An Investigation on Water Quality Control with Functional Gels

(1)功能凝胶在提高生物硝化速率中的应用研究了一种利用固定化技术的优势提高生物硝化速率的方法。采用n -异丙基丙烯酰胺（NIPAAm）作为一种随温度变化可逆收缩和膨胀的功能凝胶，即热敏凝胶。研究了凝胶的体积相变对硝化活性的影响。将硝化物固定在凝胶中，将其颗粒在25 ~ 35ºC的循环热操作下孵育。在25、28、35℃的等温条件下，比较了固定在凝胶中的硝化菌的硝化活性。综上所述，热敏凝胶的使用提高了硝化活性。(2)电响应功能凝胶的体积相变动力学研究2-丙烯酰胺-2-甲基丙烷磺酸（PAMPS）或甲基丙烯酸（PMAA）合成的电响应功能凝胶在电场作用下的弯曲特性进行了研究。弯曲速度与场强成正比。与热响应和ph响应功能凝胶相比，这两种凝胶对电刺激的反应都相当快。在几秒钟到几分钟内，凝胶向负极弯曲。进一步的研究应着眼于利用电反应凝胶不仅作为水处理系统中的执行器，即化学阀，而且作为废水处理系统中微生物的固定化介质。(3)化学阀的研制与控制采用NIPAAm与甲基丙烯酸合成ph响应功能凝胶，研究凝胶的溶胀特性，并研制一种控制曝气池空气流速的化学阀。所提出的化学阀可以控制蒸馏水中空气的流速。而在污水中，ph响应功能凝胶在较大的ph刺激下会轻微膨胀和收缩。因此，在污水等高离子强度的溶剂中，用化学阀控制空气流量是困难的。这表明应该合成新的ph响应功能凝胶，否则应该提出新型的化学阀。少

(1) Application of Functional Gels to Increase in Rate of Biological NitrificationA 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 … More l.(2) Kinetic Studies on Volume Phase Transition Processes of Electro-Responsive Functional GelsElectro-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 ValvepH-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