功能菌剂复配对邻苯二甲酸二丁酯污染土壤的修复研究

发布时间：2018-11-01 18:46

【摘要】：邻苯二甲酸二丁酯(DBP)作为一种增塑剂,被广泛的应用于塑料制品中。近年来,我国农膜的使用量不断增加,由于塑料农膜的稳定性差,极易导致PAEs从塑料薄膜中释放。因此,越来越多的DBP进入到周边土壤中,导致农业用地污染。另外,由于化肥、污灌等的不当使用,也会使土壤中DBP的含量有所增加。受DBP污染土壤的影响,导致种植的作物对DBP的积累,进而通过食物链进入到人体中,对人体内分泌、神经系统等产生危害,因此土壤中DBP污染的防治刻不容缓。目前相关的研究主要集中在DBP降解菌的筛选及特性机理研究,而DBP降解菌功能菌群制剂的研发等相关方面的研究较少。微生物修复技术具有高效、成本低、无二次污染、操作简便且处理效果好等优点。本试验旨在研发一种高效且协同修复效果良好的功能菌剂,在修复DBP污染土壤的同时,又能够对污染土壤肥力进行改良。通过盆栽试验,考察修复菌剂对小白菜生长的影响,进一步确定功能菌剂修复DBP污染土壤效果及其对土壤肥力改良效果,考察功能菌剂对土壤生态安全的影响,探讨DBP微生物修复技术的实际应用价值,为PAEs污染土壤的修复提供科学依据及技术支持,为土壤有机污染的生物修复提供参考。主要研究结果如下:从土壤中筛选分离得到3株植物促生菌(解磷菌P6、解钾菌K5、固氮菌N1),经鉴定解磷菌为鞘脂菌(Sphingobium yanoikuyae)、解钾菌为胶质芽孢杆菌(Paenibacillus mucilaginosus)、固氮菌为产酸克雷伯氏菌(Enterobacter aerogenes)。对其各自活力进行测定,最终确定P6的解磷能力为28.44 mg/L,K5解钾量为22.61μg/m L,N1菌株的固氮能力为14.56 mg/L。将3株促生菌与DBP降解菌(实验室前期筛选所得,为假单胞菌(Pseudomonas sp.),并命名DNB-S1)进行平板划线以及摇瓶试验,结果表明各菌株之间不存在拮抗反应,并且不会影响各自的活力。利用发酵培养基混合菌群发酵48 h,平板计数法得到固氮菌N1个数为5.3×108 cfu/m L,解磷菌P6个数为4.0×109 cfu/m L,解钾菌K5个数为5.0×109 cfu/m L,DBP降解菌DNB-S1个数为7.6×109 cfu/m L。经发酵的各菌株数量均在108 cfu/m L以上,发酵效果良好。以凹凸棒土、高岭土、腐殖酸作为载体,制备功能菌剂,常温保存备用。对菌剂内活菌数测定发现,室内常温保35 d时,四种细菌的活细胞数量还可以保持较高的活性,保存效果良好。功能菌剂中降解菌和促生菌配比优化试验表明,通过综合考察各处理组对于污染土壤中35 d的DBP降解率、土壤肥力改良情况(速效氮、速效磷、速效钾)以及对土壤中微生物多样性的影响情况,最终确定功能菌剂中降解菌与促生菌的配比为1:1(g:g)的时候,为最佳的配比方式。采用温室盆栽试验检验功能菌剂修复DBP污染土壤(20 mg/kg)效果,通过对经济作物小白菜生理指标和品质、土壤酶活性以及土壤肥力改良的效果表明:在小白菜生长过程中,添加功能菌剂的处理组叶绿素的含量显著高于污染处理组,MDA含量也较污染处理低,菌剂的加入,明显缓解了DBP对小白菜的毒害作用;收获期时小白菜体内干物质积累量明显高于对照,可溶性蛋白含量以及维生素C含量较污染处理组分别提升了24.93%、13.67%,提高了小白菜的品质。在修复过程中功能菌剂对土壤脲酶、蔗糖酶活性起到了激活作用,而对过氧化氢酶活性不会产生很大的影响;土壤中速效氮、速效磷及速效钾含量较对照分别提高了11.52%、11.01%、9.19%。
[Abstract]:Dibutyl phthalate (DBP) is widely used in plastic products as a plasticizer. In recent years, the use of agricultural film in our country has been increasing. Because of poor stability of plastic agricultural film, PAEs can easily be released from plastic films. Therefore, more and more DBP enters into the surrounding soil, which leads to the pollution of agricultural land. In addition, due to improper use of chemical fertilizer, sewage irrigation and the like, the content of DBP in soil can be increased. Due to the influence of DBP polluted soil, the accumulation of DBP in planted crops is caused, and the damage to endocrine and nervous system of human body is caused by the food chain entering into human body, so the prevention and cure of DBP pollution in soil is urgent. At present, the research on the screening and characterization mechanism of DBP-degrading bacteria is mainly focused on the research of the related aspects such as the research and development of DBP-degrading bacteria group preparation. The microbial remediation technology has the advantages of high efficiency, low cost, no secondary pollution, simple and convenient operation, good treatment effect and the like. The aim of this experiment is to develop a kind of functional microbial agent with high efficiency and good synergistic effect, which can improve the soil fertility while repairing DBP polluted soil. The effects of remediation agent on the growth of Chinese cabbage were studied by pot experiment, and the effect of functional microbial inoculum on soil fertility was further determined. The effect of functional agent on soil ecological safety was studied, and the practical application value of DBP microbial repair technology was discussed. provides scientific basis and technical support for remediation of PAEs polluted soil, and provides a reference for bioremediation of contaminated soil. The main results