Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| On the acid-base stability of Keggin Al-13 and Al-30 polymers in polyaluminum coagulants | |
Chen, Zhaoyang1; Luan, Zhaokun2; Jia, Zhiping2; Li, Xiaosen1
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| 2009-06-01 | |
| Source Publication | JOURNAL OF MATERIALS SCIENCE
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| ISSN | 0022-2461 |
| Volume | 44Issue:12Pages:3098-3111 |
| Corresponding Author | chenzy@ms.giec.ac.cn ; lixs@ms.giec.ac.cn |
| Abstract | The acid-base stabilities of Al-13 and Al-30 in polyaluminum coagulants during aging and after dosing into water were studied systematically using batch and flow-through acid-base titration experiments. The acid decomposition rates of both Al-13 and Al-30 increase rapidly with the decrease in solution pH. The acid decompositions of Al-13 and Al-30 with respect to H+ concentration are composed of two parallel first-order and second-order reactions, and the reaction orders are 1.169 and 1.005, respectively. The acid decomposition rates of Al-13 and Al-30 increase slightly when the temperature increases from 20 to ca. 35 A degrees C, but decrease when the temperature increases further. Al-30 is more stable than Al-13 in acidic solution, and the stability difference increases as the pH decreases. Al-30 is more possible to become the dominant species in polyaluminum coagulants than Al-13. The acid catalyzed decomposition and followed by recrystallization to form bayerite is one of the main processes that are responsible for the decrease of Al-13 and Al-30 in polyaluminum coagulants during storage. The deprotonation and polymerization of Al-13 and Al-30 depend on solution pH. The hydrolysis products are positively charged, and consist mainly of repeated Al-13 and Al-30 units rather than amorphous Al(OH)(3) precipitates. Al-30 is less stable than Al-13 upon alkaline hydrolysis. Al-13 is stable at pH < 5.9, while Al-30 lose one proton at the pH 4.6-5.75. Al-13 and Al-30 lose respective 5 and 10 protons and form [Al-13] (n) and [Al-30] (n) clusters within the pH region of 5.9-6.25 and 5.75-6.65, respectively. This indicates that Al-30 is easier to aggregate than Al-13 at the acidic side, but [Al-13] (n) is much easier to convert to Alsol-gel than [Al-30] (n) . Al-30 possesses better characteristics than Al-13 when used as coagulant because the hydrolysis products of Al-30 possess higher charges than that of Al-13, and [Al-30] (n) clusters exist within a wider pH range. |
| Subtype | Article |
| Other Abstract | The acid-base stabilities of Al-13 and Al-30 in polyaluminum coagulants during aging and after dosing into water were studied systematically using batch and flow-through acid-base titration experiments. The acid decomposition rates of both Al-13 and Al-30 increase rapidly with the decrease in solution pH. The acid decompositions of Al-13 and Al-30 with respect to H+ concentration are composed of two parallel first-order and second-order reactions, and the reaction orders are 1.169 and 1.005, respectively. The acid decomposition rates of Al-13 and Al-30 increase slightly when the temperature increases from 20 to ca. 35 A degrees C, but decrease when the temperature increases further. Al-30 is more stable than Al-13 in acidic solution, and the stability difference increases as the pH decreases. Al-30 is more possible to become the dominant species in polyaluminum coagulants than Al-13. The acid catalyzed decomposition and followed by recrystallization to form bayerite is one of the main processes that are responsible for the decrease of Al-13 and Al-30 in polyaluminum coagulants during storage. The deprotonation and polymerization of Al-13 and Al-30 depend on solution pH. The hydrolysis products are positively charged, and consist mainly of repeated Al-13 and Al-30 units rather than amorphous Al(OH)(3) precipitates. Al-30 is less stable than Al-13 upon alkaline hydrolysis. Al-13 is stable at pH < 5.9, while Al-30 lose one proton at the pH 4.6-5.75. Al-13 and Al-30 lose respective 5 and 10 protons and form [Al-13] (n) and [Al-30] (n) clusters within the pH region of 5.9-6.25 and 5.75-6.65, respectively. This indicates that Al-30 is easier to aggregate than Al-13 at the acidic side, but [Al-13] (n) is much easier to convert to Alsol-gel than [Al-30] (n) . Al-30 possesses better characteristics than Al-13 when used as coagulant because the hydrolysis products of Al-30 possess higher charges than that of Al-13, and [Al-30] (n) clusters exist within a wider pH range. |
| Keyword | Al13 Tridecameric Polycation Aqueous-solution Aluminum Transformation Chemistry Polyoxocations Complexes Al-13-cluster Hydrolysis Speciation |
| WOS Headings | Science & Technology ; Technology |
| DOI | 10.1007/s10853-009-3412-0 |
| WOS Subject Extended | Materials Science |
| URL | 查看原文 |
| WOS Keyword | AL13 TRIDECAMERIC POLYCATION ; AQUEOUS-SOLUTION ; ALUMINUM ; TRANSFORMATION ; CHEMISTRY ; POLYOXOCATIONS ; COMPLEXES ; AL-13-CLUSTER ; HYDROLYSIS ; SPECIATION |
| Indexed By | SCI |
| Language | 英语 |
| Funding Organization | National High Technology Research and Development Key Program of China [2002AA601290]; National Natural Science Foundation of China [50874098, 40673003] |
| WOS Subject | Materials Science, Multidisciplinary |
| WOS ID | WOS:000266039000013 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/3344 |
| Collection | 中国科学院广州能源研究所 |
| Affiliation | 1.Chinese Acad Sci, Key Lab Renewable Energy & Gas Hydrate, Guangzhou Inst Energy Convers, Guangzhou 510640, Peoples R China 2.Chinese Acad Sci, State Key Lab Environm Aquat Chem, Res Ctr Ecoenvironm Sci, Beijing 100085, Peoples R China |
| Recommended Citation GB/T 7714 | Chen, Zhaoyang,Luan, Zhaokun,Jia, Zhiping,et al. On the acid-base stability of Keggin Al-13 and Al-30 polymers in polyaluminum coagulants[J]. JOURNAL OF MATERIALS SCIENCE,2009,44(12):3098-3111. |
| APA | Chen, Zhaoyang,Luan, Zhaokun,Jia, Zhiping,&Li, Xiaosen.(2009).On the acid-base stability of Keggin Al-13 and Al-30 polymers in polyaluminum coagulants.JOURNAL OF MATERIALS SCIENCE,44(12),3098-3111. |
| MLA | Chen, Zhaoyang,et al."On the acid-base stability of Keggin Al-13 and Al-30 polymers in polyaluminum coagulants".JOURNAL OF MATERIALS SCIENCE 44.12(2009):3098-3111. |
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