Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions
Globally, many populations suffer from a lack of access to basic sanitation facilities. This is partly caused by a combination of water resource shortages and the high cost of conventional centralised treatment systems. A novel decentralised treatment technology based on sub-critical hydrothermal pr...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2022-06-01
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| Series: | Heliyon |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405844022009963 |
| _version_ | 1811239394639609856 |
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| author | Gerty J.H.P. Gielen John P. Andrews Christine M. Karbiwnyk Mark J.C. Riddell Sean W. Husheer Daniel J. Gapes |
| author_facet | Gerty J.H.P. Gielen John P. Andrews Christine M. Karbiwnyk Mark J.C. Riddell Sean W. Husheer Daniel J. Gapes |
| author_sort | Gerty J.H.P. Gielen |
| collection | DOAJ |
| description | Globally, many populations suffer from a lack of access to basic sanitation facilities. This is partly caused by a combination of water resource shortages and the high cost of conventional centralised treatment systems. A novel decentralised treatment technology based on sub-critical hydrothermal processing of organic wastes at toilet-scale, contributes to addressing these economic and resource limitations. To be effective, this technology needs to satisfy a broad range of environmental and safety considerations, including the nature and quantity of formed gas products. We investigated the impact of four process parameters (temperature; O2: COD ratio (λ); time; feed solids content) on off-gas composition by quantifying volatile organic compounds (VOCs), CO, H2 and CO2 in factorial experiments. Temperature and λ influenced VOCs generation greatly. The lowest VOC emissions occurred at 200% λ and 300 °C. Aldehydes and ketones were mostly generated at 200% λ and intermediate temperatures, sulphur compounds in the absence of oxygen, and aromatics, furans, and pyrroles at intermediate oxygen levels and elevated temperatures. Most CO was created at 300 °C but its concentration decreased at longer processing times. Processing conditions have complex impacts and require careful consideration when designing for real world deployment. |
| first_indexed | 2024-04-12T12:59:15Z |
| format | Article |
| id | doaj.art-58115f2f54e844108f0ce89ca1a3f79b |
| institution | Directory Open Access Journal |
| issn | 2405-8440 |
| language | English |
| last_indexed | 2024-04-12T12:59:15Z |
| publishDate | 2022-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Heliyon |
| spelling | doaj.art-58115f2f54e844108f0ce89ca1a3f79b2022-12-22T03:32:13ZengElsevierHeliyon2405-84402022-06-0186e09708Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissionsGerty J.H.P. Gielen0John P. Andrews1Christine M. Karbiwnyk2Mark J.C. Riddell3Sean W. Husheer4Daniel J. Gapes5Corresponding author.; Scion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New ZealandScion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New ZealandScion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New ZealandScion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New ZealandScion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New ZealandScion, Titokorangi Drive, Private Bag 3020, Rotorua 3046, New ZealandGlobally, many populations suffer from a lack of access to basic sanitation facilities. This is partly caused by a combination of water resource shortages and the high cost of conventional centralised treatment systems. A novel decentralised treatment technology based on sub-critical hydrothermal processing of organic wastes at toilet-scale, contributes to addressing these economic and resource limitations. To be effective, this technology needs to satisfy a broad range of environmental and safety considerations, including the nature and quantity of formed gas products. We investigated the impact of four process parameters (temperature; O2: COD ratio (λ); time; feed solids content) on off-gas composition by quantifying volatile organic compounds (VOCs), CO, H2 and CO2 in factorial experiments. Temperature and λ influenced VOCs generation greatly. The lowest VOC emissions occurred at 200% λ and 300 °C. Aldehydes and ketones were mostly generated at 200% λ and intermediate temperatures, sulphur compounds in the absence of oxygen, and aromatics, furans, and pyrroles at intermediate oxygen levels and elevated temperatures. Most CO was created at 300 °C but its concentration decreased at longer processing times. Processing conditions have complex impacts and require careful consideration when designing for real world deployment.http://www.sciencedirect.com/science/article/pii/S2405844022009963HydrothermalToilet wasteWet oxidationVolatile organic compoundsCarbon monoxideDecentralised sanitation |
| spellingShingle | Gerty J.H.P. Gielen John P. Andrews Christine M. Karbiwnyk Mark J.C. Riddell Sean W. Husheer Daniel J. Gapes Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions Heliyon Hydrothermal Toilet waste Wet oxidation Volatile organic compounds Carbon monoxide Decentralised sanitation |
| title | Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions |
| title_full | Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions |
| title_fullStr | Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions |
| title_full_unstemmed | Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions |
| title_short | Hydrothermal conversion of toilet waste: effect of processing conditions on gas phase emissions |
| title_sort | hydrothermal conversion of toilet waste effect of processing conditions on gas phase emissions |
| topic | Hydrothermal Toilet waste Wet oxidation Volatile organic compounds Carbon monoxide Decentralised sanitation |
| url | http://www.sciencedirect.com/science/article/pii/S2405844022009963 |
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