| The third generation cellulose-based water treatment agent is a new-style cellulose derivative macromolecule functional material. In the first place, the issue was carried out exploratory research on thiomalic acid-type epoxy cellulose-based water treatment agent, which obtained from Chelest Company in Japan, was adsorbed copper ions in aqueous solution. And then, synthesis on new-style adsorbent was based on characteristics of adsorbent structure and combined with relevant information at home and abroad using changed the functional group method. Third generation cationic-modifiedβ-cyclodextrin-type, D-glucose-type, and cationic-modified D-glucose compound type cellulose-based epoxy water treatment agent were prepared, respectively. The appearance, composition and content, structure, thermal stability, and other aspects of sample was characterized and confirmed by a series of analytical method. Using batch adsorption and column adsorption, the best conditions of cellulose-based water treatment agent adsorption/desorption and application were determined. The adsorption kinetics, isotherm model, and thermodynamics of cellulose-based water treatment agent have been studied. The research topics described as following:1) Cellulose–based water treatment agent was classified and divided according to the structure characteristics of it in this paper. The recent progress was reviewed in five respects: carrier form, grafted method for grafting chain and carrier, selected for adsorption/desorption functional group and technique of functionalization, influencing factors in the performance of adsorption/desorption, and desorption method. The future direction of development was prospected. The context, significance, purpose and content of subject was described in detail.2) Thiomalic acid-type epoxy cellulose-based water treatment agent has been studied for the adsorption of copper ions in aqueous solution. The experiment data suggest that: the best acidity range of pH3-6, and the best experimental acidity of pH5.0 was selected; 90min was recognized as the optimum adsorption time; The kinetics of the adsorption process indicated that pseudo-second-order kinetics best described the overall process, and the initial sorption rate can be up to 0.2245mg g-1 min-1; The adsorption process was best described by the Langmuir model of adsorption, and the maximum adsorption capacity of Cu2+ was calculated as 15.10mg/g; when the solution was detailed and contained to copper ions, the treatment result by adsorbent does accord with the standard for drinking water(1mg/L).3) Third generation cationic-modifiedβ-cyclodextrin-type, D-glucose-type, and cationic-modified D-glucose compound type cellulose-based epoxy water treatment agent were prepared by using cellulose as raw material, respectively. Samples were confirmed by scanning electron microscopy, elemental analysis, fourier transform infrared spectroscopy analysis, thermogravimetric analysis and differential thermal analysis.4) From cationic-modifiedβ-cyclodextrin-type cellulose-based water treatment agent on the adsorption on phenolphthalein experiment can be seen that: selected optimum adsorption time was up to 180min; The kinetics of the adsorption process in line with pseudo-second-order kinetics, and the initial sorption rate should be up to 1408mg g-1 min-1; The best experimental pH12.0 was selected from the optimum pH range of 9 to 13; The adsorption process was best described by the Langmuir model of adsorption, and the maximum adsorption capacity of phenolphthalein was calculated as 258.4mg/g; the adsorption thermodynamics studies has shown that the adsorption is anothermic.5) The cationic-modifiedβ-cyclodextrin-type double functional cellulose-based water treatment agent was adsorbed Cr (VI) in aqueous solution. Based on the adsorption tests data: the appropriate acidity range of adsorption is pH4~6, from which pH4.5 was selected; The adsorption amounted up to 98.5% when shaking for 10 minutes, and a choice of 90 minutes as the best adsorption time; The kinetics of the adsorption process is fitted in with pseudo-second-order kinetics, and the initial sorption rate should be up to 751.88mg g-1 min-1; the optimum adsorbent dose was 50mg, while percentage removal of Cr(VI) was 99.5%; when the percentage absorption was kept at the rate of 95%, only 50mg/L Mn2+ was interfered; The adsorption process was best described by the Langmuir model of adsorption, and the maximum adsorption capacity of Cr(VI) was determined to 61.05mg/g; 0.50 mol L-1 NaOH as a desorption agent has chosen; after adsorbent was regenerated and reused 5 times in the adsorption and desorption of Cr(VI), the adsorption/desorption rate without obvious loss; When the solution contains only 50 mg/L and 5 mg/L Cr(VI), the adsorption data meet the requirements of the standard for integrated wastewater discharge GB8978-1996 (0.5mg/L) drinking water quality and the standard for drinking water(0.05mg/L), respectively.6) D-glucose-type cellulose-based water treatment agent was adsorbed on Cr(VI) in aqueous solution. It can be found that: The best acidity range of pH3~6, and selection of the best acidity is pH4.0; The adsorption amounted up to 97% when shaking for 10 minutes, and the adsorption time was made choice of 90 minutes; The kinetics of the adsorption process is fitted in with pseudo-second-order kinetics, and the initial sorption rate was 138.10mg g-1 min-1;According to the standard for integrated wastewater discharge GB8978-1996(0.5mg/L) and the adsorption rate was up to 99.3%, optimum adsorbent dosage is selected 50mg; The adsorption process was best described by the Langmuir model of adsorption, and the maximum adsorption capacity of Cr(VI) was 54.59mg/g; when the absorption rate remained 95% at least for test, only 50mg/L Mn2+ will be affected; the optimal concentration of NaOH solution, as a desorption agent, was opted for 0.05mg/L; when adsorbent was reused for six times, the adsorption/desorption rate haven't changed; When it contains only 5 mg/L Cr(VI) in the solution, the adsorption data can be reached the requirement of the standard for drinking water(0.05mg/L).7) Cationic-modified D-glucose compound type cellulose-based water treatment agent for effective separation of Cr(VI) from aqueous solution. Conclusion of experiment is that: experimental selection of the best acidity is pH3.5, which was due to the best pH range from 2.5 to 6.5; The adsorption amounted up to 97.6% when shaking for 10 minutes, and the best adsorption time 90 minutes was determined for the future test; The kinetics of the adsorption process is fitted in with pseudo-second-order kinetics, and the initial sorption rate was 165.84mg g-1 min-1; Based on the Integrated Wastewater Discharge Standard GB8978-1996(0.5mg/L) and adsorption rate can be up to 99.3%, 50mg as a optimum adsorbent dose was chosen; The adsorption process was best described by the Langmuir model of adsorption, and the maximum adsorption capacity of Cr(VI) was 71.79mg/g; if the adsorption rate was maintained 95%, the result for interference test were satisfactory; the desorption rate was up to 99.7% using 0.05mg/L NaOH solution as a desorption agent; desorption was repeated at least six times, and the adsorption/desorption rate without any obvious change; the concentration of Cr(VI) was reduced 0.033mg/L in the filtrate when there is only 5mg/L Cr(VI) contained in the solution. The result can be achieved the requirement of drinking water quality standard (0.05mg/L).According to the advantage of three new-styles cellulose-based water treatment agents, such as non-toxic, non-polluting, low cost, widely used, rapid absorption, stable adsorption, reusable, etc., it will have a good development prospects. Not only it can be to meet the need of current water treatment material, but also to open up new avenues for the rational use of cellulose, while the water treatment agent is expected to be biodegradable, which can accord with direction of development for the principle of 3R (Reduce, Reuse and Recycle) of "circular economy" and foundation of low energy consumption, low pollution-based "low-carbon economy" in nowadays.
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