Development of multifunctional biochar bead carriers for application in bioremediation of contaminated groundwater

• Main Authors: Wei-cheng Li, 李偉誠
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/42231028966151355902

碩士 === 國立雲林科技大學 === 環境與安全衛生工程系碩士班 === 101 === First of all, this study is using the common plant fiber (e.g. bamboo and rice husk) to produce bio-char through the pyrolysis process and employing the isothermal adsorption models (such as Freundlich and Langmuir) to explore what kind of the bio-char produced in a specific temperature may have the optimal effect to adsorb organic compounds, and so we may use it as a main source of the follow-up biochar. Secondarily, we use the response surface methodology (RSM) to develop the multifunctional biochar-bead-carrier with the best oxygen-releasing effect in a long-term base, and to analyze characteristics of the developed carrier. Finally, we apply the multifunctional biochar-bead-carrier onto the system of permeable reactive barrier (PRB) to evaluate the carrier’s capability of remediating the groundwater contaminated by BTEX. Moreover, we also use the scanning electron microscope (SEM) to analyze the biochar, micro capsule, and multifunctional biochar-bead carrier before and after our experiment. The research findings show, (1). According to the biochar made of different biochar materials and pyrolysis temperatures, the bamboo char and the rice-husk char baked at 350 oC and 750 oC both are having a good adsorbing capability on BTEX; (2) By simulated result of the isotherm adsorption model, we have learnt that Freundlich model is comparatively consistent with our research findings; adsorption of the bamboo char baked at 350 oC is much better than that of the rice-husk char baked at 750 oC; (3) The best ratio constituting the multifunctional biochar-bead-carrier developed by RSM are respectively as concentration of the PVA weight percentage is 10.34%, and the biochar weight is 13.23 g, which can be produced as an uneasy disintegrating carrier with the best oxygen-releasing effect and excellent structure. Furthermore, the internal microbe observed by SEM still maintains its activity that can be applied to the flowing groundwater; (4) Applying onto PRB system with and/or without mixed bacteria, the multifunctional biochar-bead-carrier has distinct restoring effect in the experiment proceeded within the groundwater contaminated by BTEX at concentration of 120 mg/L; it shows, the carrier in PRB System can effectively provide oxygen and microbes and adsorb BTEX. In addition, in compliance with contaminants’ categories of the groundwater, we may decide what kind of the decomposing bacteria we shall embed it to restore the groundwater contaminated by specific pollutants; (5) We learned from the SEM analysis, the multifunctional biochar-bead-carrier has many apertures which are not only adsorbing organic pollutants, but also providing a good growing space for microbes.