生物吸附与微生物降解对多溴联苯醚污染土壤和水体的修复研究

发布时间：2018-07-04 11:11

本文选题：BDE-3 + 生物碳　；参考：《浙江农林大学》2015年硕士论文

【摘要】：多溴联苯醚(Poly brominated diphenyl ethers,PBDEs)作为阻燃剂被广泛地使用,其对人类的各器官,神经系统和免疫系统的危害已经逐渐被认知。因此,PBDEs在生产、使用及销毁过程中对水体和土壤的污染现状和修复方法也备受关注。本研究以4-溴联苯醚(BDE-3)作为降解对象,详细论述了利用降解菌株Sphingomonas sp.DZ3与生物材料相结合对污染水体和土壤进行修复的可行性,同时深入研究了生物材料对污染物的吸附机理以及微生物与生物材料相结合的增益效应。主要的试验结果如下：(1)对受BDE-3污染的水体进行修复时发现,生物碳对BDE-3有较好的吸附效应,最大吸附量为50.23 mg·g-1。Freundlich等温吸附方程和准一级动力学方程可以良好描述吸附过程。利用神经网络模型(ANN)对影响吸附过程的各因素建模分析,发现BDE-3初始浓度对吸附过程的影响最大,相对重要性为37.23%,温度次之(为29.69%),其余依次为时间(24.63%)和pH(8.45%)。固定化Sphingomonas sp.DZ3与游离菌株相比,降解率提高了51%。(2)为原位修复受BDE-3污染的土壤,制得了海藻酸钠-生物碳微球菌剂,通过优化,2%海藻酸钠为最佳制备浓度。研究微球纯材料对土壤中BDE-3的吸附特性发现,Lagergren准一级动力学方程和Elovich方程可以良好描述吸附过程。微球菌剂可对BDE-3浓度为1000mg·kg-1的土壤进行修复,30 d可以完全完成降解。利用Monod降解动力学方程对降解过程进行拟合,得到降解动力学方程为：(3)在利用生物泥浆对BDE-3污染的土壤进行修复时,对生物泥浆法的运行条件进行了优化并建立了降解动力学模型。结果表明,生物泥浆的最佳水土比例为2：1,最适微生物接种量为5%,土壤中污染物极限浓度为3000mg·kg-1,Tween80的最佳添加量为0.5%。利用ANN进行分析发现,影响污染修复的4个因素的相对重要性依次为：BDE-3初始浓度(32.75%),接种量(25.57%),表面活性剂(23.33%)和水土比(18.32%)。降解动力学方程为：
[Abstract]:Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants, and their harm to human organs, nervous system and immune system has been gradually recognized. Therefore, the pollution status and remediation methods of PBDEs to water and soil in the process of production, use and destruction are also concerned. In this study, 4-brominated diphenyl ether (BDE-3) was used as the degradation object, and the feasibility of remediation of polluted water and soil by combining degradation strain Sphingomonas sp. DZ3 with biomaterials was discussed in detail. At the same time, the adsorption mechanism of pollutants by biomaterials and the gain effect of the combination of microorganisms and biomaterials were studied. The main results are as follows: (1) when the BDE-3 polluted water was remedied, it was found that the adsorption of BDE-3 was better by biological carbon, and the maximum adsorption amount was 50.23 mg g-1.Freundlich isothermal adsorption equation and quasi-first-order kinetic equation could describe the adsorption process well. The neural network model (Ann) was used to model and analyze the factors affecting the adsorption process. It was found that the initial concentration of BDE-3 had the greatest influence on the adsorption process, the relative importance was 37.23.3%, the second was temperature (29.69%), the rest was time (24.63%) and pH (8.45%). The degradation rate of immobilized Sphingomonas sp. DZ3 was increased by 51% compared with the free strain. (2) Sodium alginate and biological carbon microspheres were prepared by in situ remediation of BDE-3 contaminated soil. The optimum concentration of sodium alginate was optimized as 2% sodium alginate. The adsorption characteristics of BDE-3 in soil by microsphere pure materials were studied. It was found that Lagergren quasi first order kinetic equation and Elovich equation could describe the adsorption process well. The soil with BDE-3 concentration of 1000mg kg-1 could be completely degraded after 30 days of soil remediation with microspheres. Monod degradation kinetics equation was used to fit the degradation process, and the degradation kinetics equation was obtained as follows: (3) when using biological mud to remediate BDE-3 contaminated soil, The operating conditions of the biological slurry method were optimized and the degradation kinetics model was established. The results showed that the optimum soil and water ratio was 2: 1, the optimum inoculation amount was 5, the limit concentration of pollutants in the soil was 3000mg kg-1 Tween80, and the optimum addition amount was 0.5%. The results of Ann analysis showed that the relative importance of the four factors affecting the remediation of pollution was: initial concentration of BDE-3 (32.75%), inoculation amount (25.57%), surfactant (23.33%) and water / soil ratio (18.32%). The kinetic equation of degradation is:
【学位授予单位】：浙江农林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172;X53;X52

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