Research Of Adsorption Of LG And AK From Aqueous Solution By CTAB And CPB Modified Peanut Hull

Two new adsorbents (CTAB-PH and CPB-PH), were prepared through Cetyltrimethyl Ammonium Bromide (CTAB) and Cetyl Pyridinium Bromide (CPB) modified peanut hull, respectively. The natural peanut hull, CTAB-PH and CPB-PH were all analyzed by the means of essential element analysis, XRF, FTIR and XRD. The adsorption of light green (LG) and acid chrome blue (AK) onto CTAB-PH and CPB-PH were performed, respectively. Results showed that both of CTAB and CPB had been introduced into the structure of peanut hull and there was higher adsorption capacity of LG and AK onto CTAB-PH and CPB-PH than that of untreated peanut hull.The adsorption processes of LG and AK, based on the CTAB-PH and CPB-PH, were operated by two ways:batch and fixed adsorption modes. The influence of various experimental conditions, such as adsorbent dosage, reacting time, dye concentration, pH, coexisting ions and temperature were studied in batch adsorption. Results showed that adsorption capacity of unit mass of adsorbents were optimal of LG and AK onto CTAB-PH and CPB-PH when the pH of solution was3. Moreover, the presence of Na+and Ca2+decreased the adsorptive ability for LG, but slightly increased for AK. The adsorption capacity of LG and AK onto CTAB-PH were140mg-g-1and130mg-g-1, while88mg-g-1and93mg-g-1onto CPB-PH at303K, respectively. The adsorptions of LG and AK onto CTAB-PH and AK onto CPB-PH were endothermic while LG onto CPB-PH was exothermal. In the study of dynamic adsorption of all the four systems, effects of bed depth, flow rate of solution, original concentration of dyes and pH were also investigated.All adsorptions of the modified peanut hulls were spontaneous. There was no significant change in the chemical construction of adsorbent. The equlibrium data for all of the four systems were fitted best by the Redlich-Peterson isotherm models. In the surface dynamics analysis, the Elovich-type equation was a wonderful way of describing the four adsorption behaviors, while the Yan model was the best choice to describe the column adsorption process.The regeneration researches were also presented. The results showed thatNaOH (0.01mol-L-1solution was excellent to desorb the LG from CTAB-PH and CPB-PH can be reused after regeneration and the unit adsorption quantity was improved. Microwave treatment is a preferable way to regeneration of AK-loaded adsorbents. The dye-loaded adsorbents can be reused after regeneration.