Study On Preparation Of Walnuts Shell Activated Carbon And Its Properties

In the study, Walnuts shell biomass carbon was prepared by chemical activation with H3PO4 as activator. Using a single factor test to optimization the preparation conditions, obtain conditions for the preparation of walnut shell charcoal: ratio of walnuts shell and 50% H3PO4 is 1:3, dipping 60 min in the conditions of160 ℃,5 ℃ / min programmable up to450 ℃ as activation temperature for 60 min.Using low concentration HCl solution wash the activated carbon; The last, washed with distilled water untilneutral and dry under 100 ℃conditions.The characteristics of walnuts shell and walnuts shell biomass carbon were studied by SEM, XRD and FTIR Spectrometer. X-ray diffraction analysis showed that the carbonization process has transformed part of the crystalline regions to non-crystalline regions. FTIR Spectrometer showed that functional groups of walnuts shell have been oxidized. Study SEM found that walnuts shell surface was smooth, but walnuts shell biomass carbon surface was roughness and layered structure increased.Study on the adsorption of modified walnuts shell biomass carbon for alkaline dyes MG and MB, acidity dye PRM and Cu2+wastewater. The effect of experiment parameters, such as pH, temperature, contact time were examined. Furthermore, through the dynamics and thermodynamics model fitting to discussed adsorption mechanism. Adsorption alkaline dyes results showed that the best dosage of activated carbon was 1 g·L-1, adsorption MG pH was 5 to 9, and MB was 6 to 9. The adsorption thermodynamic of dyes followed the second-order model while the adsorption kinetics followed the Langmuir isotherm model. when the temperature was 318 K, MG mass concentration was 100mg·L-1, the removal rate reached 99.06%. The adsorption process is a spontaneous endothermic process; Adsorption MB results showed when the temperature was 303 K, MB mass concentration was 100mg·L-1, MB in the waster water removal rate reached 99.06%. The adsorption process is a spontaneous exothermic process; Adsorption PRM results showed that under natural pH conditions,when the temperature was 318 K, dosage of activated carbon was 2g·L-1,PRM mass concentration was 100mg·L-1, After 12 hours removal rate reached 99.61%. The adsorption thermodynamic of dyes followed the second-order model while the adsorption kinetics followed the Langmuir isotherm model. The adsorption process is a spontaneous endothermic process; Adsorption Cu2+ results showed that when the temperature was 318 K, pH conditions was 5,dosage of activated carbon was 1g·L-1, Cu2+mass concentration was 100mg·L-1, After 12 hours adsorpted 29.08mg·g-1. The adsorption thermodynamic followed the second-order model while the adsorption kinetics followed the Langmuir isotherm model. The adsorption process is a spontaneous endothermic process.