氧化石墨烯/聚哌嗪酰胺复合纳滤膜在染料脱除中的应用研究

Applied research of graphene oxide polypiperazine-amide composite nanofiltration membrane in removal of dye wastewater

采用界面聚合的方法制备抗污染的氧化石墨烯(GO)改性聚酰胺(PA)复合纳滤膜(GOPA),并对其在脱除染料中的应用进行研究.以哌嗪(PIP)、氧化石墨烯(GO)混合分散液作为水相,均苯三甲酰氯(TMC)的正己烷溶液作为有机相,在聚醚砜(PES)超滤膜支撑层上采用界面聚合的方法制备复合纳滤膜(GO-PA).通过表征,确认膜表面呈荷负电性,平均孔径0.4nm左右,截留相对分子量774左右.在0.6MPa的操作压力下,膜的纯水通量可达87.6L/(m^2·h),对无机盐的截留率为:Na_2SO_4(98.2%)>MgSO_4(96.5%)>NaCl(56.8%)>MgCl_2(50.5%).复合膜的抗污染性实验结果表明,GO-PA膜的抗污染性能明显提高.最后,通过考察复合膜对酸性红、直接黑、直接黄三种染料的去除效果.结果表明,所制备的GO-PA复合膜对3种染料的截留率达到98%以上.

The anti-fouling graphene oxide modified polyamide composite nanofiltration membranes （GOPA） were prepared through trimesoyl chloride （TMC） reacting with the GO dispersion in piperazine （PIP） aqueous solution via interracial polymerization （IP） on the polyethe/, sulfone （PES） UF substrates, and the prepared composite nanofiltration membrane was applied in removal of dye wastewater. The characterization results indicated that the negative charged membrane was successfully fabricated, and the mean effective pore size and the molecular weight cut-off （MWCO） were about 0. 4 nm and 774 Da respectively. The pure water flux was 87. 6 L/（m2 · h） under the operating pressure of 0. 6 MPa, and the salt rejections of the membrane decreased in the order Na2SO4 （98. 2%） 〉 MgSO4 （96. 5%）;〉NaCl （56.8%）〉MgCl2 （50. 5%）. Fouling resistances of the membranes results revealed that the GO-PA membrane had improved the antifouling properties. The removal of the Silk Scarlet （GR GR）, Direct Black 22 （DB）, Sun Yellow （SY） was investigated in this study, the results suggested that the GO-PA membrane could effective remove the dyes and its rejection were above 98%.