固定化微生物对酚类物质的降解性能研究
发布时间：2018-09-05 06:17
【摘要】：含酚废水是一种普遍存在并对人类生命安全危害严重的工业废水。因此，含酚废水的处理引起了人们高度重视，并逐步形成了以物理法、化学法、生物法为代表的三大处理技术。其中生物法中的固定化微生物法因微生物密度高且流失少、反应速度快、耐毒害能力强、微生物代谢产物容易分离、处理设备简单等特点得到广泛应用。 本论文采用以苯酚和对硝基苯酚为唯一碳源的无机盐培养基分别筛选出对苯酚和对硝基苯酚有良好降解能力的菌株FG-01和FG-02，经菌株鉴定后，用固定化材料钙基膨润土和羧甲基纤维素钠（CMC）将其分别固定，研究固定化微生物的降酚性能。主要研究内容如下： 1、菌株FG-01和菌株FG-02的16SrDNA序列同源性分析结果表明：菌株FG-01与菌株Bacillus pumilus (DQ907936，芽孢杆菌属)相似性100%，菌株FG-02与菌株Aeromicrobium erythreum (GU186112，气微菌属)相似性为84.3%。 2、研究了固定化微生物颗粒的制备条件，并对其结构进行了表征，同时进行了固定化微生物颗粒稳定性研究。正交实验结果表明：固定化微生物颗粒制备的最佳条件为AlCl3浓度为1%，钙基膨润土的含量为5%，，菌悬液的量为20%，交联时间为1h，钙基膨润土的粒径为100目，CMC含量为3%。最优条件下制得的固定化微生物颗粒对苯酚的降解率为93.22%（苯酚初始浓度为50mg/L），对对硝基苯酚的降解率为74.28%（对硝基苯酚初始浓度为10mg/L）。通过扫描电镜SEM对固定化颗粒结构进行表征，结果表明：材料内部的褶皱结构较多，钙基膨润土和CMC结合增大了材料内部的比表面积，非常有利于微生物在材料内部生长。通过探究固定化微生物颗粒的储存稳定性和重复利用性，结果表明：固定化微生物颗粒在4℃保存40d时，其苯酚降解率仍可达90%以上，其被连续使用了9批次时，苯酚降解率仍有88%以上。 3、研究了固定化单一微生物颗粒对苯酚和对硝基苯酚的降解性能。考察了颗粒投加量，初始浓度，温度，降解时间对酚类物质降解的影响。结果表明：固定化微生物颗粒降解酚类物质的最佳投加量为0.23g/mL，最佳温度为35℃。固定化FG-01颗粒耐苯酚的最高浓度为1000mg/L，而固定化FG-02颗粒耐对硝基苯酚的最高浓度仅为150mg/L。 4、对游离菌、CMC-钙基膨润土固定化颗粒、CMC-钙基膨润土固定化微生物颗粒、CMC固定化微生物颗粒的降酚性能进行对比研究，结果表明：各系统对酚类物质的降解效果为：CMC-钙基膨润土固定化微生物颗粒CMC-钙基膨润土固定化颗粒游离菌CMC固定化微生物颗粒，即复合载体共固定化微生物颗粒对酚类物质的降解率最高。 5、研究了外加碳源对固定化单一微生物降解酚类物质的影响，结果表明：当对硝基苯酚浓度50mg/L时，对固定化FG-01颗粒降解苯酚基本上没有影响，仅延长了降解平衡时间。当对硝基苯酚初始浓度50mg/L时，抑制作用逐渐明显，当对硝基苯酚初始浓度为100mg/L时，固定化FG-01颗粒降解苯酚的降解率仅为28.95%。同时固定化FG-01颗粒内部的微生物FG-01也可以以对硝基苯酚为共代谢碳源，当对硝基苯酚浓度为30mg/L时，对对硝基苯酚的同时降解率达到最大，为55.45%。当对硝基苯酚浓度逐渐增大时，降解率逐渐下降；固定化FG-02颗粒的微生物FG-02可以以苯酚和对硝基苯酚作为共代谢碳源，而对硝基苯酚的毒性较对苯酚的大，并且对硝基苯酚的降解途径较苯酚的复杂，故FG-02对苯酚的利用率较对硝基苯酚的利用率大。 6、研究了固定化复合微生物对混合废水降解的影响，结果表明：复合载体内部包埋的微生物FG-01/FG-02比例为4:2时，固定化复合微生物颗粒对苯酚和对硝基苯酚均有较高的降解率。
[Abstract]:Phenolic wastewater is a kind of industrial wastewater which is ubiquitous and harmful to human life. Therefore, the treatment of phenolic wastewater has attracted great attention and three major treatment technologies have been gradually formed, including physical, chemical and biological methods. It has been widely used for its rapid reaction, high toxicity resistance, easy separation of microbial metabolites and simple treatment equipment.
