PVA/SA复合水凝胶溶胀及无机三氮离子传递性能  

Preparation of PVA/SA composite hydrogel and its diffusibility performance for NH_4^+,NO_2^-and NO_3^-

作　　者：赖子尼[1,2] 崔英德[3] 吴星祥[2] 

机构地区：[1]西北工业大学材料学院,陕西西安710072 [2]中国水产科学院珠江水产研究所,广东广州510380 [3]仲恺农业工程学院化学与化工系,广东广州510225

出　　处：《化工学报》2008年第12期3144-3149,共6页CIESC Journal

基　　金：国家自然科学基金项目(20376087);广东省自然科学基金项目(033307)~~

摘　　要：以聚乙烯醇(PVA)、海藻酸钠(SA)、活性炭、硼酸和氯化钙为原料,制备复合水凝胶微生物固定化载体材料,分析了离子在水凝胶膜中的扩散渗透机理,采用池膜法测定水凝胶的NH4+、NO2-、NO3-离子扩散性能。结果表明,在PVA、SA、活性炭含量分别为4%、2.0%及0.2%时,以5%的氯化钙的饱和硼酸溶液为交联剂,交联时间15min的条件下制备的固定化脱氮微生物载体传递性能最佳。复合水凝胶平衡溶胀度、扩散系数随PVA浓度升高而增大,随SA浓度升高溶胀度降低,离子扩散系数起初随SA浓度升高而升高,随后出现拐点。3种无机氮离子在水凝胶中的传递速率依次为NH4+>NO2->NO3-,遵从离子有效截面积小,传递速率大的规律。改变水凝胶制备条件、原料配比对NO2-、NH4+的渗透系数影响较大,而对NO3-影响较小。A copolymer hydrogel for immobilized microorganism carrier was synthesized by using sodium alginate （SA）, polyvinyl alcohol （PVA） and active carbon as start materials and calcium chloride and boric acid as crosslinker. The ionic diffusion mechanism was analyzed and the diffusibility of NH4^＋ , NO2ˉ and NO3ˉ was measured by the static penetration method. The result showed that the hydrogel prepared by crosslink 4% PVA, 2.0% sodium alginate and 0.2% active carbon with 5% calcium chloride and saturated boric acid as erosslinker for 15 rain possessed the highest ionic permeability. The degree of equilibrium swelling and ionic diffusion coefficient of the composite hydrogel increased with increasing concentration of PVA. The degree of equilibrium swelling decreased with increasing concentration of SA but the ionic diffusion coefficient first increased and then decreased with increasing SA concentration. The diffusion rate of the inorganic nitrogen-containing ion in the hydrogel decreased as fellows： NH4＋^, NO2ˉ NO3ˉ. The synthesis condition and the start materials ratio had a great impact on the diffusion coefficient of NO2ˉ and NH4^＋ , but a relatively small impact on that of NO3ˉ.

关 键 词：复合水凝胶 溶胀 离子渗透 无机三氮 池膜法 

分 类 号：TQ317.3[化学工程—高聚物工业]