| Summary: | 碩士 === 國立宜蘭大學 === 環境工程學系碩士班 === 98 === Since it’s high color and organics characteristics of dyeing wastewater, it is difficult to treat. In the characteristics, the treatment efficiency by biological method is pretty low. By using chemical treatment, the high treatment cost becomes the hinder to be used. The physical adsorption method is the most popular treatment method for this kind of wastewater. After the adsorption treatment, the effluent wastewater can meet the regulation. However, the adsorbent is so expensive that need to seek economical and effective substitute material. Wheat residue is the final waste from distillation process of wheat in drinking or wining industry. Waste wheat residue can be made to the compost as a soil conditioner. Wheat residue contains high organics. Therefore, this study made use of wheat residue as a carbon material. It can be regarded as adsorbent used for sewage treatment process which can not only solve the problem of it’s disposal but also reduce pharmaceutical cost and improve economic efficiency.
In this study, the wheat residue was obtained from KING CAR GROUP (Yilan Yuanshan Plant). One-stage activation and two-stage activation, respectively, will be used to prepare the activated carbon to adsorption of methyl blue dye. The characteristics analysis of the wheat residue (surface characteristics and pore size) was studied. The adsorption properties are investigated by isotherm and kinetic adsorption experiments.
The best adsorption condition of solution pH is all 7.0 ± 0.1 for the two different preparation forms of the activated carbon. However, by two-stage activation preparation of activated carbon has the better adsorption capacity. In addition, through the isotherm experimental results, the calculated n value or the Freundlich model is 4.405 ~ 8.219, belong the advantageous adsorption. By thermodynamics computation known, activated carbon for methyl blue adsorption is physical adsorption (-34.646 ~ -27.298 kJ mole-1), and for the spontaneous endothermic reaction (△H° is 46.740 kJ mole-1).
A kinetic study, the adsorption rate constant was decreased with the concentration of methyl blue increase and temperature rise. The optimization adsorption model for the adsorption is the Pseudo second order adsorption model. Calculating the activation energy by the Arrhenius equation shows that the study is a physical adsorption (Ea is 32.709 kJ mol-1). This result is the same with the isothermal adsorption experimental.
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