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Phosphorus phyto-availability and fertilizer value of petrochemical and municipal wastewater sludges
Dissertation (MScAgric)--University of Pretoria, 2014.
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| Format: | Thesis |
| Language: | English |
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University of Pretoria
2015
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| _version_ | 1867613635212214272 |
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| access_status_str | Open Access |
| author2 | De Jager, Pieter Christiaan |
| author_browse | De Jager, Pieter Christiaan |
| author_facet | De Jager, Pieter Christiaan |
| collection | Thesis |
| dc_rights_str_mv | © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. |
| description | Dissertation (MScAgric)--University of Pretoria, 2014. |
| format | Thesis |
| id | oai:repository.up.ac.za:2263/46060 |
| institution | University of Pretoria (South Africa) |
| language | English |
| last_indexed | 2026-06-10T12:39:16.707Z |
| license_str | Other — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UPSpace — University of Pretoria Institutional Repository |
| publishDate | 2015 |
| publishDateRange | 2015 |
| publishDateSort | 2015 |
| publisher | University of Pretoria |
| publisherStr | University of Pretoria |
| record_format | dspace |
| source_str | UPSpace — University of Pretoria Institutional Repository |
| spelling | oai:repository.up.ac.za:2263/46060 Phosphorus phyto-availability and fertilizer value of petrochemical and municipal wastewater sludges De Jager, Pieter Christiaan Annandale, John George Van der Merwe, Petrus UCTD Ammonium phosphate Bray-1 Phosphate phyto-availability Relative phosphate fertilizer value % Municipal wastewater sludge Dissertation (MScAgric)--University of Pretoria, 2014. A growing population, urbanization and an increase in the number of industries is causing an increase in sewage sludge (SS) that needs to be either beneficially used or disposed of. Application of SS to agricultural lands is a well-known practice but the plant available phosphate and phosphate fertilizer value of SS has been of concern. This is especially due to the wide variety of soils that SS is applied to and the different phosphate removal processes that sewage waste water undergoes at the water care works and the source used to produce SS. Phosphate phyto-availability and phosphate fertilizer value of petrochemical and municipal wastewater sludges (SS) were determined in four different soils using an incubation study over 168 days, a pot trial over 42 days and a field trial over one season. Phosphate phyto-availability was determined/calculated by means of an incubation approach. Soils were incubated with sludge as well as mono ammonium phosphate (MAP). The soils were then subjected to a Bray-1 extraction after a certain time (42 days, 168 days). The relative phosphate fertilizer value (RPFV) was then expressed as a percentage of the Bray-1 extractability of the sludge-amended soil, relative to the MAP-amended soil. The influence of soil properties, especially clay content, and sludge properties namely phosphate extraction method (chemical and biological) from waste water stream, was investigated to determine the effect on phytoavailability and fertilizer value of phosphate in SS-amended soil. Soil properties were the dominant factor determining plant available phosphate, where plant available phosphate decreased with increasing clay content, irrelevant of the type of treatment. There were, however, significant differences between the chemical and biologically removed SS, where the biologically removed SS had higher plant available phosphate. The RPFV % of the SS was comparable to MAP in terms of its plant availability. Wetting and drying cycles in the pot trial influenced the plant available phosphate from the SS, where the chemically treated sludge showed in general lower plant availability. The RPFV % of the biologically removed phosphate sludges was better than that of MAP and that of the chemically phosphate removed sludge were lower. Application of all the different sludge types resulted in a positive reaction on plant available phosphate for all the soils. All the trials were conducted at pH of about 5.5. However, it is expected that biologically P removed sludge will perform better in acid soils. The reason being that ferric phosphate in the chemically treated sludge is less soluble under pH conditions lower than 5.5 than above it. tm2015 Plant Production and Soil Science MScAgric Unrestricted 2015-07-02T11:06:43Z 2015-07-02T11:06:43Z 2015/04/14 2014 Dissertation Van der Merwe, P 2014, Phosphorus phyto-availability and fertilizer value of petrochemical and municipal wastewater sludges, MScAgric Dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/46060> A2015 http://hdl.handle.net/2263/46060 en © 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria. application/pdf University of Pretoria |
| spellingShingle | UCTD Ammonium phosphate Bray-1 Phosphate phyto-availability Relative phosphate fertilizer value % Municipal wastewater sludge Phosphorus phyto-availability and fertilizer value of petrochemical and municipal wastewater sludges |
| title | Phosphorus phyto-availability and fertilizer value of petrochemical
and municipal wastewater sludges |
| title_full | Phosphorus phyto-availability and fertilizer value of petrochemical
and municipal wastewater sludges |
| title_fullStr | Phosphorus phyto-availability and fertilizer value of petrochemical
and municipal wastewater sludges |
| title_full_unstemmed | Phosphorus phyto-availability and fertilizer value of petrochemical
and municipal wastewater sludges |
| title_short | Phosphorus phyto-availability and fertilizer value of petrochemical
and municipal wastewater sludges |
| title_sort | phosphorus phyto availability and fertilizer value of petrochemical and municipal wastewater sludges |
| topic | UCTD Ammonium phosphate Bray-1 Phosphate phyto-availability Relative phosphate fertilizer value % Municipal wastewater sludge |
| url | http://hdl.handle.net/2263/46060 |