藻类的三维荧光光谱辨别及算法研究

采用三维荧光技术分析了栅藻,微囊藻和小环藻的色素组成.通过对3种藻的特殊激发谱线的分析,采用435,485,525,630nm作为叶绿素a、叶绿素b、叶绿素c与藻蓝胆素的特征激发波长,采用684nm作为发射波长,建立了3种藻叶绿素浓度与藻密度的荧光强度矩阵方程.根据水样的标准荧光光谱和4个激发波长可以计算出每种藻类的叶绿素浓度与藻密度.     

渤海油类测试中标准油的选择研究

本文对渤海油类测试中标准油的选择进行研究。选取5种原油,11种成品油,1种人工配制油。荧光光谱技术:分别记录310nm、290nm、250nm激发波长时荧光发射谱;室内模拟水中溶解/分散油、沉积物中油的荧光发射谱,获得各类型油的最佳荧光发射波长、发射特性及光谱指纹图。 记录并剖析了渤海海区各站位水体中溶解/分散油、沉积物中油的各波长荧光发射谱。参照ASTM(美国试验与材料学会)溢油鉴别原则,进行了峰形,峰位,指纹综合分析,认为在渤海海区油污染测试中,可用20号重柴油作标准油。     

污染扩散的示踪剂罗丹明—B的试验

荧光分光光度计激发光为552nm,狭缝宽为10nm;发射光为578nm,狭缝宽为10nm时,可准确测定示踪剂罗丹明-B 的浓度,方法简捷,最低检出限为0.15μg/l。     

流动注射荧光检测法测定河水中溶解的腐殖质

河水中溶解的腐殖质是构成溶解有机碳的主要成分,一般由腐殖酸和灰黄霉酸组成。这些物质的定量测定是河流管理的重要依据之一。目前测定腐殖质的方法主要是紫外吸收测定法和荧光测定法。最近W.A.McCrum建立了一种流动注射荧光检测法,该方法是由Brun和Millburn设计的自动分析仪发展而来的。手工操作可采用简易的单线流动注液系统,自动分析可采用由集合管组成的自动连续流动注液系统。检测器是装有高压液相色谱流动池的荧光分光光度计。通过样品的荧光响应(激发波长270nm,发射波长460nm)与技术级腐殖酸标准的荧光响应比较而测定。 测定腐殖质时使用含有柠檬酸钠-酒石酸钾钠络合物的硼酸钠缓冲液(pH10.5),柠檬酸钠-酒石酸钾钠络合物能消除三价铁的干扰并防止金属氢氧     

分子荧光光度法直接测定水中十二烷基本磺酸钠

本文用分子荧光光度法直接测定水中十二烷基苯磺酸钠的含量,不需显色与萃取。本法简便、快速、最大激发波长为EX=230nm,最大发射波长EM=290nm。检出限达32μg/L,回收率为100～101%。     

冰封期前后河流底泥中溶解性有机物组分的荧光特性的变化

以沈阳市新开河为研究对象,考察了冰封期前、后河流底泥中溶解性有机物(DOM)组分荧光特性的变化.按照DOM在XAD树脂上的吸附特性将其分为5个部分:疏水性有机酸(HPO-A)、疏水性中性有机物(HPO-N)、过渡亲水性有机酸(TPI-A)、过渡亲水性中性有机物(TPI-N)和亲水性有机物(HPI).结果表明:HPO-A是河流底泥中的主要DOM组分,在冰封期前、后分别占溶解性有机碳(DOC)的41.2%~69.5%和38.9%~63.9%.冰封期前河流底泥中的DOM及HPO-A、HPI的DOC值均高于冰封期后.三维荧光光谱结果显示,冰封期前、后河流底泥DOM组分中含有类腐殖酸荧光物质,类富里酸荧光物质,类芳香族蛋白质荧光物质和类溶解性微生物代谢产物荧光物质,并且类芳香族蛋白质荧光物质在各DOM组分中的含量最高.冰封期后HPO-A、HPI中荧光物质的含量低于冰封期前.同步荧光光谱结果显示,在冰封期河流底泥DOM组分中激发波长分别为285~295 nm和330~350 nm的荧光物质向水体释放,导致其在底泥DOM组分中相对含量的显著降低.     

