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Optimising ventilation to control odour in the ventilated improved pit latrine

  • Peter A. Obeng
  • Sampson Oduro-Kwarteng
  • Bernard Keraita
  • Henrik Bregnhøj
  • Robert C. Abaidoo
  • Esi Awuah
  • Flemming Konradsen
Original Article
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Abstract

The rate of ventilation through the vent pipe of a ventilated improved pit latrine is the main technical factor that determines its efficiency in odour control aside the maintenance and cleaning practices of the users. Even though the factors affecting the ventilation rate have been well researched, they have not been previously related in a mathematical model to quantify the relative effect of the various factors on the ventilation rate. The objective of this paper is to develop such a model that could be used to optimise and predict the ventilation rate as a function of relevant design criteria and weather conditions. The ventilation rates produced by various design modifications in an experimental ventilated improved pit latrine were measured under monitored weather conditions. A linear regression model was used to assess the relative effect of the various design modifications and the elements of weather on the ventilation rate. It was found that the diameter of the vent pipe is the most important factor which accounts for 53% of variations in the ventilation rate, followed by the external wind speed, which accounts for 25% of changes in ventilation. The provision of windows in other sides of the superstructure other than the windward side leads to a reduction of 32% in the ventilation rate and accounts for 9% of the variations in the ventilation rate. A regression model developed in this study could be used to optimise and predict the ventilation rate based on a set of design criteria and meteorological data.

Keywords

VIP latrine Ventilated improved pit Ventilation rate Dry sanitation technology Modelling 
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Notes

Acknowledgements

This research was funded by the Danish International Development Agency (Grant number FFU-10-050KU). The Agency played no direct role in the conduct of the research and the views expressed in this paper do not necessarily reflect its views. The authors are also grateful to our field assistant, Mr. Eric Mensah Nukunu, for his diligent monitoring of the experimental setup.

Compliance with ethical standards

Conflict of interest

The author(s) declare that they have no competing interests.

