 m3/jour. Only 52.4% are collected and (210 m3/jour) and sent-on the site of unloading of NOMAYOS. La présente étude porte sur le traitement sur l’assainissement dans la parcelle et la quantification des boues de vidange dans la ville de Yaoundé. La population de la ville de Yaoundé 3,1 millions d’habitants en 2018, atteindra 4,7 millions en 2030 avec un taux de croissance moyen annuel de 3,5%. La ville de Yaoundé est dominée par un système d’assainissement autonome qui est utilisé par 99% des ménages. Les eaux usées domestiques de la ville sont principalement traitées par des systèmes d'assainissement autonomes représentés par des fosses septiques, des latrines à fosse traditionnelles, des latrines à fosse améliorée ventilées, etc. Une enquête a été effectuée auprès de 1100 ménages de la ville de Yaoundé. Le choix de ménage à enquêter a été faite selon la méthode stratifiée. Il est passé en revue, les méthodes de quantification des boues de vidange utilisées existantes, afin de choisir une méthode adaptée au contexte de la ville de Yaoundé. Plusieurs critères sont analysés pour évaluer l’accès aux boues produites par les ménages : l’existence ou non de voirie, leur état de dégradation, les types de l’ouvrage d’assainissement, la position de l’ouvrage par rapport aux voies d’accès etc. pour la quantification des boues de vidange. Parmi les méthodes de quantification des boues de vidanges explorées, nous avons trouvé que « la méthode production spécifique » est plus adaptée au contexte. Mais cette méthode a été revue afin d’intégrer les éléments d’analyse sur l’accessibilité des ouvrages d’assainissement. L’application de la méthode retenue a été faite sur 120 ouvrages d’assainissement vidangés entre Juin et juillet 2018, choisis au hasard sur le potentiel de 600 ouvrages vidangés dans la ville de Yaoundé pendant cette période. Le taux d’accumulation des boues de vidange dans la ville de Yaoundé est de 0,356 l/hab/jour pour les fosses septiques et 0.21 l/hab/jour pour les latrines. Il varie également en fonction de standing de l’habitat. A l’échelle de la ville, 41% des fosses uniques et 84% des fosses septiques peuvent être vidangées par camion. L’intervalle entre deux vidanges est de 7 ans en moyenne pour les fosses septiques et 10 ans pour les latrines. Au final, la ville de Yaoundé produit en 2018, 283 175 m3 de boues de vidange par an, dont 51,7% peuvent être vidangés par camion (146 514 m3), soit 401 m3/jour. Seuls 52,4% de la quantité vidangeable, sont collectés en 2018 (210 m3/jour) et acheminés sur le site de dépotage de NOMAYOS.

scholarly journals Estimation of fuel potential of faecal sludge in a water scarce city, a case study of Jaipur Urban, India

2020 ◽  
Vol 15 (2) ◽  
pp. 506-514
Author(s):  
Niharika Sharma ◽  
Sagar Gupta ◽  
Anil Dutt Vyas
Keyword(s):  
Heating Value ◽  
High Heating Value ◽  
Rural And Urban ◽  
Urban Level ◽  
Water Scarce ◽  
Sanitation Systems ◽  
The City ◽  
Different Sources ◽  
Faecal Sludge

Abstract Non-sewer sanitation systems are widely implemented for treatment and management of faecal sludge (FS) and septage in developing nations. India became an open defecation free (ODF) country in 2019, with more than 90 million toilets at rural and urban level constructed to achieve this ODF status. Government of India also initiated a faecal sludge and septage management (FSSM) policy in 2017. This paper highlights the policy vision for the state of Rajasthan and predicts options for a safely managed sanitation system through exploring the fuel potential of faecal sludge generated in the city. The intended study is an attempt to valorize faecal sludge into a marketable product through determining the heat capacity of dried faecal sludge from different sources such as pit toilets, septic tanks etc. In the present work in urban Jaipur, which is already a water scarce city, various onsite sanitation systems were targeted to collect FS samples from different locations. It was observed that the FS generated has a high heating value of 13.96 MJ/kg, with total solids ranges from 7 to 9%. For a pragmatic resource recovery option, the experimental data observed is validated with a literature review.

Integrated faecal sludge treatment and recycling through constructed wetlands and sunflower plant irrigation

2006 ◽  
Vol 54 (11-12) ◽  
pp. 155-164 ◽  
Author(s):  
T. Koottatep ◽  
C. Polprasert ◽  
S. Hadsoi
Keyword(s):  
Plant Biomass ◽  
Tap Water ◽  
Oxygen Demand ◽  
Application Rate ◽  
Solid Loading ◽  
Sunflower Plant ◽  
Increase With Increase ◽  
High Concentrations ◽  
Sanitation Systems ◽  
Faecal Sludge

