1996 Fiscal Year Final Research Report Summary
An Investigation on Water Quality Control with Functional Gels
| Project/Area Number |
06452441
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
環境保全
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KUSUDA Tetsuya Kyushu Univ., Dept.of Civil Eng, Professor, 工学部, 教授 (50037967)
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| Co-Investigator(Kenkyū-buntansha) |
OISHI Kyoko Kyushu Univ., Dept.of Civil Eng., Research Associate, 工学部, 助手 (20110835)
MORIYAMA Katsumi Kyoritsu Univ., Dept.of Civil Eng., Associate Professor, 工学部, 助教授 (80157932)
IRIE Masahiro Kyushu Univ., Dept.of Applied Chemical Eng., Professor, 工学部, 教授 (30001986)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Intelligent material / Water quality / Water and waste water treatment / Gel / Actuator / pH / NIPAAm gel |
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| Research Abstract |
(1) Application of Functional Gels to Increase in Rate of Biological Nitrification
A method to increase the nitrification rate with an advantage of the immobilization technique was developed. N-isopropylacrylamide (NIPAAm) was adopted as a functional gel which shrinks and swells reversibly depending on the change of temperature, e.g., a thermo-responsive gel. Effects of the volume phase transition of the gel on the nitrification activity were studied. Nitrifiers were immobilized in the gel, and pellets of it were incubated under a cyclic thermal operation between 25 and 35 ﾟC.It was compared with the nitrification activity by nitrifiers immobilized in the gel under three isothermal operations at 25,28 and 35ﾟC.In conclusion, the nitrification activity is enhanced by utilization of the thermo-responsive gel. Under the cyclic thermal operation, a drastic increase in the rate of nitrification occurs due to a "pumping effect" caused by the volume phase transition of the thermo-responsive ge
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(2) Kinetic Studies on Volume Phase Transition Processes of Electro-Responsive Functional Gels
Electro-responsive functional gels synthesized by 2-acrylamide-2-methylpropane sulfonic acid (PAMPS) or methacrylic acid (PMAA), were examined on bending characteristics under an electric field. The bending speed was proportional to the field strength. Both gels responded quite rapidly to electro-stimuli, in comparison with thermo- and pH-responsive functional gels. Bending of the gels took place toward the negative electrode within several seconds to minutes. Further studies should aim at utilization of the electro-responsive gels not only as an actuator, i.e., a chemical valve, in water treatment systems, but also as an immobiklzation medium for microorganisms in waste water treatment systems.
(3) Development and Control of a Chemical Valve
pH-responsive functional gels were synthesized by NIPAAm with methacrylic acid, in order to examine swelling characteristics of the gels and to develop a chemical valve which can control a flow rate of air in an aeration tank. The proposed chemical valve could control the flow rate of air in distillled water. However in sewage the pH-responsive functional gels swelled and shrank slightly with large pH-stimuli. Therefore it was difficult to control the flow rate of air by the chemical valve in a solvent with high ionic strength like sewage. This indicates that new pH-responsive functional gels should be synthesized, otherwise new types of chemical valves should be proposed. Less
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