| Several different adsorbents by modifying cellulose have been designed and synthesized on thebasis of some relevant references. Those adsorbents have been characterized by FTIR, SEM, TGA andelementary analysis. Batch experimental procedures were conducted to investigate the adsorption ability ofthe adsorbent to adsorb heavy metal ions and organic dyes from the aqueous solution. The influence ofdifferent experimental parameters such as pH, shaking time, amount dosage, initial concentration andtemperature on removal process was evaluated, as well as the adsorption isotherms and kinetic study. Theresearch contents were as follow:1. Based on the researches of modified cellulose both at home and abroad, the methods ofmodified cellulose, including directly modified cellulose and indirectly modified cellulose, was expoundconcretely. Besides, the problems at the present stage and development trends in the future of thecellulose-based water treatment agent have been analyzed too. The basis of subject selection and the majorwork of this thesis were depicted in detail.2. The CM adsorbent, which was synthesized by modified cellulose with maleic anhydride, wasused to uptake heavy metal ions （Hg （Ⅱ）） and organic dyes （basic fuchsine, methylene blue and crystalviolet） from the aqueous solution. The experiment results show that the optimum adsorption pH of Hg （Ⅱ）,basic fuchsine, methylene blue and crystal violet is5.1,6.5,8.0and6.3, respectively; the optimumadsorption temperature of Hg （Ⅱ）, basic fuchsine, methylene blue and crystal violet is30℃,25℃,25℃and25℃, respectively; the optimum adsorption time of Hg （Ⅱ）, basic fuchsine, methylene blue and crystalviolet is60min,120min,60min and180min. The adsorption process of Hg （Ⅱ） was described byFreundlich isotherm model and pseudo-second-order kinetic isotherm, while that of three kinds of organicdyes was depicted by the Langmuir isotherm model and pseudo-second-order kinetic isotherm.3. The CMT adsorbent, which was further modified CM with thiourea, was used to treat with Cd（Ⅱ） ions and basic fuchsine. The optimum adsorption condition of Cd （Ⅱ） is pH4.8, amount dosage60mgand contact time40min, while that of basic fuchsine is pH7.0, amount dosage70mg, contact time150min and temperature30℃. The adsorption process of Cd （Ⅱ） and basic fuchsine on CMT adsorbent fit the assumptions of Langmuir isotherm and pseudo-second-order kinetics model, and the maximum adsorptioncapacity of Cd （Ⅱ） and basic fuchsine is94.97mg g-1and26.47mg g-1, respectively. Besides, theexperiment results of adsorption/desorption of Cd （Ⅱ） show that the CMT adsorbent could be reused6times at least with the0.20mol L-1NaOH solution as a desorption agent.4. The maleic anhydride epoxy cellulose （CMG）, which was designed and synthesized bymodifying CM with glycidylmethacrylate （GMA）, was further modified with thiourea to built a noveladsorbent （CMGT） with two kinds of functional groups. The CMGT adsorbent was used to uptake Pb （Ⅱ）and malachite green from aqueous solution. Batch experimental procedures were conducted to investigatethe adsorption ability of the CMGT adsorbent to adsorb Pb （Ⅱ） ions and malachite green from the aqueoussolution. The experiment results show that, the optimum adsorption condition of Pb （Ⅱ） is pH5.5, shakingtime60min, temperature30℃and initial concentration0.08mol L-1, while that of malachite green is pH7.0, shaking time180min, temperature40℃and initial concentration150mg g-1. The adsorption processof Pb （Ⅱ） and malachite on CMGT adsorbent is described by the Langmuir isotherm model andpseudo-second-order kinetic model correctly, and the maximum adsorption capacity of Pb （Ⅱ） andmalachite green on CMGT adsorbent is584.80mg g-1and131.93mg g-1, respectively. The experimentresults of adsorption/desorption of Pb （Ⅱ） show that the adsorption capacity of Pb （Ⅱ） on CMGT adsorbentis still over400mg g-1after reused6times, indicated that the CMGT adsorbent is with a excellentregenerated and reused ability and will be used in many fields. |
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