In this paper, the strains FG-01 and FG-02 with good degradability of p-nitrophenol and p-nitrophenol were screened out by using inorganic salt medium with phenol and p-nitrophenol as the sole carbon source. After identification of the strains, they were immobilized with calcium-based bentonite and sodium carboxymethylcellulose (CMC) respectively to study the phenol-reducing effect of immobilized microorganisms. The main research contents are as follows:
1. The 16S rDNA sequence homology analysis of strain FG-01 and FG-02 showed that the similarity between strain FG-01 and Bacillus pumilus (DQ907936, Bacillus) was 100%, and that between strain FG-02 and Aeromicrobium erythreum (GU186112, Aeromicrobium) was 84.3%.
2. The preparation conditions of immobilized microbial particles were studied, and their structures were characterized. The stability of immobilized microbial particles was also studied. The results of orthogonal experiment showed that the optimum conditions for the preparation of immobilized microbial particles were 1% AlCl3, 5% Ca-bentonite, 20% suspension and 1 h crosslinking time. The particle size of Ca-bentonite was 100 mesh and the CMC content was 3%. Under the optimum conditions, the immobilized microbial particles could degrade phenol 93.22% (the initial concentration of phenol was 50mg/L) and p-nitrophenol 74.28% (the initial concentration of p-nitrophenol was 10mg/L). The structure of the immobilized particles was characterized by SEM. The results show that there are many folds in the material, and the combination of calcium-based bentonite and CMC enlarges the specific surface area of the material, which is beneficial to the growth of microorganisms in the material. The rate of hydrolysis is still more than 90%. When it is used in 9 batches, the phenol degradation rate is still over 88%.
3. The degradation of phenol and p-nitrophenol by immobilized single microbial particles was studied. The effects of dosage, initial concentration, temperature and degradation time on the degradation of phenols were investigated. The results showed that the optimum dosage of immobilized microbial particles was 0.23g/mL, and the optimum temperature was 35 C. FG-01 particles were immobilized. The highest concentration of phenol-resistant granules was 1000 mg/L, while the highest concentration of p-nitrophenol-resistant immobilized FG-02 granules was only 150 mg/L.
4. The phenol-reducing properties of free bacteria, CMC-Ca-bentonite immobilized particles, CMC-Ca-bentonite immobilized microbial particles and CMC immobilized microbial particles were compared. The results showed that the phenolic substances were degraded by each system as follows: CMC-Ca-bentonite immobilized microbial particles CMC-Ca-bentonite immobilized particles were free. Bacterial CMC immobilized microbial particles, i.e. composite carrier co-immobilized microbial particles, had the highest degradation rate of phenolic substances.
5. The effect of carbon source on the degradation of phenolic substances by immobilized single microorganism was studied. The results showed that when the concentration of p-nitrophenol was 50mg/L, the degradation of phenol by immobilized FG-01 particles was almost unchanged, but the equilibrium time was prolonged. At the initial concentration of 100mg/L, the degradation rate of phenol by immobilized FG-01 particles was only 28.95%. At the same time, the microorganism FG-01 in the immobilized FG-01 particles could also use p-nitrophenol as co-metabolic carbon source. When the concentration of p-nitrophenol was 30mg/L, the degradation rate of p-nitrophenol was the highest, which was 55.45%. The degradation rate of FG-02 decreased gradually with the increase of FG-02 particles. The immobilized FG-02 particles could use phenol and p-nitrophenol as co-metabolic carbon sources, and the toxicity of FG-02 to nitrophenol was greater than that to p-phenol, and the degradation pathway of FG-02 to nitrophenol was more complex than that to phenol, so the utilization rate of FG-02 to phenol was higher than that to p-nitrophenol.
6. The effect of immobilized composite microorganism on the degradation of mixed wastewater was studied. The results showed that the immobilized composite microorganism particles had higher degradation rate of phenol and p-nitrophenol when the ratio of FG-01/FG-02 was 4:2.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172;X703
[Abstract]:Phenolic wastewater is a kind of industrial wastewater which is ubiquitous and harmful to human life. Therefore, the treatment of phenolic wastewater has attracted great attention and three major treatment technologies have been gradually formed, including physical, chemical and biological methods. It has been widely used for its rapid reaction, high toxicity resistance, easy separation of microbial metabolites and simple treatment equipment.
