Key issues to consider when using alum sludge as substrate in constructed wetland
Globally, alum sludge is an easily, locally and largely available by-product from water treatment plants where aluminium sulphate is used as the coagulant for raw water purification. Owing to the high content of Al ions (29.7±13.3% dry weight) in alum sludge and the strong affinity of Al ions to ads...
| Veröffentlicht in: | Water science and technology : a journal of the International Association on Water Pollution Research. - 1986. - 71(2015), 12 vom: 19., Seite 1775-82 |
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| Weitere Verfasser: | , , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | Water science and technology : a journal of the International Association on Water Pollution Research |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't Alum Compounds Sewage Water Pollutants, Chemical Phosphorus 27YLU75U4W aluminum sulfate 34S289N54E Aluminum |
| Zusammenfassung: | Globally, alum sludge is an easily, locally and largely available by-product from water treatment plants where aluminium sulphate is used as the coagulant for raw water purification. Owing to the high content of Al ions (29.7±13.3% dry weight) in alum sludge and the strong affinity of Al ions to adsorb various pollutants especially phosphorus (P), alum sludge (in the form of dewatered cakes) has been investigated in recent years as a low-cost alternative substrate in constructed wetland (CW) systems to enhance the treatment efficiency especially for high strength P-containing wastewater. Long-term trials in different scales have demonstrated that the alum sludge-based CW is a promising technique with a two-pronged feature of using 'waste' for wastewater treatment. Alum sludge cakes in CW can serve as a medium for wetland plant growth, as a carrier for biofilm development and as a porous material for wastewater infiltration. After the intensive studies of the alum sludge-based CW system, this paper aims to address the key issues and concerns pertaining to this kind of CW system. These include: (1) Is alum sludge suitable for reuse in CWs? (2) Is Al released from the sludge a concern? (3) What is the lifespan of the alum sludge in CWs? (4) How can P be recovered from the used alum sludge? (5) Does clogging happen in alum sludge-based CW systems and what is the solution? |
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| Beschreibung: | Date Completed 09.11.2015 Date Revised 02.12.2018 published: Print Citation Status MEDLINE |
| ISSN: | 1996-9732 |
| DOI: | 10.2166/wst.2015.138 |