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1.
低温条件下,从东北制药总厂的曝气池与氯霉素生产废水集水池污泥中分离、筛选得到6株以硝基苯为唯一碳源的降解菌,对6株菌进行降解能力研究得知,菌株cc-2为低温高效硝基苯降解菌。经形态特征和生理生化特征分析,初步鉴定属于不动杆菌属(Acinetobacter sp.)。菌株cc-2降解性能研究结果表明:菌株最佳条件为生长温度15℃、培养基pH值为7、摇床转速为140 r/min。最佳降解条件下,当硝基苯初始浓度为200 mg/L时菌株48h降解率达66.84%。外加葡萄糖和乙酸钠促进了菌株cc-2对硝基苯的生物降解,降解率分别为80.44%和78.57%,该菌株的生长降解性能研究为低温环境中硝基苯的修复提供了技术支撑。  相似文献   

2.
一株中度耐盐硝基苯降解菌的鉴定及降解特性   总被引:1,自引:0,他引:1       下载免费PDF全文
在高盐度(1%NaCl)条件下,从某制药厂曝气池的活性污泥中驯化、分离得到1株以硝基苯为唯一碳源的高效降解菌株N18,并通过菌体形态、生理生化反应特性、全细胞脂肪酸组分分析及16SrRNA基因测序分析对其进行初步鉴定.结果表明,菌株N18为蜡样芽胞杆菌(Bacilluscereus).该菌株利用硝基苯生长的最佳条件为接种量10%、生长温度30℃、pH=7.外加葡萄糖或乙酸钠可使硝基苯降解率分别由72.70%提高到82.62%和79.25%(硝基苯初始浓度为200mg.L-1,72h).在盐度为1%~3%时,硝基苯的降解情况基本不变,甚至在盐度为10%时仍能降解硝基苯,说明菌株N18为中度耐盐细菌.当150mg.L-1的苯酚或75mg.L-1的苯胺与200mg.L-1的硝基苯共存时,菌株仍能有效降解硝基苯.菌株对硝基苯的最大耐受浓度为400mg.L-1.  相似文献   

3.
嗜盐拟香味菌Y6降解硝基苯的特性研究   总被引:2,自引:1,他引:1       下载免费PDF全文
厉阗  钱坤  肖伟  王进军  邓新平 《环境科学》2013,34(2):753-759
研究拟香味菌Y6(Myroides odoratimimus strain)高盐条件下降解硝基苯的特性,拟解决高盐工业废水中硝基苯难降解问题.利用高效液相色谱测定硝基苯含量,分析高盐条件下温度、pH、硝基苯初始浓度、接种量、共代谢物等因素对菌Y6降解硝基苯特性的影响.结果表明,降解最佳条件为:pH值6,温度28℃,接种量D600=1,NaCl质量分数7%.在最佳降解条件下,菌株168 h内对100 mg·L-1和200 mg·L-1硝基苯降解率分别达到97.5%和65.7%.添加葡萄糖、淀粉和丙三醇对硝基苯降解均有促进作用,加入800 mg·L-1葡萄糖,其降解率达到93.3%(168 h,200 mg·L-1硝基苯).菌株Y6可用于硝基苯高盐工业废水的生物修复,这是首次报道耐盐拟香味菌降解硝基苯.  相似文献   

4.
菌株Ochrobactrum sp. CH10是从北京元大都城垣遗址处的人工湿地筛选到的高效苯酚降解菌.以苯酚为唯一碳源和能源对其进行了生长和苯酚降解特性的研究.该菌生长和降解苯酚的适宜条件为30℃、初始pH 7.0、接种量为5%.在该条件下,初始苯酚浓度为400 mg·L-1,24 h时苯酚完全被降解;初始苯酚浓度为900 mg·L-1时,44 h的降解率为92.3%;初始苯酚浓度为1 000 mg·L-1,48 h时的降解率为82.2%.对该菌株苯酚降解动力学过程进行模拟,符合基质抑制型的Haldane模型,各参数分别为:υmax(最大比降解速率)0.126 h-1,KS(半饱和常数)23.53 mg·L-1,KI(抑制常数)806.1 mg·L-1.该菌在苯酚中的生长动力学符合Andrews模型,表现出与苯酚降解相似的趋势.该菌为目前所发现的Ochrobactrum菌属中苯酚降解能力最强的菌株.该菌株在高效处理含酚废水方面具有广阔的应用前景.  相似文献   

