水溶液介质中氯酚类有机污染物的生物修复研究
发布时间：2018-11-07 11:57
【摘要】：白腐菌降解污染物具有非专一性、高效性、广谱性等特点,在氯酚类难降解有机物的生物修复中有良好的应用前景。白腐菌和漆酶在工业废水处理和纸浆生物漂白等方面表现出很大的研究价值和应用潜力,然而漆酶的生产过程中普遍存在漆酶产量低、生产成本高等问题。本论文通过研究添加廉价天然底物和金属离子,优化产酶培养基,提高漆酶产量,并对各个影响因子进行优化,结合发酵动力学模型探讨白腐菌产酶规律。分别将白腐菌和漆酶用于氯酚类化合物废水中,研究白腐菌和漆酶对废水的生物修复机理。旨在为白腐菌和漆酶在废水处理领域的应用提供一定的理论依据与技术支持。本论文以糙皮侧耳(Pleurotus ostreatus)为研究对象,通过添加不同天然底物,对糙皮侧耳发酵产漆酶条件进行优化。结果显示,添加桔皮培养基优化效果最好,最高酶活由5U/mL提高为45U/mL,发酵时间比原来缩短了1/3。同时对其发酵动力学进行研究,得出A、B两组动力学模型,对比A(添加桔皮)、B(对照)两组发酵动力学模型,加入桔皮后,菌体的增殖能力和产漆酶能力都得到大幅度提高,菌体生长速率和产率系数也得到不同程度的提高。对白腐菌修复氯酚类废水的降解机理进行研究,研究发现:P.ostreatus对氯酚/苯酚类物质吸附能力顺序为:2,4,6-TCP2-CP苯酚PCP;不同氯酚加入方式并没有最终引起生物量发生很大变化,第5d加入2-CP和2,4,6-TCP组酶活分别是逐步加入2-CP和2,4,6-TCP组酶活的10倍和5倍,第5d集中加入氯酚后,三种氯酚去除率相比之前都得到不同程度提高,由此可以通过改变氯酚加入方式的方法来减小氯酚对漆酶酶活的抑制作用,同时可以提高氯酚去除率。研究P.ostreatus去除氯酚的作用分析,氯酚浓度介于10~30mg/L时,2-CP降解作用占绝大部分比例,吸附作用所占比例较小;TCP降解过程中,吸附作用和降解作用所占比例相当;相对于吸附作用来说,PCP降解作用占大部分比例,降解作用比例随着浓度增加有所减少。初步纯化获得粗酶,研究了粗酶的性质:最适反应温度为45℃,最适反应pH=3;粗酶降解氯酚过程中,可以通过增加漆酶浓度,利用缓冲溶液,加入介体ABTS(2,2-联氨-二(3-乙基苯并噻唑-6-磺酸)二铵盐),提高氯酚去除率,同时随着反应时间的延长,漆酶酶活逐渐降低;漆酶降解氯酚的动力学曲线符合一级反应动力学规律,并根据阿伦尼乌斯公式,计算得出漆酶催化2-CP,2,4,6-TCP和PCP三种氯酚反应的活化能依次为:26.52,33.52和48.19KJ/mol。
[Abstract]:The degradation of pollutants by white rot fungi has the characteristics of non-specificity, high efficiency and broad spectrum, so it has a good application prospect in the bioremediation of chlorophenol refractory organic compounds. White rot fungi and laccase have great research value and application potential in industrial wastewater treatment and pulp biological bleaching. However, laccase production is generally low in production process, high production cost and other problems. In this paper, by adding cheap natural substrates and metal ions, the enzyme production medium was optimized to increase the laccase yield, and various factors were optimized, and the enzyme production law of white rot fungi was discussed based on the fermentation kinetics model. White rot fungi and laccase were used in chlorophenol wastewater respectively to study the bioremediation mechanism of white rot fungi and laccase. The aim is to provide some theoretical basis and technical support for the application of white rot fungi and laccase in wastewater treatment. In this paper, the fermentation conditions of laccase from Pleurotus strigella (Pleurotus ostreatus) were optimized by adding different natural substrates. The results showed that the optimum culture medium of orange peel was the best, the highest enzyme activity was increased from 5U/mL to 45 U / mL, and the fermentation time was shortened by 1 / 3. At the same time, the fermentation kinetics was studied, and the two groups of dynamic models were obtained. Compared with A (orange peel), B (control), two groups of fermentation kinetics models were added, after the addition of orange peel, The ability of cell proliferation and laccase production were greatly improved, and the growth rate and yield coefficient were also improved to some extent. The degradation mechanism of chlorophenol wastewater remediated by white rot fungi was studied. It was found that the adsorption ability of P.ostreatus for chlorophenol / phenol was in the order of 2N 46-TCP2-CP phenol PCP;. Different chlorophenol addition methods did not result in a significant change in biomass. The enzyme activities in the 2-CP and 2H4 + 6-TCP groups on the 5th day were 10 times and 5 times higher than those in the gradually added 2-CP and 2H4 + 6-TCP groups, respectively, and were concentrated on the 5th day after chlorophenol was added. The three chlorophenol removal rates were improved in different degrees, so the inhibition of chlorophenol on laccase activity and the removal rate of chlorophenol could be reduced by changing the method of chlorophenol addition. The effect of P.ostreatus on the removal of chlorophenol was studied. When the concentration of chlorophenol was in the range of 10~30mg/L, the degradation of 2-CP accounted for the vast majority and the proportion of adsorption was small, and the proportion of adsorption and degradation was the same in the process of TCP degradation. Compared with adsorption, PCP degradation accounted for most of the proportion, and the degradation ratio decreased with the increase of concentration. The properties of crude enzyme were studied: the optimum reaction temperature was 45 鈩，