are as follows: 3 plant growth-promoting bacteria (P. P. P. 6, K _ 5, N1N1) were screened and isolated from the soil, and the Bacillus mucilaginosus was identified as Bacillus mucilaginosus and Enterobacter aerogenes. The nitrogen fixation capacity of NP1 was 14.56 mg/ L, and the nitrogen fixation capacity of N1 strain was 14.56 mg/ L. 3 strains of growth promoting bacteria and DBP degrading bacteria were screened for Pseudomonas sp. in the early stage of the laboratory. (2) and named DNB-S1 for plate marking and shaking flask test, and the results showed that there was no antagonistic reaction between the strains, and the activity was not affected. The fermentation medium was used to mix the bacteria group to ferment for 48h, and the number of NN1 in the plate counting method was 5. 3, 108 cfu/ m L, the number of P-solubilizing bacteria P6 was 4. 0-109 cfu/ m L, and the number of KK5 was 5. 0-109 cfu/ m L. The number of DBP-degrading bacteria DNB-S1 was 7. 6-109 cfu/ m L. The number of strains tested was above 108cfu/ m L and the fermentation effect was good. taking attapulgite, kaolin and humic acid as a carrier, preparing a functional microbial inoculum, and keeping standby at normal temperature. It was found that the living cells of four kinds of bacteria could keep higher activity at normal temperature for 35 days, and the preservation effect was good. The results showed that the degradation rate of DBP and soil fertility (quick-acting nitrogen, quick-acting phosphorus, available potassium) and the influence on microbial diversity in soil were investigated by comprehensive investigation of the degradation rate of DBP and soil fertility (available nitrogen, available phosphorus, available potassium) in the contaminated soil. finally, when the ratio of the degrading bacteria and the growth promoting bacteria in the functional microbial inoculum is 1 to 1 (g: g), the optimal matching mode is provided. The effects of functional microbial inoculum on the recovery of DBP contaminated soil (20 mg/ kg) were tested by pot pot experiment. The effects of physiological index and quality, soil enzyme activity and soil fertility on the physiological indexes and quality, soil enzyme activity and soil fertility of the young Chinese cabbage showed that during the growth of Chinese cabbage, the content of chlorophyll in the treatment group added with the functional microbial inoculum is obviously higher than that of the pollution treatment group, the content of MDA is lower than that of the pollution treatment group, the addition of the microbial inoculum obviously relieves the toxic effect of the DBP on the Chinese cabbage, the accumulation amount of dry matter in the Chinese cabbage is obviously higher than that of the control during the period of the treatment period, The soluble protein content and vitamin C content were increased by 24.93% and 13.67% respectively, and the quality of Chinese cabbage was improved. in that soil, the activity of the functional microbial agent on the soil, the activity of the sucrose enzyme play an active role, and the activity of the catalase doe not greatly affect the activity of the catalase; the quick-acting nitrogen, the quick-acting phosphorus and the quick-acting potassium content in the soil are respectively increased by 11.52 percent, 11.01 percent and 9.19 percent respectively.
【学位授予单位】：东北农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X53

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