Preparation Of Cationic Cellulose And The Study On Its Flocculation And Dye-adsorption Behavior

Cellulose is the most abundant organic matters in the nature, and contains many hydroxyls in its molecular chain. The cellulose properties can be changed through hydroxylation such as esterification, etherification, oxidation and crosslinking. Cellulose derivatives take on many characters inherited from natural polymers, including nonpoisonous, completely biodegradation and soundly recyclation in nature, etc; and also many special characters. These special characters make cellulose derivatives play important roles in commodities, papermaking, textile, foods, dyestuffs, pharmacy, wastewater treating, adherence and exploitation of gasoline, etc. For the drying-up petroleum and coal, serious energy source exhaustion scrisis and environmental pollution, R&D and application of cellulose derivatives have attracted a lot of attention.Cationic cellulose takes on superior properties in wastewater treating because of its cationic groups. In this paper we have synthesised several cationic cellulose with different degrees of substitution(DS). Further more, we apply these samples as flocculants and dye absorbents in wastewater treatments. The main conclusions are showed below:(1)The cationic cellulose were synthesised with cellulose and 2,3-epoxypropyl- trimethylammonium. (a) A higher DS cationic cellulose was homogeneously synthesised in NaOH/Urea aqueous soluton. The 13C-NMR spectrum showed a more uniform distribution of the substituents on glucose unit. (b) A water insoluble cationic cellulose was synthsised with a slurry system. The degrees of substitution of them are more lower than that with the homogeneous method.(2)The flocculation result of cationic cellulose samples with different DS under homogeneous system at different pH were taken out in kaolin suspension, which simulated wastewater. The experiments results demonstrated that as a flocculant the cationic cellulose showed a enough flocculation capacity at a wide pH range, especially under neutral and alkaline conditions. And its main flocculation mechanism was neutralization and bridged adsorption.(3)The cationic cellulose synthsised in slurry system could use as dye adsorbent. We have used it to adsorb three kinds of anionic dyes(Orange II, Acid Red 18, Acid Blue 92), and took out a outstanding sesults. The maximum adsorption quantity could be to 465mg/g. And the ratios of dye adsorption were all over 90% with the initial dye concentration of no more than 1mmol/L. And the main adsorption mechanism was electrostatic adsorption with a single layer .