| Summary: | 碩士 === 中原大學 === 生物醫學工程研究所 === 107 === In recent years, the possibility of a global food shortage will increase significantly likely as a result of the climate change, fast development of industrialization and urbanization. Since arable land is hard to increase, the way to address the food shortage is to increase crop yields and accelerated crop growth rates. For cultivation of fruits and vegetables, hydroponic cultivation has been widely used. However, hydroponics has no soil can be used as buffer. If contaminated by pathogenic fungi and bacteria, the flows of nutrient solution will cause death of plants in the hydroponic system. In order to reduce the contamination by pathogenic fungi and bacteria, it is necessary to sterilize the nutrient solution. The nutrient solution is usually treated with conventional sterilization technologies such as UV exposure, ozone processing and membrane filtration. These technologies have many drawbacks such as long processing time, high running costs and require regular replacement. So, plasma is a better way to solve these problems. Plasma is a promising candidate for solving these problems because plasma excitation can produce reactive oxygen species (ROS), which is the main factor for inactivation of bacterial. This study is to develop an atmospheric pressure low temperature plasma equipment for hydroponic cultivation. As of the result, the plasma system operating peak-to-peak voltage, current, frequency and power consumption is 12.6 kV, 70.6 mA, 1180 Hz and 1.32 W respectively. After 15 minutes plasma treatment, the sterilization efficiency of E. coli can reach more than 99 %. In the cultivation of Brassica rapa chinensis experiment indicated that the growth rate is improved drastically with the plasma treatment. In the 15 minutes plasma treatment group (3 times a day and every 8 hours once), the plant grew 22.4% higher and 56.29% heavier than the control group. Therefore, this study successfully developed a set of atmospheric pressure low temperature plasma equipment for hydroponic cultivation, which can improve the growth rate of Brassica rapa chinensis and solve the water pollution problem.
|
|---|
