The removal of phosphate from aqueous solution by Donnan dialysis with anion-exchange membrane was investigated.The results show that phosphate could be removed from aqueous solution without supplying external high pr...The removal of phosphate from aqueous solution by Donnan dialysis with anion-exchange membrane was investigated.The results show that phosphate could be removed from aqueous solution without supplying external high pressure or electrical potential.Under the conditions of influent phosphate of 2.0 mg/L,counterion(Cl-)concentration of 0.1 mol/L,stirring speed of 500 r/min and phase temperature of 298 K,the removal of phosphate achieves 70.0%.Decreasing counterion concentration has little influence on the removal of phosphate,but phosphate amount in anion-exchange membrane increases significantly.With the increase of stirring speed and phase temperature,the removal efficiency of phosphate greatly is improved.Existing forms of phosphate in aqueous solution affected transport of phosphate and only strong acidic pH of feed solution(pH=3.0)decreases the removal of phosphate.Transport of phosphate is also accompanied by change of pH value of feed solution.In consequence,it might be a promise potential process for phosphate advanced wastewater treatment,especially in the area where high salted nature water can be utilized.展开更多
This study was focused on orthophosphate adsorption on natural zeolite which was obtained from South of Thailand and has been carried out by Vanadomolybdophosphoric Acid （VMPA） and using spectrophotometry technique....This study was focused on orthophosphate adsorption on natural zeolite which was obtained from South of Thailand and has been carried out by Vanadomolybdophosphoric Acid （VMPA） and using spectrophotometry technique. The phosphate solution were prepared artificially by adding certain quantities of KH2PO4 in water at the initial orthophosphate concentration of 5, 10 and 20 mg/L. While the adsorbent quantity was 1g of natural zeolite per 50 mL, aqueous solution NaOH IN and HCI IN solutions were used as pH regulators. The effect of equilibrium pH, adsorbent mass and contact time was studied. The results showed that natural zeolite adsorption efficiency was 99.18%, 99.33% and 99.02% （5, 10 and 20 mg/L）, respectively, at pH of 12 and a contact time of 30 minutes at 298 K. Moreover, the isotherm can be used to evaluate the capacity and nature of the interaction between a sorbent and a sorbate. This work considers the Langmuir and Freundlich isotherm. Based on the R2 of adsorption isotherm studies, the adsorption data for phosphate fitted well the Freundlich isotherm for natural zeolite （R^2=0.99）, with multi-layer adsorption. The results are in good agreement with recent experimentl data.展开更多
基金Project(50778065)supported by the National Natural Science Foundation of China
文摘The removal of phosphate from aqueous solution by Donnan dialysis with anion-exchange membrane was investigated.The results show that phosphate could be removed from aqueous solution without supplying external high pressure or electrical potential.Under the conditions of influent phosphate of 2.0 mg/L,counterion(Cl-)concentration of 0.1 mol/L,stirring speed of 500 r/min and phase temperature of 298 K,the removal of phosphate achieves 70.0%.Decreasing counterion concentration has little influence on the removal of phosphate,but phosphate amount in anion-exchange membrane increases significantly.With the increase of stirring speed and phase temperature,the removal efficiency of phosphate greatly is improved.Existing forms of phosphate in aqueous solution affected transport of phosphate and only strong acidic pH of feed solution(pH=3.0)decreases the removal of phosphate.Transport of phosphate is also accompanied by change of pH value of feed solution.In consequence,it might be a promise potential process for phosphate advanced wastewater treatment,especially in the area where high salted nature water can be utilized.
文摘This study was focused on orthophosphate adsorption on natural zeolite which was obtained from South of Thailand and has been carried out by Vanadomolybdophosphoric Acid （VMPA） and using spectrophotometry technique. The phosphate solution were prepared artificially by adding certain quantities of KH2PO4 in water at the initial orthophosphate concentration of 5, 10 and 20 mg/L. While the adsorbent quantity was 1g of natural zeolite per 50 mL, aqueous solution NaOH IN and HCI IN solutions were used as pH regulators. The effect of equilibrium pH, adsorbent mass and contact time was studied. The results showed that natural zeolite adsorption efficiency was 99.18%, 99.33% and 99.02% （5, 10 and 20 mg/L）, respectively, at pH of 12 and a contact time of 30 minutes at 298 K. Moreover, the isotherm can be used to evaluate the capacity and nature of the interaction between a sorbent and a sorbate. This work considers the Langmuir and Freundlich isotherm. Based on the R2 of adsorption isotherm studies, the adsorption data for phosphate fitted well the Freundlich isotherm for natural zeolite （R^2=0.99）, with multi-layer adsorption. The results are in good agreement with recent experimentl data.
