The spherical macroporous cellulose(SMC) was fabricated using medical absorbent cotton as raw material and nano CaCO3 as porogenic agents.And then,the phenylglycine was grafted onto the SMC to obtain the novel spherical macroporous cellulose derivative adsorbent(PSMC).FT-IR and scanning electron microscope(SEM) were employed to characterize the adsorbents and Fe3+ ions served as model solute to evaluate the adsorption property of the adsorbents.The experimental results show that the amount of porogenic agents and the value of pH have obvious influence on adsorption capacity of the adsorbents.The data of adsorption kinetic and isotherm display that the adsorbents possess excellent equilibrium adsorption capacity(348.94 mg/g) and have a bright prospect and considerable potential in the treatment of Fe3+ ions in wastewater.
Four novel benzothiazolium ionic liquids with 6PF?([C1Bth][PF6], [C4Bth][PF6], [C5Bth][PF6] and [C6Bth][PF6]) were synthesized, and the rang of their melting points were determined between 358.35 K-424.05 K. The relationship of their melting points and the length of the straight alkyl chain on cation reflected ‘S' type ten-dency. Then, the solubilities of the four ionic liquids in six lower alcohols(methanol, ethanol, 1-propanol, 2-propanol, 1-butanol and 2-methyl-1-propanol) were measured in the temperature rang of 253.15-383.15 K at at-mospheric pressure with static analytical method, respectively. It was found that [C6Bth][PF6] in all investigated ionic liquids had the largest solubility in six alcohols and the solubility of [C4Bth][PF6] in methanol was very sensi-tive for temperature in 313.15-333.15 K, which was so-called "temperature-sensitivity". This feature is of great significance to their application of catalyzing reaction or extraction process, and makes the recovery and reuse of ionic liquids(ILs) become easier. Moreover, the experimental solubility data were correlated with the modified Apelblat equation and λh equation, respectively. It was found that the result of correlation using two divided tem-perature ranges was better than that of using the whole temperature range.
An efficient porous spherical polyethyleneimine-cellulose(PEI-cell) absorbent was synthesized and characterized. The main influencing factors and adsorption mechanism for two typical metal ions, Cr3+and Fe3+, were investigated. The adsorption performance primarily depends on the initial concentration of metal ions, pH value and temperature, and the chelation action between N atoms of PEI-cell and metal ions plays an important role. Under dynamic adsorption conditions, the saturation adsorption of polyethyleneimine-cellulose is 83.98 mg·g-1for Cr(III) and 377.19 mg·g-1for Fe(III), higher than reported data and that of unmodified cellulose. The adsorption can be well described with second-order kinetic equation and Freundlich adsorption model, and ΔH, ΔG and ΔS of the adsorption are all negative. With 5%HCl as eluent, the elution ratio of Cr(III) and Fe(III) achieved 99.88% and 97.74% at 313 K, respectively.After the porous PEI-cell was reused 6 times, it still presented satisfactory adsorption performance.Above results show the advantages such as easily-acquired raw material, high efficiency, stable recycling performance and biodegradability.