Faecal sludge (FS) from the on-site sanitation systems is a nutrient-rich source but can contain high concentrations of toxic metals and chemicals and infectious micro-organisms. The study employed 3 vertical-flow CW units, each with a dimension of 5×5×0.65 m (width×length×media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/m2.yr and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80–96%. A solid layer of about 80 cm was found accumulated on the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation sunflower plant (Helianthus annuus) plots, each with a dimension of 4.5×4.5 m (width×length). In the study, tap water was mixed with 20%, 80% and 100% of the CW percolate at the application rate of 7.5 mm/day. Based on a 1-year data in which 3 crops of plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increase in CW percolate ratios. In a plot with 100% of CW percolate irrigation, the maximum Zn, Mn and Cu concentrations of 5.0, 12.3 and 2.5 mg/kg, respectively, were detected in the percolate-fed soil, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower were detected. The highest plant biomass yield and oil content of 1000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate.

scholarly journals Inhibition of Ammonia and Hydrogen Sulphide Using Plant Waste Materials for Faecal Sludge Odour Control in Dry Sanitation Toilet Facilities

2021 ◽  
Author(s):  
Bernice Mawumenyo Senanu ◽  
Patrick Boakye ◽  
Sampson Oduro-Kwarteng ◽  
Divine Damertey Sewu ◽  
Esi Awuah ◽  
...  
Keyword(s):  
Rice Husk ◽  
Hydrogen Sulphide ◽  
Cost Effective ◽  
Sub Saharan Africa ◽  
Open Defecation ◽  
Sub Saharan ◽  
Sanitation Systems ◽  
S Peak ◽  
Faecal Sludge ◽  
Peak Value

Abstract 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.

Treatment of domestic wastewater using conventional and baffled septic tanks

2013 ◽  
Vol 34 (16) ◽  
pp. 2337-2343 ◽  
Author(s):  
Fayza Aly Nasr ◽  
Basem Mikhaeil
Keyword(s):  
Domestic Wastewater ◽  
Septic Tanks

scholarly journals USE OF TREATED SEWAGE AS WATER AND A NUTRITIONAL SOURCE FOR BEAN CROPS

2018 ◽  
Vol 31 (2) ◽  
pp. 487-494 ◽  
Author(s):  
CLEY ANDERSON SILVA DE FREITAS ◽  
JOSÉ ADEILSON MEDEIROS DO NASCIMENTO ◽  
FRANCISCO MARCUS LIMA BEZERRA ◽  
RONNEY MENDES MAGALHÃES DE LIMA
Keyword(s):  
Potential Evapotranspiration ◽  
Block Design ◽  
Sewage Treatment ◽  
Domestic Wastewater ◽  
Water Source ◽  
Nutritional Recommendations ◽  
Randomized Block Design ◽  
Treated Sewage ◽  
Irrigation Levels ◽  
The City

ABSTRACT Considering the relevance of the reduction or replacement of fresh water supplies for irrigation, to mitigate the use of agricultural fertilizers and to improve sustainability, this study aimed to evaluate water and nutritional efficiency of treated sewage in cowpea plots. The experiment was conducted in the city of Tianguá-CE, on land belonging to the Water and Sewage Treatment Company of Ceará. It used a randomized block design for the arrangement of split plots. The plots contained two water sources (treated sewage and well water). The subplots contained four irrigation levels based on potential evapotranspiration (50%, 75%, 100%, and 125% of ETc) and the sub-subplots contained four nitrogen, phosphorous, and potassium (NPK) levels (0%, 33%, 66%, and 99% of the nutritional recommendations for cowpea cultivation). The yield variables, number of pods per plant, bean numbers per pod, and bean production, were improved with increased irrigation, regardless of the water source. Examining NPK levels in particular, yields differed depending on the water source. The use of treated domestic wastewater for bean irrigation can replace up to 100% of commercial fertilizers.

scholarly journals Off-Site Lime Stabilisation as an Option to Treat Pit Latrine Faecal Sludge for Emergency and Existing On-Site Sanitation Systems

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Wilson Greya ◽  
Bernard Thole ◽  
Catherine Anderson ◽  
Flavius Kamwani ◽  
Jan Spit ◽  
...  
Keyword(s):  
Large Scale ◽  
Buffer Capacity ◽  
Hydrated Lime ◽  
Field Trials ◽  
Small Scale ◽  
E Coli ◽  
Scale Field ◽  
Large Scale Field ◽  
Sanitation Systems ◽  
Faecal Sludge

Off-site lime stabilisation for treating faecal sludge was assessed by undertaking small-scale (35 L) and large-scale (600 L) field trials in Blantyre, Malawi. Hydrated lime was dosed to maintain pH 10, pH 10.5, pH 11, pH 11.5, and pH 12 depending on the buffer capacity of the faecal sludge in the four replica small-scale field trials. Significant reduction of E. coli to below the detection limit of 104 CFU/100 mL within 1 hour of treatment was reported for pH > 11. Based on the small-scale findings, large-scale field trials were conducted and greater than 3 log removal of E. coli was observed under pH 12 conditions. Therefore, based on the study, off-site lime stabilisation by dosing lime in the range of 10–35% w/w (dry solid basis), depending on the buffer capacity and solids content of the sludge to maintain pH > 11, can be used to sanitise faecal sludge during emergencies, as well as for existing on-site sanitation systems.

