References

1. N. Shirasaki, T. Matsushita, Y. Matsui, A. Oshiba, T. Marubayashi, S. Sato, Improved virus removal by high-basicity polyaluminum coagulants compared to commercially available aluminum-based coagulants, Water Res., 48 (2014) 375–386.
2. I. Zarchi, E. Friedler, M. Rebhun, Polyaluminium chloride as an alternative to alum for the direct filtration of drinking water, Environ. Tech., 34 (2013) 1199–1209.
3. J. Mertens, B. Casentini, A. Masion, R. Pȍthig, B. Wehrli, G. Furrer, Polyaluminum chloride with high Al30 content as removal agent for arsenic-contaminated well water, Water Res., 46 (2012) 53–62.
4. W.H. Casey, Large aqueous aluminum hydroxide molecules, Chem. Rev., 106 (2006) 1–16.
5. H.X. Tang, Theory of Inorganic Polymer Flocculation and Flocculants, China Architecture Press, Beijing, China, 2006.
6. J.M. Duan, J. Gregory, Coagulation by hydrolysing metal salts, Adv. Colloid Interface Sci., 100–102 (2003) 475–502.
7. V. Kazpard, B.S. Lartiges, C. Frochot, J.B. d’Espinose de la Caillerie, M.L. Viriot, J.M. Portal, T. Gorner, J.L. Bersillon, Fate of coagulant species and conformational effects during the aggregation of a model of a humic substance with Al13 polycations, Water Res., 40 (2006) 1965–1974.
8. T. Takaara, D. Sano, H. Konno, T. Omura, Cellular proteins of Microcystis aeruginosa inhibiting coagulation with polyaluminum chloride, Water Res., 41 (2007) 1653–1658.
9. A.I. Zouboulis, N. Tzoupanos, Alternative cost-effective preparation method of polyaluminium chloride (PAC) coagulant agent: Characterization and comparative application for water/wastewater treatment, Desalination, 250 (2010) 339–344.
10. M.Q. Yan, D.S. Wang, J.H. Qu, W.J. He, C.W.K. Chow, Relative importance of hydrolyzed Al(III) species (Ala, Alb, and Alc) during coagulation with polyaluminum chloride: a case study with the typical micro-polluted source waters, J. Colloid Interf. Sci., 316 (2007) 482–489.
11. C.Q. Ye, Z. Bi, D.S. Wang, Formation of Al30 from aqueous polyaluminum chloride under high temperature: Role of Al13 aggregates, Colloid Surf., A436 (2013) 782–786.
12. S.L. Wang, M.K. Wang, Y.M. Tzou, Effect of temperatures on formation and transformation of hydrolytic aluminum in aqueous solutions, Colloid Surf. A, 231 (2003) 143–157.
13. G. Furrer, B.L. Phillips, K.-U. Ulrich, R. Pöthig, W.H. Casey, The origin of aluminum flocs in polluted streams, Science, 297 (2002) 2245–2247.
14. L. Allouche, F. Taulelle, Conversion of Al13 Keggin ε into Al30: are action controlled by aluminum monomers, Inorg. Chem. Commun., 6 (2003) 1167–1170.
15. P.H. Hsu, D. Cao, Effects of acidity and hydroxylamine on the determination of aluminum with ferron, Soil Sci., 152 (1991) 210–219.
16. C.H. Feng, B.Y. Shi, D.S. Wang, G.H. Li, H.X. Tang, Characteristics of simplified ferron colorimetric solution and its application in hydroxy-aluminum speciation, Colloid Surf. A, 287 (2006) 203–211.
17. C.Q. Ye, D.S. Wang, X.H. Wu, J.H. Qu, k-Value-based ferron assay and its application, J. Colloid Interface Sci., 335 (2009) 44–49.
18. W.Z. Zhou, B.Y. Gao, Q.Y. Yue, L.L. Liu, Y. Wang, Al-Ferron kinetics and quantitative calculation of Al(III) species in polyaluminum chloride coagulants, Colloid Surf. A, 278 (2006) 235–240.
19. P.M. Bertsch, W.J. Layton, R.I. Barnhisel, Speciation of hydroxyl-aluminum solutions by wet chemical and aluminum-27 NMR methods, Soil Sci. Soc. Am. J., 50 (1986) 1449–1454.
20. P.M. Bertsch, R.I. Barnhisel, G.W. Thomas, W.J. Layton, S.L. Smith, Quantitative determination of aluminum-27 by hig–resolution nuclear magnetic resonance spectrometry, Anal. Chem., 58 (1986) 2583–2585.
21. D.Z. Denney, P.H. Hsu, Aluminum-27 nuclear magnetic resonance and ferron kinetic studies of partially neutralized aluminum chloride solutions, Clay Miner., 34 (1986) 604–607.
