Modification Of Cellulose Hydrogel And Heavy Metal Adsorption Studies Of A Novel

With the development of human economic activities and the progress of science and technology,the pollution of water environment becomes more seriously. What is more, sewage contains a lot of organic dyes and heavy metal ions which is difficult to degradae. Due to the complex chemical structure of dye,the general biochemical treatment can not make dye meet the discharge standard. And because of biological accumulation of heavy metal ions,it is easy to enter human body through food chain. Now the pollution of water environment is threat to our health seriously, the removal of heavy metal ions and organic dye is looming ahead. Adsorption method has been a research focus in sewage treatment, the choice of the adsorbent for adsorption effect always plays an important role. Most adsorbents have common disadvantages of recycle and degradae with difficulty. So the purpose of this research is to seek a kind of magnetic cellulose hydrogel with simple preparation, good adsorption effect to heavy metal ions and organic dyes, easily recycling and degradaing, and also find a new way to solve the problem of water pollution。This research selects the acrylic acid(AA) and acrylamide(AM) as monomers, potassium persulfate as initiator, N,N-methylene double acrylamide as crosslinking agent by solution polymerization to make cellulose hydrogel grafted and composite γ-Fe2O3 nanoparticles. Then the magnetic cellulose hydrogel was composited and cellulose hydrogel was modificated. Through SEM, FT-IR, TG, Roman, we can know that the magnetic cellulose hydrogel has been composited successfully. SEM shows that the magnetic cellulose hydrogel has channel and the three-dimensional network structure. FT-IR analysis and Roman analysis proves that the hydrogel successfully grafted acrylic acid and acrylamide monomer, and composite γ-Fe2O3 particles. TG analysis confirmed that the hydrogel has good thermal stability.Aim at synthesis condition, we mainly consider four factor: the mass of AA/AM, the mass of γ-Fe2O3, reaction temperature, and reaction time. Through adsorption effect of Cu2+, Co2+, Cr3+, malachite green, methylene blue, we find that the best synthesis condition is mass of AA/AM is 6.0 g, the mass of γ-Fe2O3 is 0.4 g, reaction temperature is 20℃ and reaction time is 2.0 h when fiber dosage and pasting conditions is certain. Adsorption capacity of Cu2+, Co2+, Cr3+, malachite green, methylene blue is 0.6800 mmol/g 、0.3885 mmol/g、0.4766 mmol/g 、158.6569 mg/g、130.8059 mg/g。Throuhg hydrogel dosage, oscillation time, adsorption kinetics and adsorption isotherm, p H, we study the adsorption behavior of heavy metal ions. We can find that, the best dosage of magnetic hydrogels is 0.1000 g when facing the heavy metal ion concentration is 0.05 mol/L.And when the dosage under a certain situation, the adsorption rates followed the order Cr3+>Co2+>Cu2+. We aslo can ger that the suitable time is 2.0 h. The adsorption kinetics of Cu2+, Co2+, Cr3+ followed pseudo-second-order kinetic model, the adsorption rate wascontrolled by chemical adsorption, and the adsorption rates followed the order Cr3+>Co2+>Cu2+. As to isotherm, Cu2+ fitted Freundlich model better, Co2+ fitted Langmuir model better,Cr3+ fitted Henry model better. Initial p H of the research shows that the adsorption quantity of Cu2+, Co2+, Cr3+ is very small almost zero when p H = 1 ~ 2, the adsorption quantity increased rapidly when p H = 2 ~ 4, adsorption quantity increases, but relatively slow when p H = 4 ~ 6.Throuhg hydrogel dosage, oscillation time, adsorption kinetics and adsorption isotherm, p H, we study the adsorption behavior of organic dyes. We can find that, the best dosage of magnetic hydrogels is 0.0250 g when facing the organic dyes concentration is 400 mg/L.And when the dosage under a certain situation, the adsorption rates followed the order malachite green>methylene blue. We aslo can ger that the suitable time is 1.0 h. The adsorption kinetics of malachite green, methylene blue followed pseudo-second-order kinetic model and the adsorption rates followed the order malachite green> methylene blue. As to isotherm, malachite green, methylene blue both fitted Henry model better. Initial p H value has an impact on adsorption quantity of malachite green and methylene blue, but the impact is not big.