1990 Fiscal Year Final Research Report Summary
High Rate Water and Wastewater Treatment by Fluidized Pellet Bed Separator
| Project/Area Number |
63460167
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
都市工学・衛生工学
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| Research Institution | Hokkaido University |
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Principal Investigator |
TAMBO Norihito Hokkaido Univ. Faculty of Eng. Professor, 工学部, 教授 (80001147)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUI Yoshihiko Hokkaido Univ. Faculty of Eng. Assistant, 工学部, 助手 (00173790)
SHIMIZU Tatsuo Hokkaido Univ. Faculty of Eng. Assist. Professor, 工学部, 助教授 (10029291)
KAMEI Tasuku Hokkaido Univ. Faculty of Eng. Assist. Professor, 工学部, 助教授 (70001998)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Pellet separation / Turbidity removal / Color removal / High rate water treatment / High rate sewage treatment / Pellet flocculation / Fluidized bed separation |
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| Research Abstract |
The results obtained can be summarized as follows.
(1) Clay suspension (turbidity) removal : A Proper usage of chemicals in combination of cationic metal coagulant (Aluminium) with weakly anionic or nonionic polymer flocculant was studied. An optimal ALT-ratio is determined at the level of Z.P = - 213EA\ : 0mV.The corresponding PT-ratio is determined on the ratio of PT/ALT = 0.5.
(2) Clay suspension and color colloid removal : At the ratio of (color unit)/(Turbidity) = 1.0 or less a good pellet flocculation in the fluidized bed separator is obtainable. To carry out a good fluidized bed operation. raw water turbidity should b13EA\ : e greater than 200 unit in order to generate a good pellet. The dosage of coagulants and optimal pH is the same to those for color floc formation. i.e. the critical Z.P.= - 10-13 mV and optimal pH = 5.5. the ratio PT/ALT required is about 0.5.
(3) Instead of the primary sedimentation basin in a conventional biological treatment systems a fluidized pellet bed separator is introduced with dosages of aluminium and polymer coagulants. With a high separation rate as LV = 100-200/d an ample rem13EA\ : oval of suspended matters and higher molecular weight organic substances was obtained. The effluent from the fluidized pellet contains only lower molecular weight organics. Hence, simple aerobic biological filter with short detention time as short a13EA\ : s 1-2 hr can eliminate BOD to a level of 5-10 mg/L.With fluidized pellet bed operation. phosphate is also reduced to a level of 0.1 mg/L.
(4) Advanced sewage treatment system which can perform removal of BOD, phosphate and nitrogen in a united process is also examined with the use of the fluidized pellet bed separator.
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