Preparation Of Aminoalky Cellulose And Its 2, 4, 6-Trinitrotoluene Adsorption Capacity

With the rapid development of 2, 4, 6-trinitrotoluene industries (TNT) and its wide applications in civil and military fields, the pollution of TNT becomes more and more serious, which destroy the environment and affect human health. Water source pollution of TNT wastewater has already become serious problems that influence the survival environment of human and other creatures. It will have wide application prospect in environment protection, resources recovery and reclamztion to find a good and cheap adsorbent, which are both environmental friendly and can adsorb TNT effectively. In this thesis, aminoalky cellulose that fuction as adsorption and separation was prepared and characterized by FT-IR, 13C-NMR, SEM etc. the adsorption performance of aminoalky cellulose for TNT was investigated by static experiment and fixed bed experiment.Hydroxyethyl cellulose (HEC) was used as the raw material, and aminoalky cellulose (AmAC) had been synthesized by two steps reaction, as follows: chloridization and aminoalkylization. Thionyl chloride and ethanediamine was used as chlorating agent and aminating agent, respectively. The optimal ratio of 4:1(mL: g) between thionyl chloride and HEC in process of preparing chloro-deoxy-hydroxyethlcellulose was determined by single factor experiments, and the chlorine content of CDHC could reach up to 23.245%. In process of preparing AmAC, The optimal condition was determined by orthogonal experiments and single factor experiments, and the optimal condition could be stated, as follows: temperature of 80°C, the ratio of 15:1 (mL: g) between ethanediamine and CDHC, reaction time of 10 hours.The physical and chemical structures of HEC, CDHC and AmAC were charactered by varying Modern analytical methods. The results showed that apparent morphology of AmAC was white powder, and AmAC was amorphous structure. Particle size range of AmAC was 50-100 um. The rough surface of AmAC could be observed through the scanning electron microscope. The water absorption performance of AmAC was determined, and the result showed that water absorption dosage was 25% of dry weight. Zeta potential of AmAC in water was -7.2 mV.The adsorption performance of AmAC for TNT was investigated through adsorption static experiment and fixed bed experiment. The effect of varying adsorption parameters, such as pH, temperature, adsorbent dosage, adsorption time and initial concentration, on adsorption performance was investigated through static experiments. The result of static experiments showed that AmAC possed strong adsorption ability for TNT with adsorption amount of 69.19 mg/g and removal efficiency of 99.30%. The pH had a great effect on the adsorption ability of AmAC for TNT, and the absorption capacity was lower in acidic and alkaline solutions than that in neutral solutions. The possible mechanisms for AmAC absorbing TNT were discussed under varying pH and temperature. Also the result of the reusability experiment showed the adsorbed TNT could bedesorbed by ethanol.The fixed bed experiment was conducted in order to investigate dynamic adsorption performance for TNT.the fixed bed was filled with AmAC, and the TNT could be adsorbed due to the inlet TNT solution from bottom and the outlet TNT solution from top. The adsorption parameter, such as inlet TNT concentration, flowrate and bed height, was studied through the fixed bed experiments. The breakthrough curve was fitted with Thomas model and Yoon-Nelson model. The result of BDST model showed that the minimum bed height was 2.43 cm with the flowrate of 10 mL/min and the inlet concentration of 20 mg/L.