The Study On Bamboo Activated Carbon Prepared By Bamboo Chip And Its Adsorptive Mechanism

Shortages of resource and environment pollution are two major problems in the development process of society.Resource recovery is not only resource-saving and environment-protection but creating considerable economical benefit.The bamboo resource in China is abundant,but the utilization is so low.Studying new bamboo products by using spare bamboo chip that comes from bamboo industry could not only change the waste into treasure and creating great economical benefit,but relieve the shortage of wood resource in our country.The main content of this paper included the preparation of bamboo activated carbon and its absorption capability.The bamboo chip was immersed in the phosphoric acid liquor and potassium hydroxide liquor respectively,and then calcined and activated under high temperature. According the absorption of methylene blue,the research found out the optimum preparing condition of bamboo activated carbon by phosphoric acid and potassium hydroxide with orthogonal test,and the effect of time,pH and concentration on bamboo activated carbon to absorption of methylene blue,acid fuchsin and Cd2+. As mentioned above,the paper also studied the absorption of vitamin B12.Finally,the structure of bamboo activated carbon was characterized.The results are shown as follows:(1)According to the absorption of methylene blue,the optimum preparing condition of bamboo activated carbon by phosphoric acid is:the concentration of phosphoric acid is 6.0mol/L,the time of immersion is 12h,the temperature of carbonization is 700℃and the time of carbonization is 1.5h. The optimum preparing condition of potassium hydroxide of bamboo activated carbon is:the concentration of potassium hydroxide is 1.5mol/L,the time of immersion is 48h,the temperature of carbonization is 700℃and the time of carbonization is 1.5h.(2)According to the absorption of vitamin B12,the optimum preparing condition of bamboo activated carbon by phosphoric acid and potassium hydroxide is the same as the optimum preparing condition of bamboo activated carbon that according to the absorption of methylene blue.(3)The best absorption time of acid-processed and alkaline-processed bamboo activated carbon to methylene blue is 2h,and that of wooden activated carbon is 2.5h.The absorption of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon is best at pH 8 around.According to the Langmuir isotherm formula, the peak absorption of acid-processed and alkaline-processed bamboo activated carbon, wooden activated carbon to methylene blue is 625.00mg/g,555.56 mg/g and 500.00mg/g respectively.(4)The best absorption time of alkaline-processed bamboo activated carbon to acid fuchsin is 2h,and acid-processed bamboo activated carbon and wooden activated carbon is 2.5h.The absorption of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon is best at pH 6 around.According to the Langmuir isotherm formula, the peak absorption of acid-processed and alkaline-processed bamboo activated carbon, wooden activated carbon to acid fuchsin is 434.78mg/g,416.67mg/g and 588.23mg/g respectively.(5)The best absorption time of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon to Cd2+is 7h.The absorption of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon is best at pH 6 around.According to the Langmuir isotherm formula,the peak absorption of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon to Cd2+is 89.29mg/g,86.21 mg/g and 99.01mg/g respectively.(6)The best absorption time of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon to vitamin B12 is 2h,2.5h and 3.5h.The absorption of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon is best at pH 4-5.The absorption of alkaline-processed bamboo activated carbon and wooden activated carbon are better than acid-processed bamboo activated carbon. According to the Langmuir isotherm formula,the peak absorption of acid-processed and alkaline-processed bamboo activated carbon,wooden activated carbon to vitamin B12 is 37.74mg/g,158.73mg/g and 303.03mg/g respectively.(7)The absorption of wooden activated carbon to iodin is 758 mg/g,the acid-processed and the alkaline-processed bamboo activated carbon to iodin is 673 mg/g and 695 mg/g respectively.(8)The oxygen-containing groups of acid-processed bamboo activated carbon are more than the alkaline-processed activated carbon,and the nonpolar groups of acid-processed bamboo activated carbon are less than the alkaline-processed activated carbon.The oxygen-containing groups of wooden activated carbon are more and all stronger polar,so the absorption of it is high to polar organic and heavy metal ions.(9)The surface area of wooden activated carbon,acid-processed and alkaline-processed bamboo activated carbon is 1289.6520m2/g,1189.4132 m2/g and 940.0803m2/g respectively. The pore volume of wooden activated carbon,acid-processed and alkaline-processed bamboo activated carbon is 1.054477cm3/g,0.752351cm3/g and 0.550500cm3/g respectively. The pore width of wooden activated carbon,acid-processed and alkaline-processed bamboo activated carbon is 32.7058A,25.3016A and 23.4235A respectively. The mespores of wooden activated carbon are more than bamboo activated carbon.The microporous of bamboo activated carbon are more.