Preparation And Adsorption Properties Of Activated Carbon From Photosynthesis Bamboo

Heavy metal waste water from a series of industrial activities, once into the food chain and ingested by the body will cause serious toxic effects. At home and abroad had carried out extensive studies on the treatment of wastewater containing heavy metals. As an adsorbent material which the effect is obviously, activated carbon is widely used in heavy metal wastewater processed. However, the use of coal and other non-renewable resources to enable the preparation of activated carbon is costly. Today, the use of a wide range of sources of renewable agricultural and forestry waste preparing activated carbon have became many scholars' s focus. Photosynthetic bamboo as a new plant which used to deal with solid waste,massive planting and fast growth, high grass production, post-harvest waste more serious in the country south and north. Currently relevant to photosynthesis bamboo as raw material of activated carbon and heavy metal wastewater treatment research has not been reported,also provides a new way to the photosynthetic bamboo recycling use.In this paper, photosynthetic bamboo as raw material, prepared KOH / Na OH mixed activator activated carbon adsorbent material. Iodine and methylene blue adsorption and specific surface area as evaluation index, single factor experimental method examines the activation time, the base carbon ratio, activation temperature, KOH / Na OH ratio and the carbonization temperature influence factors on photosynthesis bamboo activated carbon adsorption properties.Activated carbon adsorbent material was characterized by surface area measurements,X-ray diffraction, Fourier transform infrared spectroscopy(FT-IR), Boehm titration and scanning electron microscopy(SEM). Activated carbon surface by chemical oxygen-containing functional groups qualitative analysis to study the physical and chemical properties of photosynthetic bamboo charcoal; combining adsorption kinetics of adsorption time, the impact of the activated carbon dosage, p H and the reaction temperature on the adsorption of Cd(?) Effect. The main conclusions are as follows:(1) Photosynthesis bamboo activated carbon raw material, first by KOH, Na OH, KOH /Na OH three kinds activator research compared the index of methylene blue and iodine adsorption value, combining the specific surface area to finalize the KOH / Na OH photosynthetic bamboo preparation activated carbon is the best activator. Single factor experiment to determine the optimal preparation conditions: charring 30 min with the carbonization temperature 400 ?, alkali carbon ratio is 3: 2, KOH and Na OH ratio is 3: 1,the immersion time 5 h, activation time 60 min, activation temperature 650 ?. Under the optimum conditions, the activated carbon adsorption value of methylene blue is 202.5mg/g,iodine adsorption value is 1255.5 mg/g. Experimental study found that Cd(?) concentration of 10-150mg/L with Langmuir than Freundlich isotherm fit better balance data for the monolayer adsorption, the maximum amount of adsorption of cadmium ions 25.575 mg / g.(2) Through BET and Langmuir surface area test, N2 adsorption- desorption isotherms,obtain BJH analysis mesoporous and microporous T diagram analysis. Research shows under optimal conditions, the photosynthetic bamboo activated carbon specific surface area is2343.9m2/g, average pore diameter of the adsorption 1.787 nm, a total pore volume is0.902cm~3/g, micropore volume 0.7971cm~3/g, large aperture ratio is 4.97%, dielectric aperture ratio is 59.64%, the proportion of micropores aperture is 35.39%. the activated carbon can produce more porous, larger pores and volume of mesoporous when KOH and Na OH at the ratio 3:1,which can obviously enhance the adsorption performance. The surface of the activated carbon was observed by scan electron microscope; XRD-ray diffraction analysis showed that the photosynthetic bamboo activated carbon is graphite crystallites based amorphous carbon material. Make use of boehm titration combined with Fourier transform infrared spectroscopy(FTIR), qualitative and quantitative method to analysis carbon surface chemistry of oxygen-containing functional groups. the results showed that after the KOH /Na OH composite activated carbon surface has increased the number of oxygen-containing basic groups especially hydroxyl functional group.(3)Photosynthesis Bamboo activated carbon was prepared to absorb cadmium-containing waste water. concentrations of 20mg/L, 50mg/L, 100mg/L which containing Cd(?) heavy metal wastewater adsorbed and compared by activated carbon which prepared undering optimum conditions. Mainly on the adsorption time, the impact of the activated carbon dosage,p H and the reaction temperature on the adsorption effect of cadmium. The results found that with increasing cadmium concentration in the solution, activated carbon dosage increases,unit mass activated carbon adsorpt volume growth was ebbing slowly; adsorption equilibrium time of 30 min is appropriate, room temperature(25?) and PH value of 7 are conducive to photosynthesis bamboo charcoal adsorption of cadmium, the removal rate around 99%.first-order kinetics and secondary kinetic equation modeling are used to fit, results showed that quasi- second-order kinetic model fit the adsorption equilibrium data well, models correlation coefficient reach 0.999 or more. Experimental study found that Langmuir fit better balance data than Freundlich isotherm in Cd(?) concentration of 10-150mg/L range, the activated carbon is monolayer adsorption, the maximum amount of adsorption of cadmium ions is 25.575mg/g.