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Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors

In vitro methods were used to assess the full potential for decomposition (measured as biogas formation) from pit latrine samples taken from the top layer of 15 Tanzanian latrines. We found considerable variability in the decomposition rate and extent. This was compared with decomposition in the sam...

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Autores principales: van Eekert, Miriam H. A., Gibson, Walter T, Torondel, Belen, Abilahi, Faraji, Liseki, Bernard, Schuman, Els, Sumpter, Colin, Ensink, Jeroen H. J
Formato: Online Artículo Texto
Lenguaje:English
Publicado: IWA Publishing 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7797630/
https://www.ncbi.nlm.nih.gov/pubmed/31411578
http://dx.doi.org/10.2166/wst.2019.220
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author van Eekert, Miriam H. A.
Gibson, Walter T
Torondel, Belen
Abilahi, Faraji
Liseki, Bernard
Schuman, Els
Sumpter, Colin
Ensink, Jeroen H. J
author_facet van Eekert, Miriam H. A.
Gibson, Walter T
Torondel, Belen
Abilahi, Faraji
Liseki, Bernard
Schuman, Els
Sumpter, Colin
Ensink, Jeroen H. J
author_sort van Eekert, Miriam H. A.
collection PubMed
description In vitro methods were used to assess the full potential for decomposition (measured as biogas formation) from pit latrine samples taken from the top layer of 15 Tanzanian latrines. We found considerable variability in the decomposition rate and extent. This was compared with decomposition in the same latrines, measured by comparing top layer composition with fresh stools and deeper (older) layers, to assess whether this potential was realised in situ. Results showed a close match between the extent of organic material breakdown in situ and in vitro, indicating that anaerobic digestion is the dominant pathway in latrines. The average potential decrease in chemical oxygen demand (COD) (determined as methane production in vitro within 60 days) and actual measured decrease in situ are 68.9% ± 11.3 and 69.7% ± 19.4, respectively. However in the in vitro tests, where samples were diluted in water, full decomposition was achieved in 2 months, whereas in situ it can take years; this suggests that water addition may offer a simple route to improving latrine performance. The results also allowed us to estimate, for the first time to our knowledge using experimental data, the contribution that latrines make to greenhouse gas emissions globally.This amounts to ∼2% of annual US emissions.
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spelling pubmed-77976302021-02-12 Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors van Eekert, Miriam H. A. Gibson, Walter T Torondel, Belen Abilahi, Faraji Liseki, Bernard Schuman, Els Sumpter, Colin Ensink, Jeroen H. J Water Sci Technol Editor's Choice In vitro methods were used to assess the full potential for decomposition (measured as biogas formation) from pit latrine samples taken from the top layer of 15 Tanzanian latrines. We found considerable variability in the decomposition rate and extent. This was compared with decomposition in the same latrines, measured by comparing top layer composition with fresh stools and deeper (older) layers, to assess whether this potential was realised in situ. Results showed a close match between the extent of organic material breakdown in situ and in vitro, indicating that anaerobic digestion is the dominant pathway in latrines. The average potential decrease in chemical oxygen demand (COD) (determined as methane production in vitro within 60 days) and actual measured decrease in situ are 68.9% ± 11.3 and 69.7% ± 19.4, respectively. However in the in vitro tests, where samples were diluted in water, full decomposition was achieved in 2 months, whereas in situ it can take years; this suggests that water addition may offer a simple route to improving latrine performance. The results also allowed us to estimate, for the first time to our knowledge using experimental data, the contribution that latrines make to greenhouse gas emissions globally.This amounts to ∼2% of annual US emissions. IWA Publishing 2019-06-25 /pmc/articles/PMC7797630/ /pubmed/31411578 http://dx.doi.org/10.2166/wst.2019.220 Text en © 2019 The Authors http://creativecommons.org/licenses/by/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Editor's Choice
van Eekert, Miriam H. A.
Gibson, Walter T
Torondel, Belen
Abilahi, Faraji
Liseki, Bernard
Schuman, Els
Sumpter, Colin
Ensink, Jeroen H. J
Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors
title Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors
title_full Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors
title_fullStr Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors
title_full_unstemmed Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors
title_short Anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors
title_sort anaerobic digestion is the dominant pathway for pit latrine decomposition and is limited by intrinsic factors
topic Editor's Choice
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7797630/
https://www.ncbi.nlm.nih.gov/pubmed/31411578
http://dx.doi.org/10.2166/wst.2019.220
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