Study On Adsorption Of Heavy Metals And Phenol By Radiation Graft Copolvmerization Of Cellulose And NVP

With the increasing discharge of industrial wastewater, it causes great harm to the environment andhealth, therefore the industrial wastewater needs to be dealt with reasonably before discharge. Celluloseis the main component of agricultural waste materials with wide sources and low price, but its capacityof treatment of wastewater is limited, so the cellulose needs to be treated with a proper graftingmodification. Currently the modified methods about cellulose mainly focus on the chemical methods,and less research on radiation grafting methods. The radiation grafting technology is mainly applied tothe polysaccharide molecular modification and synthesis of medical polymeric materials, its use ofhigh-energy radiation irradiates a polymer to produce free radicals, triggering another monomer andpolymer free radical polymerization reaction, forming a grafting copolymer. Radiation graftingtechnology needs no initiator, no residue, and can form free radicals throughout the solid fiber, it cancomplete the grafting reaction that the chemical method is difficult to carry out, and the operation issimple and easy, has advantages that chemical grafting method can not compare. Therefore,this paperused cellulose as the substrate, N-vinyl pyrrolidone as monomers, prepared cellulose-N-vinylpyrrolidone radiation grafting copolymer by total radiation method, studied the irradiation dose,NVP/cellulose mass ratio, deionized water amount on the yield that the effects of grafting yield, anddiscussed effect of each factor on the grafting yield by orthogonal test method. And the swellingperformance and adsorption of cd²⁺, pb²⁺and phenol of cellulose-N-vinyl pyrrolidone radiation graftingcopolymer were aslo studied. The results showed that:（1） Cellulose and NVP occurred grafting copolymerization, and the copolymer retained thelactam structure of NVP. The grafting reaction improved the thermal stability of cellulose.（2） The optimum process conditions for preparation of cellulose-N-vinylpyrrolidone radiationgrafting copolymer: irradiation dosage8kGy, the use level of deionized water4mL and NVP/cellulosemass ratio4:1, the grafting yield of obtained grafting copolymer was354.8%. The mass ratio ofNVP/cellulose played a leading role, followed by radiation dose, finally is the use level of deionizedwater.（3） The grafting reaction improved the capacity of absorbent swelling, and the swelling isproportional to the grafting yield, when the grafting yield was656.4%, the equilibrium swelling ratioreached4301%. And to some extent, the grafting reaction improved the salt tolerance andoverwhelmingly promoted the capacity of holding water of cellulose.（4） When the grafting yield of cellulose-N-vinyl pyrrolidone was219.1%, it has a good effect onadsorption for cd²⁺, pb²⁺and phenol, and the adsorption process was abided by quasi second orderkinetic adsorption model.（5） When in the near-neutral condtions, cellulose-N-vinyl pyrrolidone radiation graftingcopolymer adsorption of cd²⁺and pb²⁺made a better adsorption effect,and the best pH value foradsorption of cd²⁺was6, and pb²⁺was5, this moment the adsoption capacity was respectively 11.280mg/g and11.006mg/g. Its absorption of cd²⁺, pb²⁺and phenol can achieve a optimal adsorptioneffect by0.1g cellulose-N-vinyl pyrrolidone radiation grafting copolymer. While the initialconcentration of cd²⁺, pb²⁺and phenol was higher, it would achieve a greater adsorption capacity.（6） Cellulose-N-vinyl pyrrolidone radiation grafting copolymer adsorption of cd²⁺, pb²⁺andphenol obeyed the Freundlich isotherm adsorption equation. The thermodynamic parameters showedthat the Cellulose-N-vinyl pyrrolidone radiation grafting copolymer adsorption of cd²⁺, pb²⁺can bespontaneous and belonged to the exothermic process.