References

  1. Appiah EO, Oduro-Kwarteng S (2011) Households’ perception of community toilets in low-income communities in Kumasi. In: Paper presented at the 3rd Ghana water forum: water and sanitation services delivery in a rapidly changing urban environment, 5–7 Sept 2011, AccraGoogle Scholar
  2. Autodesk Sustainability Workshop (2011) Stack ventilation and Bernoulli’s principle. http://sustainabilityworkshop.autodesk.com/buildings/stack-ventilation-and-bernoullis-principle. Accessed 2 May 2015
  3. Awbi HB (1994) Design considerations for naturally ventilated buildings. Renew Energy 5(II):1081–1090CrossRefGoogle Scholar
  4. Brikké F, Bredero M (2003) Linking technology choice with operation and maintenance in the context of community water supply and sanitation: a reference document for planners and project staff. WHO and IRC Water and Sanitation Centre. http://www.who.int/water_sanitation_health/hygiene/om/wsh9241562153.pdf/. Accessed 21 Nov 2015
  5. Darby R (2001) Chemical engineering fluid mechanics, 2nd edn. Marcel Dekker, Inc., New YorkGoogle Scholar
  6. Franceys R, Pickford J, Reed R (1992) A guide to the development of on-site sanitation. World Health Organization. http://www.who.int/water_sanitation_health/hygiene/envsan/onsitesan.pdf. Accessed 28 Jul 2014
  7. Harvey P, Baghri S, Reeb B (2002) Emergency sanitation: assessment and programme design. Water, Engineering and Development Centre. http://www.unicefinemergencies.com/downloads/eresource/docs/WASH/Emergency%20Sanitation%20(WEDC).pdf. Accessed 25 Aug 2015
  8. Kalbermatten JM, Julius DS, Gunnerson CG (1980) Appropriate technology for water and sanitation: technical and economic options. The International Bank for Reconstruction and Development and the World Bank. http://documents.worldbank.org/curated/en/929641467989573003/pdf/11508000Approp0te0of0the0art0review.pdf/. Accessed 21 Jul 2015
  9. Karnib A (2014) A methodological approach for quantitative assessment of the effective wastewater management: Lebanon as a case study. Environ Process 1(4):483–495.  https://doi.org/10.1007/s40710-014-0032-8 CrossRefGoogle Scholar
  10. Keraita B, Kjær P, Jensen M, Konradsen F, Akple M, Rheinländer T (2013) Accelerating uptake of household latrines in rural communities in the Volta region of Ghana. J Water Sanit Hyg Dev 03.1:26–34.  https://doi.org/10.2166/washdev.2013.035 CrossRefGoogle Scholar
  11. Kvarnstrom E, McConville J, Bracken P, Johansson M, Fogde M (2011) The sanitation ladder—a need for a revamp? J Water Sanit Hyg Dev.  https://doi.org/10.2166/washdev.2011.014 CrossRefGoogle Scholar
  12. Lenton R, Wright A (2005) Unpacking definitions—the MDG target on sanitation. Millennium Development Taskforce on Water and Sanitation. http://siteresources.worldbank.org/EXTWAT/Resources/4602122-1213366294492/5106220-1213366309673/2.1Unpacking_Definitions_MDGTargetonSanitation.pdf. Accessed 22 Dec 2016
  13. Mara DD (1984) The design of ventilated improved pit latrines. Technology Advisory Group Technical Note No. 13. The International Bank for Reconstruction and Development and The World Bank. https://www.google.com.gh/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwjl0dWDhdDXAhXFO5oKHUUdCC0QFggkMAA&url=http%3A%2F%2Fdocuments.worldbank.org%2Fcurated%2Fen%2F618101468749362028%2Fpdf%2Fmulti0page.pdf&usg=AOvVaw1_ErXwHi4SYXjVYCh90Xb6/. Accessed 20 May 2013
  15. Nau R (2014) Notes on linear regression analysis. Duke University. http://people.duke.edu/~rnau/testing.htm. Accessed 24 Apr 2015
  16. Ningo Prampram District Assembly (2012) Socio-Economic database. Ningo Prampram District Assembly, PrampramGoogle Scholar
  17. Obeng PA (2016) Usage barriers and improvement of the improved pit latrine for use in peri-urban settings of Ghana. Doctoral dissertation, Kwame Nkrumah University of Science and TechnologyGoogle Scholar
  18. Obeng PA, Keraita B, Oduro-Kwarteng S, Bregnhøj H, Abaidoo RC, Awuah E, Konradsen F (2015) Usage and barriers to use of latrines in a Ghanaian peri-urban community. Environ Process 2:261–274.  https://doi.org/10.1007/s40710-015-0060-z CrossRefGoogle Scholar
  19. Obeng PA, Keraita B, Oduro-Kwarteng S, Bregnhoj H, Abaidoo RC, Awuah E, Konradsen F (2016) Measurement of odour in on-site sanitation systems in low-income settings. Environ Process 3:217–227.  https://doi.org/10.1007/s40710-016-0124-8 CrossRefGoogle Scholar
  20. Paterson C, Mara D, Curtis T (2007) Pro-poor sanitation technologies. Geoforum 38:901–907CrossRefGoogle Scholar
  23. Simon G (2003) Multiple regression basics. New York University. http://people.stern.nyu.edu/wgreene/Statistics/MultipleRegressionBasicsCollection.pdf. Accessed 16 Jan 2015
  24. Simon G (2005) Multiple linear regression in Minitab. New York University. http://pages.stern.nyu.edu/~gsimon/RegannA14NOV05Refresh21OCT10.pdf. Accessed 27 Apr 2016
  25. Wiles F (2013) Understanding statistical intervals: Part 2 – prediction intervals. Propharma Group. http://www.propharmagroup.com/blog/understanding-statistical-intervals-part-2-prediction-intervals
  26. Wong NH, Heryanto S (2004) The study of active stack effect to enhance natural ventilation using wind tunnel and computational fluid dynamics (CFD) simulations. Energy Build 36:668–678CrossRefGoogle Scholar
  27. World Health Organisation (2000) Air quality guidelines, 2nd edn. WHO Regional Office for Europe, CopenhagenGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2018

Authors and Affiliations

  • Peter A. Obeng
    • 1
  • Sampson Oduro-Kwarteng
    • 2
  • Bernard Keraita
    • 3
  • Henrik Bregnhøj
    • 3
  • Robert C. Abaidoo
    • 4
  • Esi Awuah
    • 2
  • Flemming Konradsen
    • 3
  1. 1.Water and Sanitation Unit, Department of ChemistryUniversity of Cape CoastCape CoastGhana
  2. 2.Civil Engineering DepartmentKwame Nkrumah University of Science and TechnologyKumasiGhana
  3. 3.Department of Public HealthUniversity of CopenhagenCopenhagenDenmark
  4. 4.Department of Theoretical and Applied BiologyKwame Nkrumah University of Science and TechnologyKumasiGhana

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