The pretreatment for the removal of small molecules from poly(acrylic acid) sodium (PAAS) solution by continuous diafiltration was investigated using ultrafiltration membrane. The effects of PAAS concentration, pH, tr...The pretreatment for the removal of small molecules from poly(acrylic acid) sodium (PAAS) solution by continuous diafiltration was investigated using ultrafiltration membrane. The effects of PAAS concentration, pH, trans-membrane pressure and pretreatment time on the permeate concentration and permeate flux were studied. The results show that the necessary pretreatment time (NPT) increases with PAAS concentration, decreases with TMP. The change trend of permeate flux with time is affected by pH. The permeate fluxes rapidly decrease from the start, and then increase gradually to stable values at pH 5.0, pH 7.0 and pH 9.3. However, it decreases gradually with time till a state value at pH 3.0 (iso-electric point, IEP). The removal of small molecules is easy at pH greater than iso-electric point (IEP). The change of filtration potential with time indicates the similar trend to that of permeation concentration, but the former is more convenient for indication of NPT.展开更多
Poly(acrylic acid-co-acrylamide)(PAAAM)resin was prepared from acrylic acid(AA)and acrylamide(AM)by inverse suspension polymerization.The adsorption of metal ions on PAAAM resin differed greatly at different pH values...Poly(acrylic acid-co-acrylamide)(PAAAM)resin was prepared from acrylic acid(AA)and acrylamide(AM)by inverse suspension polymerization.The adsorption of metal ions on PAAAM resin differed greatly at different pH values and initial concentrations.This provided a theoretical basis for the application of PAAAM resin to separate transitional metal ions Cu2+,Ni2+,Co2+.The selectivity for competitive adsorption on PAAAM resin in Cu2+,Ni2+ and Co2+ binary and ternary mixed ion solutions were investigated.It was found that there was higher selectivity on PAAAM resin for Cu2+ ions compared with other metal ions used in this study.展开更多
基金Projects(21176264,21476265)supported by the National Natural Science Foundation of China
文摘The pretreatment for the removal of small molecules from poly(acrylic acid) sodium (PAAS) solution by continuous diafiltration was investigated using ultrafiltration membrane. The effects of PAAS concentration, pH, trans-membrane pressure and pretreatment time on the permeate concentration and permeate flux were studied. The results show that the necessary pretreatment time (NPT) increases with PAAS concentration, decreases with TMP. The change trend of permeate flux with time is affected by pH. The permeate fluxes rapidly decrease from the start, and then increase gradually to stable values at pH 5.0, pH 7.0 and pH 9.3. However, it decreases gradually with time till a state value at pH 3.0 (iso-electric point, IEP). The removal of small molecules is easy at pH greater than iso-electric point (IEP). The change of filtration potential with time indicates the similar trend to that of permeation concentration, but the former is more convenient for indication of NPT.
文摘Poly(acrylic acid-co-acrylamide)(PAAAM)resin was prepared from acrylic acid(AA)and acrylamide(AM)by inverse suspension polymerization.The adsorption of metal ions on PAAAM resin differed greatly at different pH values and initial concentrations.This provided a theoretical basis for the application of PAAAM resin to separate transitional metal ions Cu2+,Ni2+,Co2+.The selectivity for competitive adsorption on PAAAM resin in Cu2+,Ni2+ and Co2+ binary and ternary mixed ion solutions were investigated.It was found that there was higher selectivity on PAAAM resin for Cu2+ ions compared with other metal ions used in this study.
