Knowledge Management System Of Guangzhou Institute of Energy Conversion, CAS
| Study on the hydrolysis/precipitation behavior of Keggin Al-13 and Al-30 polymers in polyaluminum solutions | |
| Chen, Zhaoyang1; Luan, Zhaokun2; Jia, Zhiping2; Li, Xiaosen1 | |
| 2009-06-01 | |
| Source Publication | JOURNAL OF ENVIRONMENTAL MANAGEMENT
 |
| ISSN | 0301-4797 |
| Volume | 90Issue:8Pages:2831-2840 |
| Corresponding Author | chenzy@ms.giec.ac.cn ; lixs@ms.giec.ac.cn |
| Abstract | The hydrolysis/precipitation behaviors of Al3+, Al-13 and Al-30 under conditions typical for flocculation in water treatment were investigated by studying the particulates' size development, charge characteristics, chemical species and speciation transformation of coagulant hydrolysis precipitates. The optimal pH conditions for hydrolysis precipitates formation for AlCl3, PAC(A113) and PAC(A130) were 6.5-7.5, 8.5-9.5, and 7.5-9.5, respectively. The precipitates' formation rate increased with the increase in dosage, and the relative rates were AlCl3 >> PAC(A130) > PACA113. The precipitates' size increased when the dosage increased from 50 mu M to 200 mu M, but it decreased when the dosage increased to 800 AM. The Zeta potential of coagulant hydrolysis precipitates decreased with the increase in pH for the three coagulants. The isoelectric points of the freshly formed precipitates for AlCl3, PAC(A113) and PAC(A130) were 7.3, 9.6 and 9.2, respectively. The Zeta potentials of AlCl3 hydrolysis precipitates were lower than those of PAC(A113) and PAC(A130) when pH > 5.0. The Zeta potential of PAC(A130) hydrolysis precipitates was higher than that of PACA113 at the acidic side, but lower at the alkaline side. The dosage had no obvious effect on the Zeta potential of hydrolysis precipitates under fixed pH conditions. The increase in Zeta potential with the increase in dosage under uncontrolled pH conditions was due to the pH depression caused by coagulant addition. Al-Ferron research indicated that the hydrolysis precipitates of AlCl3 were composed of amorphous AI(OH)3 precipitates, but those of PACA113 and PACA130 were composed of aggregates of Al-13 and Al-30, respectively. Al3+ was the most un-stable species in coagulants, and its hydrolysis was remarkably influenced by solution pH. Al-13 and Al-30 species were very stable, and solution pH and aging had little effect on the chemical species of their hydrolysis products. The research method involving coagulant hydrolysis precipitates based on Al-Ferron reaction kinetics was studied in detail. The Al species classification based on complex reaction kinetic of hydrolysis precipitates and Ferron reagent was different from that measured in a conventional coagulant assay using the Al--Ferron method. The chemical composition of Al-a, Al-b and Al-c depended on coagulant and solution pH. The Al-b measured in the current case was different from Keggin Al-13, and the high Alb content in the AlCl3 hydrolysis precipitates could not used as testimony that most of the Al3+ Was converted to highly charged Al-13 species during AlCl3 coagulation. (C) 2009 Elsevier Ltd. All rights reserved. |
| Subtype | Article |
| Other Abstract | The hydrolysis/precipitation behaviors of Al3+, Al-13 and Al-30 under conditions typical for flocculation in water treatment were investigated by studying the particulates' size development, charge characteristics, chemical species and speciation transformation of coagulant hydrolysis precipitates. The optimal pH conditions for hydrolysis precipitates formation for AlCl3, PAC(A113) and PAC(A130) were 6.5-7.5, 8.5-9.5, and 7.5-9.5, respectively. The precipitates' formation rate increased with the increase in dosage, and the relative rates were AlCl3 >> PAC(A130) > PACA113. The precipitates' size increased when the dosage increased from 50 mu M to 200 mu M, but it decreased when the dosage increased to 800 AM. The Zeta potential of coagulant hydrolysis precipitates