22. C.H. Feng, H.X. Tang, D.S. Wang, Differentiation of hydroxyl-aluminum species at lower OH/Al ratios by combination of 27Al NMR and Ferron assay improved with kinetic resolution, Colloid Surf. A, 305 (2007) 76–82.
23. D.R. Parker, P.M. Bertsch, Identification and quantification of the “Al13” tridecameric polycation using ferron, Environ. Sci. Technol., 26 (1992) 908–914.
24. J. Zhang, F. Chang, Y.J. Ren, Q.Y. Shi,An important improvement in ferron-timed spectrophotometry, Applied spec., 67 (2013) 985–992.
25. Y.B. Chu, B.Y. Gao, Q.Y. Yue, Y. Wang, S.G. Wang, Characterization and separation of Al13 species using gel-filtration chromatography, Sci. China Ser., B49 (2006) 326–331.
26. D.S. Wang, H.X. Tang, J. Gregory, Relative importance of charge neutralization and precipitation on coagulation of kaolin with PACl: effect of sulfate ion, Environ. Sci. Technol., 36 (2002) 1815–1820.
27. P.P. Tsai, P.H. Hsu, Studies of aged hydroxide-aluminum solutions using kinetics of aluminum- Ferron reactions and sulfate precipitation, Soil Sci. Soc. Am. J., 48 (1984) 59–65.
28. J. Zhang, X.J. Yong, D.Y. Zhao, Q.Y. Shi, Accurate quantification of two key time points used in the determination of hydroxyl polyaluminum species by Ferron timed spectrophotometry, J. AOAC Int., 98 (2015) 225–229.
29. J.W. Akitt, Multinuclear studies of aluminum compounds, Prog. Nucl. Mag. Res. Sp., 21 (1989) 1–149.
30. Z.Y. Chen, Z.K. Luan, B. Fan, Z.G. Zhang, Y.Z. Li, Z.P. Jia, Quantitative studies on keggin polycation Al13 and Al30 in hydrolytic polymeric aluminum aqueous solution by 27Al nuclear magnetic resonance, Chinese J. Anal. Chem., 34 (2006) 38–42.
31. G. Smith, U.D. Wermuth, P.C. Healy, Proton-transfer compounds of 8-hydroxy-7-iodoquinoline-5-sulfonic acid (Ferron) with 4-chloroaniline and 4-bromoaniline, Acta Cryst., C63 (2007) o405–o407.
32. Y.B. Chu, B.Y. Gao, Q.Y. Yue, Y. Wang, S.G. Wang, Electrical charges and coagulation efficiency of Al13 species in polyaluminum chloride (PAC), Environ. Chem. (in Chinese), 26 (2005) 119–122.
33. B.Y. Shi, G.H. Li, D.S. Wang, H.X. Tang, Separation of Al13 from polyaluminum chloride by sulfate precipitation and nitrate metathesis, Sep. Purif. Technol., 54 (2007) 88–95.
34. B.Y. Gao, Q.Y. Yue, Y. Wang, H. Yu, Study on the aluminum species of PACS by using Al-Ferron timed complex colorimetric method, Environ. Chem. (in Chinese), 15 (1996) 234–239.
35. L. Feng, Z.K. Luan, H.X. Tang, The study on speciation analysis methods for hydrolysis polymerization of aluminum, Environ. Chem., 12 (1993) 373–379.
36. D.S. Wang, W. Sun, Y. Xu, H.X. Tang, J. Gregory, Speciation stability of inorganic polymer flocculant-PACl, Colloid Surf. A, 243 (2004) 1–10.
37. J.Y. Bottero, M. Axelos, D. Tchoubar, J.M. Cases, J.J. Fripiat, F. Fiessinger, Mechanism of formation of aluminum trihydroxide from Keggin Al13 polymers, J. Colloid Interf. Sci., 117 (1987) 47–57.
38. J.Y. Bottero, D. Tchoubar, M.A.V. Axelos, P. Quienne, F. Fiessinger, Flocculation of silica colloids with hydroxy aluminum polycations. Relation between floc structure and aggregation mechanisms, Langmuir, 6 (1990) 596–602.
39. J.C. Goodwin, S.J. Teat, S.L. Heath, Gallium, clusters: How do clusters grow? The synthesis and structure of polynuclear hydroxide gallium(III) clusters, Angew. Chem. Int. Ed., 43 (2004) 4037–4041.
40. X.F. Jia, D.W. Fan, P.Q. Tang, J.C. Hao, L.Y. Ma, T.B. Liu,“Second organized structures” of nanoscale inorganic polyoxomolybdate compounds, Acta Phys.-Chim. Sin. (in Chinese), 22 (2006) 1300–1304.
41. T.B. Liu, E. Diemann, H.L. Li, A.W.M. Dress, A. Muller, Self-assembly in aqueous solution of wheel-shaped Mo154 oxide clusters into vesicles, Nature, 426 (2003) 59–62.