The Adsorption Of Reactive Dyes In Printing And Dyeing Wastewater Based On Supramolecular Interaction Of Cucurbituril

In the process of industrial application and production of dyes, large amount of printing and dyeing wastewater was produced. There are some polycyclic aromatic hydrocarbon compounds which contains –NH2,-H2SO3 and-NO2 groups in printing and dyeing wasterwater. High salt, high alkali and complicate composition make the printing and dyeing wastewater to do a great damage to enviorment. In water, even dyes are in very low concentration, it can still change the color of water and decrease light transmittance of water. As a result, it will affect the survival of animal and plants in water and damage the stability of ecosystem.Due to unique structure and excellent coordination ability, cucurbiturils have been widely applied. The dyes containing aromatic ring and disazo groups can form inclusion complexes with cucurbiturils. As a high efficient adsorbent, cucurbiturils have been used to remove reactive dyes in effluent. In this thesis, the cucurbit[6]uril(CB[6]) and cucurbit[8]uril(CB[8]) were used to adsorb reactive blue 19 and reactive yellow X-RG dyes in water, and their adsorption behavious and inclusion mechanism were researched.As for reactive blue 19 dye, the optimal doseage of CB[6] is 60 mg and of CB[8] is 15 mg; the adsorption rate will be above 90% when adsorption equilibrium has reached. Neutral and alkaline environment is conducive to the adsoption, but high temperature is inconducive to the adsorption. Ca2 +, K +, Mg2 +, Na + ions in different concentration have significant influences on the adsorption. The maximum adsorption capacity of CB[8] is 0.709 g/g. The adsorption isotherms data obtained at different temperatures were fitted well to the Langmuir isotherm. Adsorption thermodynamic functions, such as △G, △H and △S were evaluated and revealed that adsorption onto CB[8] and CB[6] was a spontaneous and enthalpy-driven process. The kinetics of the adsorption process was determined to follow the pseudo second-order rate equation indicating the chemisorption dominates the adsorption process. FT-IR,TG and DFT calculations revealed that the formation of inclusion complex was the main driving force of adsorption.As for reactive yellow X-RG, the optimal doseage of CB[6] is 100 mg and of CB[8] is 20 mg. The removal rate of dyes will be above 90% when adsorption equilibrium has reached. Neutral and alkaline environment is also conducive to the adsoption, but high temperature is inconducive to the adsorption. Ca2 +, K +, Mg2 +, Na + ions in different concentration also have significant influences on the adsorption of X-RG. The maximum adsorption capacity of CB[8] is 2.4 g/g. The adsorption isotherms data obtained at different temperatures were fitted well to the Langmuir isotherm. Adsorption thermodynamic functions, such as △G, △H and △S were evaluated and revealed that adsorption onto CB[8] and CB[6] was a spontaneous and enthalpy-driven process. The kinetics of the adsorption process was determined to follow the pseudo second-order rate equation indicating the chemisorption dominates the adsorption process. FT-IR, TG and DFT calculations confirm the formation of inclusion complex.