decreased with the increase in pH for the three coagulants. The isoelectric points of the freshly formed precipitates for AlCl3, PAC(A113) and PAC(A130) were 7.3, 9.6 and 9.2, respectively. The Zeta potentials of AlCl3 hydrolysis precipitates were lower than those of PAC(A113) and PAC(A130) when pH > 5.0. The Zeta potential of PAC(A130) hydrolysis precipitates was higher than that of PACA113 at the acidic side, but lower at the alkaline side. The dosage had no obvious effect on the Zeta potential of hydrolysis precipitates under fixed pH conditions. The increase in Zeta potential with the increase in dosage under uncontrolled pH conditions was due to the pH depression caused by coagulant addition. Al-Ferron research indicated that the hydrolysis precipitates of AlCl3 were composed of amorphous AI(OH)3 precipitates, but those of PACA113 and PACA130 were composed of aggregates of Al-13 and Al-30, respectively. Al3+ was the most un-stable species in coagulants, and its hydrolysis was remarkably influenced by solution pH. Al-13 and Al-30 species were very stable, and solution pH and aging had little effect on the chemical species of their hydrolysis products. The research method involving coagulant hydrolysis precipitates based on Al-Ferron reaction kinetics was studied in detail. The Al species classification based on complex reaction kinetic of hydrolysis precipitates and Ferron reagent was different from that measured in a conventional coagulant assay using the Al--Ferron method. The chemical composition of Al-a, Al-b and Al-c depended on coagulant and solution pH. The Al-b measured in the current case was different from Keggin Al-13, and the high Alb content in the AlCl3 hydrolysis precipitates could not used as testimony that most of the Al3+ Was converted to highly charged Al-13 species during AlCl3 coagulation. |
| Keyword | Al-13 And Al-30 Species Coagulant Ferron Method Chemical Speciation Zeta Potential |
| WOS Headings | Science & Technology ; Life Sciences & Biomedicine |
| DOI | 10.1016/j.jenvman.2009.04.001 |
| WOS Subject Extended | Environmental Sciences & Ecology |
| URL | 查看原文 |
| WOS Keyword | NUCLEAR-MAGNETIC-RESONANCE ; AQUEOUS-SOLUTION ; CHARGE NEUTRALIZATION ; WATER-TREATMENT ; COAGULATION ; HYDROLYSIS ; POLYCATION ; TRANSFORMATION ; PRECIPITATION ; SPECIATION |
| Indexed By | SCI |
| Language | 英语 |
| Funding Organization | National Natural Science Foundation of China [50874098, 40673003]; National High Technology Research and Development Key Program of China (863 Program) [2002AA601290] |
| WOS Subject | Environmental Sciences |
| WOS ID | WOS:000267453100058 |
| Citation statistics | |
| Document Type | 期刊论文 |
| Identifier | http://ir.giec.ac.cn/handle/344007/3318 |
| Collection | 中国科学院广州能源研究所 |
| Affiliation | 1.Chinese Acad Sci, CAS, Guangzhou Inst Energy Convers, Key Lab Renewable Energy & Gas Hydrate, Guangzhou 510640, Peoples R China 2.Chinese Acad Sci, Ecoenvironm Sci Res Ctr, State Key Lab Environm Aquat Chem, Beijing 100085, Peoples R China |
| Recommended Citation GB/T 7714 | Chen, Zhaoyang,Luan, Zhaokun,Jia, Zhiping,et al. Study on the hydrolysis/precipitation behavior of Keggin Al-13 and Al-30 polymers in polyaluminum solutions[J]. JOURNAL OF ENVIRONMENTAL MANAGEMENT,2009,90(8):2831-2840. |
| APA | Chen, Zhaoyang,Luan, Zhaokun,Jia, Zhiping,&Li, Xiaosen.(2009).Study on the hydrolysis/precipitation behavior of Keggin Al-13 and Al-30 polymers in polyaluminum solutions.JOURNAL OF ENVIRONMENTAL MANAGEMENT,90(8),2831-2840. |
| MLA | Chen, Zhaoyang,et al."Study on the hydrolysis/precipitation behavior of Keggin Al-13 and Al-30 polymers in polyaluminum solutions".JOURNAL OF ENVIRONMENTAL MANAGEMENT 90.8(2009):2831-2840. |
| Files in This Item: | Download All | |||||
| File Name/Size | DocType | Version | Access | License | ||
| Study on the hydroly（504KB） | 开放获取 | -- | View Download | |||
Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.
Edit Comment