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The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal
Includes bibliographies.
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
Department of Civil Engineering
2016
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| _version_ | 1867613143681728512 |
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| access_status_str | Open Access |
| author | De Haas, David Walter |
| author_browse | De Haas, David Walter |
| author_facet | De Haas, David Walter |
| author_sort | De Haas, David Walter |
| collection | Thesis |
| description | Includes bibliographies. |
| format | Thesis |
| id | oai:open.uct.ac.za:11427/16090 |
| institution | University of Cape Town (South Africa) |
| language | eng |
| last_indexed | 2026-06-10T12:31:28.055Z |
| license_str | Not specified — see source repository |
| provenance_str_mv | Harvested via OAI-PMH from UCTD — University of Cape Town Open Access Repository |
| publishDate | 2016 |
| publishDateRange | 2016 |
| publishDateSort | 2016 |
| publisher | Department of Civil Engineering |
| publisherStr | Department of Civil Engineering |
| record_format | dspace |
| source_str | UCTD — University of Cape Town Open Access Repository |
| spelling | oai:open.uct.ac.za:11427/16090 The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal De Haas, David Walter Civil Engineering Includes bibliographies. Since its first full-scale implementation in the late 1970s, considerable practical experience has been gained with biological enhanced phosphate removal (BEPR) in activated sludge systems for treating wastewater. However, BEPR tends to be sensitive and subject to many fluctuations, making it difficult to achieve full compliance with discharge standards. Simultaneous chemical addition in the activated sludge systems is a practical and economically attractive means of increasing the phosphate (P) removal capacity of these systems. However, it is also clear that the economic benefit of building a BEPR system could be lost if simultaneous addition of chemicals results in significant inhibition of the biological P removal mechanism. In South Africa anecdotal evidence of such inhibition has emerged. In view of its fundamental importance to the design and operation of BEPR plants which incorporate simultaneous chemical addition, it was considered imperative that the impact of simultaneous chemical addition on the biological P removal mechanism be investigated further, particularly with a view to addressing possible outstanding questions arising from re-interpretation of earlier work. Experimental work was conducted using two identical pilot (or laboratory-scale) activated sludge plants operated such that the BEPR phenomenon was strongly exhibited. The two plants were operated in parallel under identical conditions. Chemical precipitant (aluminium sulphate, ferric chloride or ferrous chloride) was dosed into one plant (the Test unit), while the other served as Control. As a means of distinguishing the chemically-precipitated phosphate content of the mixed liquor from biologically-stored phosphate (or poly P) pool, methods for chemical fractionation of the phosphate compounds in activated sludge were investigated. A fractionation procedure was adopted which appeared to be capable of broadly distinguishing between chemical and biological forms of stored phosphorus in activated sludge and showed satisfactory agreement with the predicted results for BEPR obtained using a mathematical model of such systems. However, caution in interpretation of the fractionation data was advised since artefacts imposed by the fractionation procedure itself may be difficult to avoid. 2016-01-02T04:18:56Z 2016-01-02T04:18:56Z 1998 Doctoral Thesis Doctoral PhD http://hdl.handle.net/11427/16090 eng application/pdf Department of Civil Engineering Faculty of Engineering and the Built Environment University of Cape Town |
| spellingShingle | Civil Engineering De Haas, David Walter The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal |
| thesis_degree_str | Doctoral |
| title | The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal |
| title_full | The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal |
| title_fullStr | The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal |
| title_full_unstemmed | The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal |
| title_short | The use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal |
| title_sort | use of simultaneous chemical precipitation in modified activated sludge systems exhibiting biological enhanced phosphate removal |
| topic | Civil Engineering |
| url | http://hdl.handle.net/11427/16090 |
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