【作者】 陈军；

【导师】 华兆哲；

【作者基本信息】 江南大学 ， 环境工程， 2006， 硕士

【摘要】 过氧化氢酶是一种重要的抗氧化酶,对羟基自由基、超氧阴离子等自由基具有较好的清除能力。本论文以壳聚糖固定化过氧化氢酶提高过氧化氢酶的稳定性及其在卷烟滤嘴生产中添加的可操作性,从而达到以过氧化氢酶清除卷烟烟气中自由基的目的。主要的研究内容与结果如下:1.确定了壳聚糖固定化过氧化氢酶的固定化方案,对固定化过程进行了优化。固定化的最优条件为:酶液(过氧化氢酶酶活2×104CIU/ml):3%壳聚糖溶液:交联剂=6: 20: 100(v: v: v),乙二醛浓度6%(w/v),吸附时间0.5h,交联时间2.5h。2.对固定化过氧化氢酶的性质进行了初步的研究:红外分析结果说明过氧化氢酶完成了交联反应;固定化过氧化氢酶的米氏常数Km从游离酶的30.3mmol/L增加到61.7mmol/L,固定化酶对过氧化氢的亲和性明显下降;最适pH值为7.0,且在5-9范围均保持较高的酶活;其热稳定性和贮藏稳定性均得到了提高。3.以紫外光-TiO2催化自由基产生体系初步考察了过氧化氢酶清除自由基的能力。活性过氧化氢酶对紫外光-TiO2催化体系产生的自由基几乎能完全清除,而热灭活的过氧化氢酶对此体系的自由基几乎不能清除。说明只有具有活性的过氧化氢酶具有清除自由基的能力。4.固定化过氧化氢酶对邻苯三酚体系产生的自由基同样有清除作用,9ml 0.2mmol/L邻苯三酚溶液中,当加入固定化过氧化氢酶0.08g时,对其自氧化达到50%抑制。5.以壳聚糖固定化过氧化氢酶为一种卷烟滤嘴添加剂,研究其去除主流烟气中自由基的效果。当滤嘴中固定化过氧化氢酶添加量分别是10、30、50mg/支时,气相自由基分别减少了6.5%、9.9%和15.1%;固相自由基分别减少2.3%、21.9%和40.8%。6.采用机械干法添加的方式可以提高固定化过氧化氢酶对自由基的清除效率。10mg/支的机械干法添加的清除自由基效果为:气相自由基下降35%,固相自由基下降22.4%。7.考察了壳聚糖固定化过氧化氢酶对卷烟中其他有害物质的去除效果,包括烟碱、烟气总粒相物(TPM)、焦油和烟草特有亚硝胺。壳聚糖固定化过氧化氢酶能明显的减少烟气中总粒相物的量,在添加40mg/支时,TPM的量小于10mg/支,降幅超过60%;焦油3.5mg/支,下降77.8%;添加量为30mg/支时,烟碱从0.94mg/支下降到0.68mg/支,下降了28%;TSNA由0.37μg/支下降为0.27μg/支,下降超过25%。更多还原

【Abstract】 The preparation and application of catalase powder immobilized by chitosan used as a kind of cigarette filter additive was investigated in the present paper. The results showed that:1. Catalase was immobilized on chitosan with glyoxal by cross-linking reaction. The conditions for immobilization were optimized as follows: 3% chitosan 20ml, cross-linking reagent 100ml, enzyme 6ml, the concentration of glyoxal 6%, adsorption time 2.5h, cross-linking reaction time 0.5h. The activity yield of the immobilized catalase was 42.9% of the original.2. The characteristics of the immobilized catalase such as the optimal pH, thermal stability, and storage stability were assessed. The Km, an important kinetic parameter of enzyme, was obtained as 61.7 mmol/L with Lineweaver-bulk method. Immobilized catalase has the same optimum pH (7.0) as the free enzyme, and the pH profile of it was broader with respect to the free enzyme.3. The study showed that the activity catalase can scavenge free radical in Water-UV-TiO2 system, while the catalase denaturalized by heat nearly can’t, which means that only activity catalase can scavenge free radicals.4. Moreover, the immobilized catalase was found to be able to remove superoxide anion free radical (SAFR) produced in pyrogallic acid system.5. It was found that immobilized catalse added in cigarette filter cleared away free radicals in mainstream smoke. The free radicals in gas phase were decreased 6.5%, 9.9% and 15.1%, and that in tar decreased 2.3%, 21.9% and 40.8% as the quantity of immobilized catalase appended was 10, 30 and 50mg/cig. The results showed that free radicals in mainstream smoke were reduced significantly with the increase of immobilized catalase added.6. It was observed that immobilized catalse added in cigarette filter can reduce other toxicants in mainstream smoke. TPM, tar, nicotine and TSNA, was reduced 60%, 50%, 28% and 25%, respectively.更多还原