Evaluating the prevalence and nature of blat in post-Soviet societies

2014 ◽  
Vol 41 (9) ◽  
pp. 747-759 ◽  
Author(s):  
Colin C. Williams ◽  
Olga Onoshchenko
Keyword(s):  
Empirical Evaluation ◽  
Structured Interviews ◽  
Content Type ◽  
Face To Face ◽  
Goods And Services ◽  
Personal Connections ◽  
Stratified Sample ◽  
Nuanced Understanding ◽  
The City

Purpose – The purpose of this paper is to evaluate the extent to which the practice of using personal networks to obtain goods and services or to circumvent formal procedures, known as blat in the Soviet era, persists in post-Soviet societies and whether its character has altered. Design/methodology/approach – To do this, the prevalence and nature of blat in the education sector in the city of Mykolayiv in Ukraine is analysed using 200 face-to-face structured interviews with a spatially stratified sample of Mykolayiv residents and 30 follow-up semi-structured in-depth interviews. Findings – The finding is that blat is widely used to gain places in kindergarten, schools and universities. However, unlike Soviet era blat which took the form of non-monetised friendly help in the market-oriented society of post-Soviet Ukraine, both possessing control over access to assets such as education, as well as possessing personal connections to those with control over access to these assets, is increasingly viewed as a commodity to be bought and sold, and illicit informal monetary payments are now commonplace. The result is that nepotism, cronyism, bribery and corruption hinder meritocratic processes. Research limitations/implications – This paper examines the prevalence and nature of blat in just one sector in one post-Soviet country. An analysis across a wider range of sectors in various post-Soviet societies is now required to develop a more context-bound and nuanced understanding of blat in post-Soviet societies. Originality/value – This is the first in-depth empirical evaluation of the prevalence and nature of blat in contemporary post-Soviet societies.

Evaluation of sanitation and wastewater treatment technologies: case studies from India

2013 ◽  
Vol 3 (1) ◽  
pp. 1-11 ◽  
Author(s):  
M. Starkl ◽  
T. A. Stenström ◽  
E. Roma ◽  
M. Phansalkar ◽  
R. K. Srinivasan
Keyword(s):  
Wastewater Treatment ◽  
High Risk ◽  
Case Studies ◽  
Initial Assessment ◽  
Cultural Economic ◽  
Septic Tanks ◽  
Decentralized Wastewater Treatment ◽  
Treatment Technologies ◽  
Sanitation Systems ◽  
Wastewater Treatment Systems

This paper reports about the results of an evaluation of selected sanitation systems in India. The following sanitation systems were evaluated: septic tanks, communal Ecosan systems, biogas toilets, solid immobilized biofilters, multiple stage filtration and decentralized wastewater treatment systems (DEWATS). The evaluation has been based on an initial assessment looking at whether the systems comply with their intended benefits, and more in depth evaluations on cultural, economic and/or hygienic aspects where the initial assessment has not provided sufficient knowledge. The evaluation showed that all sanitation systems were well accepted by the users. The highest hygienic risk is present in septic tanks, where sludge handling poses a high risk for persons handling it.

Material flow analysis as a tool for sustainable sanitation planning in developing countries: case study of Arba Minch, Ethiopia

2009 ◽  
Vol 59 (10) ◽  
pp. 1911-1920 ◽  
Author(s):  
F. Meinzinger ◽  
K. Kröger ◽  
R. Otterpohl
Keyword(s):  
Technology Implementation ◽  
Material Flow ◽  
Flow Analysis ◽  
Material Flow Analysis ◽  
Nitrogen And Phosphorus ◽  
Urine Diversion ◽  
Sanitation Systems ◽  
The Impact ◽  
Faecal Sludge

Material Flow Analysis is a method that can be used to assess sanitation systems with regard to their environmental impacts. Modelling water and nutrients flows of the urban water, wastewater and waste system can highlight risks for environmental pollution and can help evaluating the potential for linking sanitation with resource recovery and agricultural production. This study presents the results of an analysis of nitrogen and phosphorus flows of Arba Minch town in South Ethiopia. The current situation is modelled and possible scenarios for upgrading the town's sanitation system are assessed. Two different scenarios for nutrient recovery are analysed. Scenario one includes co-composting municipal organic waste with faecal sludge from pit latrines and septic tanks as well as the use of compost in agriculture. The second scenario based on urine-diversion toilets includes application of urine as fertiliser and composting of faecal matter. In order to allow for variations in the rate of adoption, the model can simulate varying degrees of technology implementation. Thus, the impact of a step-wise or successive approach can be illustrated. The results show that significant amounts of plant nutrients can be provided by both options, co-composting and urine diversion.

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