5.
HP-β-CD对不动杆菌降解高浓度硝基苯的影响   总被引:7,自引:1,他引:7  
研究了在不动杆菌降解高浓度硝基苯的过程中添加羟丙基-β-环糊精(HP-β-CD)对细菌生长、硝基苯的去除及中间产物的转化的影响.利用乙酸酐直接将硝基苯的降解样品酰基化,通过GC-MS分析定性出降解中间产物2 氨基苯酚.在适宜降解菌生长的400mg·L-1硝基苯初始浓度下,加入250和500mg·L-1HP-β-CD对生物量和硝基苯的降解基本无影响;当硝基苯初始浓度约为850mg·L-1时,加入HP-β-CD(>2000mg·L-1)显著促进了细菌的生长、硝基苯的降解和2-氨基苯酚的生物转化,并且促进程度与加入量成正比.这种促进主要是因为HP-β-CD的空腔对硝基苯和2-氨基苯酚的包合产生了脱毒的效果.当HP-β-CD的加入浓度分别为0,2000,4000mg·L-1时,降解菌对850mg·L-1硝基苯的降解都遵循一级反应动力学,降解速率常数由0 0077h-1分别增加到0 0089和0 0161h-1,当HP-β-CD的加入浓度为8000mg·L-1时,降解菌对850mg·L-1硝基苯的降解遵循零级反应动力学,其降解速率常数为16 1162mg·L-1·h-1.  相似文献   

6.
利用具有降解己烯雌酚(diethylstilbestrol,DES)特性的功能微生物来降解DES、有望实现环境中DES的有效去除,然而迄今关于降解DES的功能菌株及其降解特性的报道很少.本研究通过选择性富集培养,从某污水处理站活性污泥中分离获得1株具有DES降解特性的细菌(菌株S).经形态观察、生理生化试验及16S rDNA序列同源性分析将菌株S鉴定为沙雷氏菌属(Serratia sp.)细菌.菌株S好氧生长,30℃、150 r·min-1摇床培养7 d后,对无机盐培养基中DES(50 mg·L-1)的降解率达68.3%.通过摇瓶实验,优化了菌株S生长和降解DES的最适环境条件:温度30℃,底物浓度40~60 mg·L-1,pH 7.0,接种量5%,盐添加量0 g·L-1,装液量10 mL(100 mL三角瓶).  相似文献   

7.
低温硝基苯降解菌的筛选及降解特性研究   总被引:13,自引:3,他引:13  
从被硝基苯污染的某河流底泥中分离到能在低温下生长并能以硝基苯为唯一碳源的7株细菌,其中菌株NB1在温度从2.5~35 ℃范围内时都可以生长并矿化20 mg/L的硝基苯,最适宜的生长温度为25 ℃左右;当培养温度为5 ℃时,该菌株在pH为6~9范围内可以快速降解20 mg/L硝基苯,偏碱性的条件比酸性条件更适合其生长;不超过100 mg/L的硝基苯可以被该细菌完全降解.通过生理生化反应特性、菌体形态以及16S rDNA序列测定结果,确定NB1为恶臭假单胞菌(Pseudomonas putida).不同温度条件,特别是低温下该菌株对硝基苯的快速降解特性为低温环境硝基苯污染的生物修复提供了可能.  相似文献   

8.
从环氧树脂废水生化处理系统的活性污泥中分离筛选得到2株嗜盐菌,并对其进行分子生物学鉴定,考察了生长和降解特性.结果表明,通过菌株的形态观察及16S rDNA序列比对分析,菌株J1归属于芽孢杆菌属(Bacillus sp.),菌株J2属于枝芽孢杆菌属(Virgibacillus sp.).菌株J1和J2在高盐CM培养基中的适宜生长条件为:温度30℃,pH为7.0,NaCl的浓度范围为5~50 g.L-1.对环氧树脂废水中有机物的最佳降解条件为:温度30℃,pH为7.0,NaCl浓度30 g.L-1.将菌悬液J1和J2按2∶1的体积比例混合后,在复合菌种的接入量为10%时,对环氧树脂废水中COD的去除率最高.  相似文献   

9.
两株毒死蜱降解细菌的分离鉴定及其降解特性   总被引:5,自引:2,他引:3       下载免费PDF全文
采用富集培养的方法,从农药生产企业的废水处理系统中分离驯化出两株能够降解毒死蜱的菌株HY-2与HY-4,在形态特征和生理生化分析的基础上,又对其16S rDNA序列进行了分析,并研究了其对毒死蜱和其它有机磷农药的降解特性.结果表明,2个菌株均属蜡状芽孢杆菌(Bacillus cerens),HY-4对毒死蜱的降解能力大于HY-2.2个菌株降解毒死蜱的适宜条件为:外加葡萄糖浓度3g·L-1,培养温度35℃,初始pH值8.0,毒死蜱初始浓度80mg·L-1,接种量20%(体积比,菌体密度:稀释到所配菌悬母液(OD600=2)的0.5倍).酵母膏含量对降解的影响表明,当添加3g·L-1的葡萄糖时,最适的酵母膏含量为1g·L-1,而不添加葡萄糖时,最适的酵母膏含量为5g·L-1.2个菌株对甲基对硫磷的降解研究发现,HY-2和HY-4对初始浓度为100mg·L-1的甲基对硫磷60h的降解率分别达64.7%和88.7%;然而,2个菌株对初始浓度为100mg·L-1的三唑磷60h的降解率仅为13.3%-14.2%,降解率较低.  相似文献   