In this paper, the strains FG-01 and FG-02 with good degradability of p-nitrophenol and p-nitrophenol were screened out by using inorganic salt medium with phenol and p-nitrophenol as the sole carbon source. After identification of the strains, they were immobilized with calcium-based bentonite and sodium carboxymethylcellulose (CMC) respectively to study the phenol-reducing effect of immobilized microorganisms. The main research contents are as follows:
1. The 16S rDNA sequence homology analysis of strain FG-01 and FG-02 showed that the similarity between strain FG-01 and Bacillus pumilus (DQ907936, Bacillus) was 100%, and that between strain FG-02 and Aeromicrobium erythreum (GU186112, Aeromicrobium) was 84.3%.
2. The preparation conditions of immobilized microbial particles were studied, and their structures were characterized. The stability of immobilized microbial particles was also studied. The results of orthogonal experiment showed that the optimum conditions for the preparation of immobilized microbial particles were 1% AlCl3, 5% Ca-bentonite, 20% suspension and 1 h crosslinking time. The particle size of Ca-bentonite was 100 mesh and the CMC content was 3%. Under the optimum conditions, the immobilized microbial particles could degrade phenol 93.22% (the initial concentration of phenol was 50mg/L) and p-nitrophenol 74.28% (the initial concentration of p-nitrophenol was 10mg/L). The structure of the immobilized particles was characterized by SEM. The results show that there are many folds in the material, and the combination of calcium-based bentonite and CMC enlarges the specific surface area of the material, which is beneficial to the growth of microorganisms in the material. The rate of hydrolysis is still more than 90%. When it is used in 9 batches, the phenol degradation rate is still over 88%.
3. The degradation of phenol and p-nitrophenol by immobilized single microbial particles was studied. The effects of dosage, initial concentration, temperature and degradation time on the degradation of phenols were investigated. The results showed that the optimum dosage of immobilized microbial particles was 0.23g/mL, and the optimum temperature was 35 C. FG-01 particles were immobilized. The highest concentration of phenol-resistant granules was 1000 mg/L, while the highest concentration of p-nitrophenol-resistant immobilized FG-02 granules was only 150 mg/L.
4. The phenol-reducing properties of free bacteria, CMC-Ca-bentonite immobilized particles, CMC-Ca-bentonite immobilized microbial particles and CMC immobilized microbial particles were compared. The results showed that the phenolic substances were degraded by each system as follows: CMC-Ca-bentonite immobilized microbial particles CMC-Ca-bentonite immobilized particles were free. Bacterial CMC immobilized microbial particles, i.e. composite carrier co-immobilized microbial particles, had the highest degradation rate of phenolic substances.
5. The effect of carbon source on the degradation of phenolic substances by immobilized single microorganism was studied. The results showed that when the concentration of p-nitrophenol was 50mg/L, the degradation of phenol by immobilized FG-01 particles was almost unchanged, but the equilibrium time was prolonged. At the initial concentration of 100mg/L, the degradation rate of phenol by immobilized FG-01 particles was only 28.95%. At the same time, the microorganism FG-01 in the immobilized FG-01 particles could also use p-nitrophenol as co-metabolic carbon source. When the concentration of p-nitrophenol was 30mg/L, the degradation rate of p-nitrophenol was the highest, which was 55.45%. The degradation rate of FG-02 decreased gradually with the increase of FG-02 particles. The immobilized FG-02 particles could use phenol and p-nitrophenol as co-metabolic carbon sources, and the toxicity of FG-02 to nitrophenol was greater than that to p-phenol, and the degradation pathway of FG-02 to nitrophenol was more complex than that to phenol, so the utilization rate of FG-02 to phenol was higher than that to p-nitrophenol.
6. The effect of immobilized composite microorganism on the degradation of mixed wastewater was studied. The results showed that the immobilized composite microorganism particles had higher degradation rate of phenol and p-nitrophenol when the ratio of FG-01/FG-02 was 4:2.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172;X703
【参考文献】
相关期刊论文 前10条
1 吴勇民;李甫;黄咸雨;胡和兵;;含酚废水处理新技术及其发展前景[J];环境科学与管理;2007年03期
2 肖亦;钟飞;潘献晓;;固定化微生物技术在废水处理中的应用研究进展[J];环境科学与管理;2009年06期
3 左鹏;于少明;杨杰茹;章t熱
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