TY - JOUR
T1 - Preliminary study on the potential use of fly ash as a ventilated improved pit latrine additive
AU - Collings, Dylan
AU - Tandlich, Roman
AU - Dube, Cyril S.
AU - Madikizela, Phindile
AU - Ngqwala, Nosiphiwe P.
AU - Ahmed, Mushtaque
N1 - Funding Information:
The authors would like to acknowledge the National Research Foundation of South Africa and the Rhodes University Biotechnology Innovation Centre (RUBIC) are acknowledged for funding the study in part.
Publisher Copyright:
© 2019 Widener University School of Civil Engineering. All rights reserved.
PY - 2019/11
Y1 - 2019/11
N2 - 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.
AB - 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.
KW - Community of practice
KW - Faecal coliforms
KW - Improved sanitation
KW - Leachable chemical components
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U2 - 10.5276/JSWTM/2019.395
DO - 10.5276/JSWTM/2019.395
M3 - Article
AN - SCOPUS:85091185863
SN - 1088-1697
VL - 45
SP - 395
EP - 402
JO - Journal of Solid Waste Technology and Management
JF - Journal of Solid Waste Technology and Management
IS - 4
ER -