本文编号：2316294
[Abstract]:The degradation of pollutants by white rot fungi has the characteristics of non-specificity, high efficiency and broad spectrum, so it has a good application prospect in the bioremediation of chlorophenol refractory organic compounds. White rot fungi and laccase have great research value and application potential in industrial wastewater treatment and pulp biological bleaching. However, laccase production is generally low in production process, high production cost and other problems. In this paper, by adding cheap natural substrates and metal ions, the enzyme production medium was optimized to increase the laccase yield, and various factors were optimized, and the enzyme production law of white rot fungi was discussed based on the fermentation kinetics model. White rot fungi and laccase were used in chlorophenol wastewater respectively to study the bioremediation mechanism of white rot fungi and laccase. The aim is to provide some theoretical basis and technical support for the application of white rot fungi and laccase in wastewater treatment. In this paper, the fermentation conditions of laccase from Pleurotus strigella (Pleurotus ostreatus) were optimized by adding different natural substrates. The results showed that the optimum culture medium of orange peel was the best, the highest enzyme activity was increased from 5U/mL to 45 U / mL, and the fermentation time was shortened by 1 / 3. At the same time, the fermentation kinetics was studied, and the two groups of dynamic models were obtained. Compared with A (orange peel), B (control), two groups of fermentation kinetics models were added, after the addition of orange peel, The ability of cell proliferation and laccase production were greatly improved, and the growth rate and yield coefficient were also improved to some extent. The degradation mechanism of chlorophenol wastewater remediated by white rot fungi was studied. It was found that the adsorption ability of P.ostreatus for chlorophenol / phenol was in the order of 2N 46-TCP2-CP phenol PCP;. Different chlorophenol addition methods did not result in a significant change in biomass. The enzyme activities in the 2-CP and 2H4 + 6-TCP groups on the 5th day were 10 times and 5 times higher than those in the gradually added 2-CP and 2H4 + 6-TCP groups, respectively, and were concentrated on the 5th day after chlorophenol was added. The three chlorophenol removal rates were improved in different degrees, so the inhibition of chlorophenol on laccase activity and the removal rate of chlorophenol could be reduced by changing the method of chlorophenol addition. The effect of P.ostreatus on the removal of chlorophenol was studied. When the concentration of chlorophenol was in the range of 10~30mg/L, the degradation of 2-CP accounted for the vast majority and the proportion of adsorption was small, and the proportion of adsorption and degradation was the same in the process of TCP degradation. Compared with adsorption, PCP degradation accounted for most of the proportion, and the degradation ratio decreased with the increase of concentration. The properties of crude enzyme were studied: the optimum reaction temperature was 45 鈩，
本文编号：2316294
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