The fates of microcystins in natural soil/water system

• Main Authors: Ya-lan Hu, 胡雅嵐
• Other Authors: Jiunn-fwu Lee
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/05215320340413954500

碩士 === 國立中央大學 === 環境工程研究所 === 97 === Microcystin is a common toxin in the eutrophic lakes and reservoirs. However, the mechanism of the transportation of microcystin in lakes and reservoirs, especially, in micro-environment of the soil/water system is not yet clarified. The adsorption and photodegradation of microcystin poisoning could adversely affect the environment. Hence, the main purpose of this study was focused on the major factors that affect the transportation and fate of microcystin in natural water. The adsorption behaviour of microcystin was examined by collecting the soil/water samples from river or reservoir. The photodegradation of microcystin was studied by irradiating with different wavelengths of UV light. The adsorption and photodegradation of microcystin were examined by HPLC/UV techniques. The results of this study conveyed that the reservoir or river sediment, suspended solid and humic acid solution had an impact on the adsorption of microcystin and thereby affected the transportation and fate of microcystin. The adsorption of microcystin was found to be proportional to the distribution and composition of organic matter contents. When the soil/water systems contain more humic acid, the system of microcystin adsorption would increase and the larger content of humic acid solution resulted into greater poisoning of environment by microcystin adsorption. Analysis on the microcystin poisoning at the surface of sediment particles was also carried out. The results revealed that the larger adsorption of microcystin would lower the pH value of the system. The combination of both organic matter and sediment would necessarily enhance the adsorption of microcystin on the environment. The observation on photodegradation of microcystin explained that the generation of toxic microcystis pigments also affected the environment to a greater extent and poisoned the water system by releasing the coloring agents. Despite, the photodegradation was affected to some extent by suspended particles or humic acid in water, the irradiation of light had significant effect on this. Therefore, the adsorption and photodegradation of microcystin were clearly analyzed in this research for the better understanding of water pollution in the environment.