| Summary: | 碩士 === 國立臺灣大學 === 環境工程學研究所 === 96 === The study focused on the adsorption mechanism of 4-nonylphenol in water with carbon nanotubes. The primary sources of nonylphenol are surfactant, emulsifying agent, and additive of plastic product, etc. Nonylophenol which belongs to endocrine disrupting compounds (EDCs) has many characteristics such as low solubility, persistent and difficulty to be decomposed by biodegradation. Therefore, it might cause the toxicity in ecosystems and aquatic organisms. 4-Nonylphenol could not be removed completely via traditional wastewater treatment processes, but it could be discharged directly into aquatic environments. In this study, the adsorption efficiency for nonylphenol from water samples was estimated by four adsorbents, including powder activated carbon (PAC), single-wall carbon nanotubs (SWCNT), mult-wall carbon nanotubs (MWCNT), and bundle carbon nanotubs (BCNT).
The effect of the parameters, such as specific surface area and pore size of adsorbent as well as properties of adsorbate on adsorption capacity were studied. 4-nonylphenol which was adsorbed in smaller porous adsorbate was hard to be washed out during constant-temperature vibrating process. In kinetic adsorption experiments, the highest saturated adsorption rate of the four adsorbents is 70~80 %. The adsorptions behavior of 4-nonylphenol onto PAC, SWCNT, MWCNT and BCNT coincided with the pseudo second-order model (R2= 0.95). In this study the Langmuir, Freundlich and BET isotherms were simulated. The adsorption isotherms of 4-nonylphenol of the selected adsorbates fitted the Freundlich isotherm fairly well. From Freundlich isotherm model, MWCNT had the highest adsorption capacity among the selected adsorbates in the higher equilibrium concentration. In constant PAC and MWCNT had higher adsorption capacity in the lower equilibrium concentration.
|
|---|
