A fibrous strong base anion exchanger （QAPPS） was prepared for the first time via chloromethylation and quaternary amination reaction of polyphenylene sulfide fiber （PPS）, and its physical-chemical structure and a...A fibrous strong base anion exchanger （QAPPS） was prepared for the first time via chloromethylation and quaternary amination reaction of polyphenylene sulfide fiber （PPS）, and its physical-chemical structure and adsorption behavior for Cr（VI） were characterized by FT- IR, Energy Dispersive Spectrometry, TG-DTG, elemental analysis and batch adsorptive technique, respectively. The novel fibrous adsorbent could effectively adsorb Cr（VI） over the pH range 1-12, the maximum adsorption capacity was 166.39 mg/g at pH 3.5, and the adsorption behavior could be described well by Langmuir isotherm equation model. The adsorption kinetics was studied using pseudo first-order and pseudo second-order models, and the 4/2 and equilibrium adsorption time were 5 and 20 min respectively when initial Cr（VI） concentration was 100 mg/L. The saturated fibers could be regenerated rapidly by a mixed solution of 0.5 mol/L NaOH and 0.5 mol/L NaCl, and the adsorption capacity was well maintained after six adsorption-desorption cycles.展开更多
The effects of dissolved organic matter （DOM） on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic ...The effects of dissolved organic matter （DOM） on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic acid concentration from 0 to 400 mg/L, the adsorption amount of nitrate-nitrogen on the commercial resins, including D201, Purolite A 300 （A300） and Purolite A 520E （A520E）, would significantly decrease. However, the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them. Compared to D201 and A300 resins, A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules, such as gallic acid and tannin acid at greater levels in aqueous solution. Attractively, the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Fretmdlich equations. The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations. In batch adsorption processes, nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t1/2 rather than the contact time. The pseudo first- and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin. The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater.展开更多
基金support of the National Natural Science Foundation of China (No. 20574063,21004055)
文摘A fibrous strong base anion exchanger （QAPPS） was prepared for the first time via chloromethylation and quaternary amination reaction of polyphenylene sulfide fiber （PPS）, and its physical-chemical structure and adsorption behavior for Cr（VI） were characterized by FT- IR, Energy Dispersive Spectrometry, TG-DTG, elemental analysis and batch adsorptive technique, respectively. The novel fibrous adsorbent could effectively adsorb Cr（VI） over the pH range 1-12, the maximum adsorption capacity was 166.39 mg/g at pH 3.5, and the adsorption behavior could be described well by Langmuir isotherm equation model. The adsorption kinetics was studied using pseudo first-order and pseudo second-order models, and the 4/2 and equilibrium adsorption time were 5 and 20 min respectively when initial Cr（VI） concentration was 100 mg/L. The saturated fibers could be regenerated rapidly by a mixed solution of 0.5 mol/L NaOH and 0.5 mol/L NaCl, and the adsorption capacity was well maintained after six adsorption-desorption cycles.
基金supported by the Program for Changjiang Scholars Innovative Research Team in University and NS-FC (No.50938004,51178215,51008152)the Jiangsu Nature Science Foundation for Distinguished Scientists(No.BK2010006, BK2011032)the Scientific Research Starting Found for Postdoctors,Nanjing University(No.0211003046, 021114340069)
文摘The effects of dissolved organic matter （DOM） on the removal of nitrate-nitrogen from the model contaminated water have been investigated utilizing the strong base anion exchange resins. With the increase of gallic acid concentration from 0 to 400 mg/L, the adsorption amount of nitrate-nitrogen on the commercial resins, including D201, Purolite A 300 （A300） and Purolite A 520E （A520E）, would significantly decrease. However, the presence of tannin acid has little impact on nitrate-nitrogen adsorption on them. Compared to D201 and A300 resins, A520E resin exhibited more preferable adsorption ability toward nitrate-nitrogen in the presence of competing organic molecules, such as gallic acid and tannin acid at greater levels in aqueous solution. Attractively, the equilibrium data showed that the adsorption isotherm of nitrate-nitrogen on A520E resin was in good agreement with Langmuir and Fretmdlich equations. The rate parameters for the intra particle diffusion have been estimated for the different initial concentrations. In batch adsorption processes, nitrate-nitrogen diffuse in porous adsorbent and rate process usually depends on t1/2 rather than the contact time. The pseudo first- and the second-order kinetic models fit better for nitrate-nitrogen adsorption onto A520E resin. The observations reported herein illustrated that A520E resin will be an excellent adsorbent for enhanced removal of nitrate-nitrogen from contaminated groundwater.
