title: Effect of shear force and solution pH on flocs breakage and re-growth formed by nano-Al(13) polymer.
abstract: The breakage and re-growth of flocs formed by polyaluminum chloride (PAC) and the Al(13)O(4) (OH)(24)(7+) (Al(13) for short) polymer were comparatively evaluated for the coagulation of humic acid (HA). A series of jar experiments were conducted to investigate the impacts of shear rate and solution pH on flocs breakage and re-aggregation potential. Results indicated that the responses of flocs to the increasing shear force and solution pH depend on the coagulant used. The ability of flocs to resist breakage decreased with the increasing shear rate. For all levels of shear force investigated in this study, the flocs formed by Al(13) polymer were weaker than those of PAC, whereas Al(13) polymer displayed a better recoverability than PAC. The similar results were obtained when pH of solution was changed. The flocs generated in acidic conditions were stronger and more recoverable than those generated in alkaline conditions no matter which coagulant was used.
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, 250100 Jinan, China. yingying3227@mail.sdu.edu.cn
authors.forename: Weiying
authors.initials: W
authors.lastname: Xu
authors.forename: Baoyu
authors.initials: B
authors.lastname: Gao
authors.forename: Qinyan
authors.initials: Q
authors.lastname: Yue
authors.forename: Yan
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000143:Acids / Q000737:chemistry; D000468:Alkalies / Q000737:chemistry; D000536:Aluminum Hydroxide / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry*; D005427:Flocculation; D006812:Humic Substances / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D012996:Solutions; D013314:Stress, Mechanical; D013997:Time Factors
chemical_list: D000143:Acids; D000468:Alkalies; D006812:Humic Substances; D011108:Polymers; D012996:Solutions; C016213:aluminum oxychloride; D000536:Aluminum Hydroxide; D000537:Aluminum Oxide