弱酸性条件下氧化剂诱导多巴胺改性疏水性PVDF膜应用于MABR技术

Oxidant Induces Dopamine-Modified Hydrophobic PVDF Hollow Fiber Membrane Under Weak Acid Conditions to be Applied to MABR Technology

论文针对膜曝气生物膜反应器(Membrane Aeration Biofilm Reactor,MABR)研究中疏水性微孔膜泡点压力低、氧传质性能不佳等以及多巴胺改性复合膜改性过程中改性时间长、复合层稳定性能欠佳等问题,采用简便的单步氧化法,在弱酸性环境中(pH值=5.0)选用高碘酸钠诱导氧化多巴胺(Dopamine,DOPA)对疏水性PVDF中空纤维微孔膜进行表面涂覆改性,并采用响应曲面法优化了涂覆表面改性条件,在1.48 h、1.014 g/L和39℃下实现了多个响应变量的单一最佳点。在最佳涂覆条件下获得的PDA-coated PVDF改性膜氧传质性能由原膜0.77×10^(-2)min^(-1)提升至1.68×10^(-2)min^(-1),为原膜的2.18倍。进一步的FSEM、FTIR、XPS分析表明PDA聚合物成功涂覆在膜表面,AFM结果表明最佳改性膜表面粗糙度增加,改性膜其它基本性能都显著提升。

In this paper,the problems such as low bubble pressure and poor oxygen mass transfer performance of hydrophobic microporous Membrane in Membrane Aeration Biofilm Reactor(MABR),long modification time and poor stability of composite Membrane in the process of dopamine-modified composite Membrane modification are discussed.Using a simple one-step oxidation method,in a weakly acidic environment(pH=5.0),sodium periodate is used to induce the oxidation of dopamine(DOPA)to modify the surface of the hydrophobic PVDF hollow fiber microporous membrane.The coating surface modification conditions were optimized by response surface method,and a single optimal point for multiple response variables was achieved at1.48 h,1.014 g/L and 39℃.The oxygen mass transfer performance of the modified PDA-coated PVDF membrane obtained under the optimal coating conditions was increased from 0.77×10^(-2)min^(-1) to 1.68×10^(-2)min^(-1),which was 2.18 times that of the original membrane.Further FSEM,FTIR,XPS analysis showed that the PDA polymer was successfully coated on the surface of the film,and the AFM results showed that the surface roughness of the best modified film was increased,and other basic properties of the modified film were significantly improved.