Biological Emulsification and Decomposition of Total petroleum Hydrocarbons in the Soil

• Main Authors: Hung-Yi Li, 李泓毅
• Other Authors: Jiunn-Jyi Lay
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/29688757869128654595

碩士 === 國立高雄第一科技大學 === 環境與安全衛生工程研究所 === 102 === Previous study concluded that the period of plant seed germination could obviously stimulate the Bacillus sp.- rich broth decomposing diesel. That fact was because that the period had amount of amylase releasing from the seed. Some studies indicate that the Bacillus sp. can produce some biosurfactant while they use the carbohydrates. This study tried to understand the diesel decomposing mechanisms whether processing a further emulsification for the bacterial decomposition or not. For this purpose, some experimental works were performed including （i）amylase quantity, （ii）Bacillus sp.- rich broth emulsifying diesel monitor, （iii）Bacillus sp.- rich broth decomposing diesel detection, and （iv）bacterial population observations. Multivariable analysis for amylase quantity indicated that an optimal amylase concentration and time were occurred at 428 ppm and 39 minutes, respectively. Based on this, the amylase concentration of seed germination used in this study was approximately 289 ppm. Under this condition and a 4 - week observation, 76% and 32% of diesel decomposing ratios were harvested from microbial and plant（seed） amylase with Bacillus sp.- rich broth, respectively. Additionally, the increase of microbial amylase concentration could decrease and increase surface tension and hydrophilicity, respectively. In this study, we found that 45% diesel would be emulsified with an amylase concentration of 285 - 400 ppm. Their surface tensions were located at 51.3 - 46.97 mN/m. Finally, the bacterial growth was corresponding to the diesel decomposition. A high number of 1.1×1010 CFU/g dry soil found at this study was obvious that the Bacillus sp.- rich broth could effectively emulsify and decompose diesel while the amylase participation.