10.
赵雷  马军  刘正乾  孙志忠  侯艳君 《环境科学》2008,29(5):1233-1238
考察了有机物甲醛、甲醇、甲酸和邻苯二甲酸二丁酯对单独臭氧氧化和蜂窝陶瓷催化臭氧化工艺去除水中硝基苯降解效果的影响规律.单独臭氧氧化和蜂窝陶瓷催化臭氧化对硝基苯的去除率随着甲醛浓度的升高(0~12 mg·L-1)分别降低了11.6%和9.6%;2种工艺对硝基苯的去除率都随着甲醇浓度的增加(0~16mg·L-1,)先增高再降低,单独臭氧氧化和蜂窝陶瓷催化臭氧化分别在浓度为2 mg·L-1和4 mg·L-1时去除率达到最大值;随着甲酸浓度的增加(0~8 mg·L-1)去除率也都先增高再降低,单独臭氧氧化和蜂窝陶瓷催化臭氧化分别在浓度为0.5 mg·L-1和2 mg·L-1时去除率达到最大值;低浓度的甲醇和甲酸促进了硝基苯的降解,高浓度的甲醇和甲酸抑制了硝基苯的降解.单独臭氧氧化和蜂窝陶瓷催化臭氧化在邻苯二甲酸二丁酯浓度增加(0~10 mg·L-1)的情况下对硝基苯的去除率分别降低了19.7%和18.6%.  相似文献   

11.
Several main metabolites of benzo[a]pyrene (BaP) formed by Penicillium chrysogenum, Benzo[a]pyrene-1,6-quinone (BP 1,6- quinone), trans-7,8-dihydroxy-7,8-dihydrobenzo[a]pyrene (BP 7,8-diol), 3-hydroxybenzo[a]pyrene (3-OHBP), were identified by high-performance liquid chromatography (HPLC). The three metabolites were liable to be accumulated and were hardly further metabolized because of their toxicity to microorganisms. However, their further degradation was essential for the complete degradation of BaP. To enhance their degradation, two methods, degradation by coupling Penicillium chrysogenum with KMnO4 and degradation only by Penicillium chrysogenum, were compared; Meanwhile, the parameters of degradation in the superior method were optimized. The results showed that (1) the method of coupling Penicillium chrysogenum with KMnO4 was better and was the first method to be used in the degradation of BaP and its metabolites; (2) the metabolite, BP 1,6-quinone was the most liable to be accumulated in pure cultures; (3) the effect of degradation was the best when the concentration of KMnO4 in the cultures was 0.01% (w/v), concentration of the three compounds was 5 mg/L and pH was 6.2. Based on the experimental results, a novel concept with regard to the bioremediation of BaP-contaminated environment was discussed, considering the influence on environmental toxicity of the accumulated metabolites.  相似文献   

12.
Sorption of chlorotoluron in ammonium sulfate, urea and atrazine multi-solutes system was investigated by batch experiments. The results showed application of nitrogen fertilizers to the soil could affect the behavior of chlorotoluron. At the same concentration of N, sorption of chlorotoluron decreased as the concentration of atrazine increased on the day 0 and 6 in soil, respectively. The sorption of chlorotoluron increased from 0 to 6 d when soils were preincubated with deionized water, ammonium sulfate and urea solution for 6 d. That indicated incubation time was one of the most important factors for the sorption of chlorotoluron in nitrogen fertilizers treatments. The individual sorption isotherms of chlorotoluron in rubbery polymer and silica were strictly linear in single solute system, but there were competition sorption between pesticides or between pesticides and nitrogen fertilizers. That indicated the sorption taken place by concurrent solid-phase dissolution mechanism and sorption on the interface of water-organic matter or water-mineral matter.  相似文献   

13.
Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis (DGGE) and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity (both in gene richness and diversity index values) and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor (50 mg/kg) recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos (150 mg/kg) caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos (250 mg/kg) produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes (bands) responded differently to the impact of agrochemicals: four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.  相似文献   

14.
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.  相似文献   

15.
Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury (HgT), combinative mercury (Hgc) and gaseous mercury (HgG), and content of total organic carbon (TOC), but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of (HgG,/HgT)1992〉(HgG/HgT)1996〉〉(HgG/HgT)2000. A simple outline of Hg release in landfill could be drawn: with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants (e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum) are capable of enriching more Hg than herbaceous plants.  相似文献   

16.
Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.  相似文献   

17.
The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.  相似文献   

18.
A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p < 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.  相似文献   

19.
Decomposition of alachlor by ozonation and its mechanism   总被引:1,自引:0,他引:1  
Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.  相似文献   

20.
The influence of the nonionic surfactant Tween 80 on pentachlorophenol (PCP) oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration (CMC). Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.  相似文献   

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