珠线型载漆酶电纺纤维膜对水中菲的净化性能和机理

采用乳液静电纺丝技术制备珠线型载漆酶电纺纤维膜(以下简称酶膜),实现了漆酶在纤维珠泡中的原位包埋固定。与直线型相比,珠线型酶膜的载酶量提高了1倍,酶活性回收率达78.9%,且戊二醛交联可使酶膜储存和操作稳定性显著增加。将优化后所得酶膜用于水中典型多环芳烃菲的净化,结果表明:与游离漆酶相比,珠线型酶膜对污染物的降解率和去除率均显著增加,对0.01~2.00 mg/L的菲溶液吸附率超过80%,降解率超过72%;而且对pH、温度等环境变化的耐受性能明显增强,这主要归功于漆酶在珠泡中的集中固定和纤维珠泡外壳对漆酶的保护作用。此外,发光细菌毒性试验结果表明,经游离漆酶和珠线型酶膜处理后,不同浓度菲溶液的毒性均有所降低,但经酶膜处理后的菲溶液毒性降低更显著。

Purification performance and mechanism of phenanthrene in water by beads-in-string structural laccase-carrying electrospun fibrous membranes

The beads-in-string structural laccase-carrying electrospun fibrous membranes (LCEFMs) were prepared by emulsion electrospinning technology, and the laccase could be successfully encapsulated in the beads of electrospun fibers in situ. Compared with the linear LCEFMs, the laccase load of the beads-in-string structural LCEFMs was doubled, and the retained laccase activity reached 78.9%. Furthermore, the storage and operational stability of the beads-in-string structural LCEFMs were significantly increased after glutaraldehyde cross-linking. The optimized LCEFMs were used for the purification of typical polycyclic aromatic hydrocarbons in water. The result showed that compared with free laccase, the degradation and removal efficiencies of phenanthrene by the beads-in-string structural LCEFMs were obviously enhanced. For phenanthrene solution with concentration from 0.01 to 2.00 mg/L, the adsorption and degradation efficiency of the beads-in-string structural LCEFMs could reach over 80% and 72%, respectively. Furthermore, the tolerance of LCEFMs to the changes in environmental factors such as pH, temperature was also dramatically improved, which was attributed to the concentrated immobilization of laccase in the bead and the protective effect of the fibrous shell on laccase. In addition, the toxicity of the luminescent bacteria was detected for evaluating the toxicity of phenanthrene solution. The results showed that the toxicity of phenanthrene solution was reduced after treated by free laccase or the beads-in-string structural LCEFMs. By contrast, the beads-in-string structural LCEFMs could reduce more toxicity of phenanthrene solution with different concentrations than free laccase.