| Summary: | 碩士 === 國立雲林科技大學 === 環境與安全工程系碩士班 === 90 === For activated sludge in the biodegradation reaction, electromagnetic effects has affected or not that have no any related literatures can be proved so far. In the magnetic field, organisms produce organism electromagnetic effects whether they can increase organism metabolism; in short, they can stimulate microorganisms that are biodegradable in contaminants to increase biological treatment efficiency. Hence, the research applies batch-activated sludge in the process of wastewater treatment that enwinds enameled insulated wire with AC & DC power supply. After the changes of current of voltage, it can provide different intensities of magnetic field in the artificial wastewater of biological treatment with additional magnetic filed stimulation in the reactor so that microorganism can have the effects of magnetic filed stimulation for a longer period of time. The research uses cooling bath effect in the reactor that applies inflow water approach to transmit thermal energy to the water and outflow to the reactor at the constant room temperature for the best growth environment.
From the research results, when intensities of DC magnetic field are 200G, COD removal rate has greater 5~12% than comparison group. Nevertheless, when intensities of DC magnetic field are 500G, COD removal rate has less 7~15% than comparison group. When intensities of AC magnetic field are greater than 200G, COD removal rate is 68% and less than 14% of comparison group. Furthermore, when intensities of DC magnetic field are 200G, rate constant is 0.26∼0.34 hr-1 in the reactor, then, biochemical rate constant is 0.158 L/(g-hr), growth constant is 0.47 (mg-MLSS/mg-COD), endogenous decay coefficient is 0.04 day-1, and specific oxygen uptake rate (SOUR) is 168.6 (mg-O2/g.hr); in the contrast with comparison group, rate constant is 0.22∼0.29 hr-1 in the reactor, then, biochemical rate constant is 0.38 L/(g-hr), growth constant is 0.47 (mg-MLSS/mg-COD), endogenous decay coefficient is 0.09 day-1, and SOUR is 93.28 (mg-O2/g.hr). Hence the influence of biological aerobic treatment system of wastewater has positive effect. Nevertheless, when intensities of DC magnetic field are 500G, it has affected the influence of biological aerobic treatment system of wastewater from a summary of each experimental variables of evaluation that has negative effects. However, AC magnetic field has caused thermal effect that has produced from a conductor, center of the reactor, because it can’t separate microorganisms and the conductor that has caused negative effect. The AC current has frequency of 50/60 Hz. When intensities of magnetic field has increased, internal of the reactor immediately raising temperature phenomenon. However, intensities of AC magnetic field is greater than 200G, it can’t use cooling water to keep constant temperature (room temperature) due to lack of the related data for evaluation. Hence, AC magnetic field for biological aerobic treatment system of wastewater has no obviously standard evaluation. From magnetic force microscope for organism observation, when intensities of magnetic field within 200G, organism has no apparently changes as well as microorganism stage has kept normal activity and excellent food supply. Nevertheless, when intensities of magnetic field are greater than 400G, microorganisms begin showing atresia phenomenon as well as activities are reduced. When intensities of magnetic field are greater than 600G, microorganism cells produce restrictive phenomenon or even die out.
Effects of magnetic field stimulation on biological aerobic treatment system of wastewater can be derived from the related experimental analysis. However, there are no evidences to figure out how magnetic filed direct or indirect affects microorganism biodegradation in the organic substances of wastewater, but there is one conclusion that magnetic field for biological aerobic treatment system of wastewater has no immediately dangerous situation.
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