污水氯和二氧化氯消毒过程中溶解性有机物变化的三维荧光光谱解析

采用三维荧光光谱（3DEEM）技术对污水在氯和二氧化氯消毒过程中溶解性有机物（DOM）的变化进行了初步解析.结果表明,与饮用水、地表水等不同,生物处理出水含有较多的芳香族蛋白质和溶解性微生物代谢产物,且其中的腐殖质主要为生物源,芳香性较弱.在氯和二氧化氯消毒后,污水DOM中的芳香族蛋白质和微生物代谢产物类物质的荧光峰发生蓝移,即峰值的激发或发射波长减少了几个nm,这可能由芳香环结构的破坏引起;而腐殖质类物质的荧光峰发生红移,即峰值的激发或发射波长增加了几个到二十几个nm,此现象与地表水相反,可能与腐殖质的来源不同有关.与遗传毒性的变化类似,氨氮对水样氯消毒后的荧光变化有明显影响,但对二氧化氯消毒后的荧光变化无明显影响.     

海上溢油鉴别方法的研究——用荧光分光光度法对各种类型的石油进行分类的研究

对各种类型的原油及成品油的分类的研究是用荧光分光光度法进行的。 首先,我们以无荧光环已烷为溶剂配制了浓度分别为1/1万,1/2万和1/10万的标准油溶液。 我们用日立650—60型荧光分光光度计进行了测空,在激发波长340nm,对发射波长300—500nm进行扫描。 检查了约七十种原油,发现它们按荧光光谱的峰值比440/385可分为六类(3—8类)。对深色成品油(重紫油,船用紫油和用过的润滑油)来说,可用它们的谱图和440/385峰值比来鉴定其类似性。但对淡色成品油(汽油,灯油,轻油和新的润滑油)则必须用特殊操作进行分析。 本法可以当做一种鉴定手段应用于鉴别排放到海洋中的原油和成品油的种类和类似性。     

河口区溶解有机物三维荧光光谱的平行因子分析及其示踪特性

利用激发发射矩阵荧光光谱(EEMs)并结合平行因子分析(PARAFAC),研究了九龙江口有色溶解有机物(CDOM)的荧光组分特征及其河口动力学行为,并探讨其作为河口区有机污染示踪指标的可行性.利用PARAFAC模型识别出九龙江口CDOM由2类4个荧光组分组成,即类腐殖质荧光组分C1(240,310/382nm)、C2(230,250,340/422nm)、C4(260,390/482nm)及类蛋白质荧光组分C3(225,275/342nm).模型结果表明,传统寻峰法指认的短波类腐殖质A峰区域(240～290/380～480nm)实际上并非一个单独的荧光峰,而是若干荧光组分的组合,并且它与传统上指认的长波区海源类腐殖质M峰、陆源类腐殖质C峰之间存在内在联系.包含M峰的C1组分在河口区随盐度增加呈稀释降低趋势,表明M峰并不能被认为是海洋来源的专有特征峰.类腐殖质组分C1和C2在盐度6的河口最大浑浊带区表现出一定的添加行为,之后在河口混合过程中呈保守行为,而类腐殖质荧光组分C4则在整个河口混合过程中都呈保守行为.类蛋白质荧光组分C3在河口混合过程中呈不保守行为,并且在总荧光组分中所占比例在高盐度区呈上升趋势.EEM-PARAFAC不仅可示踪九龙江不同支流DOM的特征,并且还可很好地示踪九龙江口的有机污染程度.     

荧光溶解性有机质EEMs的新旧自组织映射图解析方法比较研究

目前,对地表水体荧光溶解性有机质(Fluorescent Dissolved Organic Matter,FDOM)三维激发发射矩阵(Excitation-Emission Matrices,EEMs)数据的解析仍旧存在挑战.本文结合原始EEMs和从中分离的荧光平行因子分析(Parallel Factor Analysis,PARAFAC)组分,利用自组织映射图(Self-Organizing Maps,SOM),开展了基于传统EEMs-SOM和新型PARAFAC-SOM神经网络模型的复杂荧光数据解析能力对比研究,以此探索和改进EEMs多元解析方法技术体系.模型以已发表论文原始数据为基础构建,研究对象为南太湖重要入湖河流东苕溪水系.结果显示:EEMsSOM模型需依赖常规"摘峰法"对各荧光峰做出主观判断,不能有效识别重叠荧光峰,且人为割裂多激发共发射荧光物质峰之间的联系,从而弱化分析结果的实际环境意义,但神经元的模式荧光光谱可视化效果较佳,且操作简便,耗时较少;PARAFAC-SOM模型克服了上述缺陷,可清除EEMs中的噪声或无用信息,大幅降低输入变量数(从1742个降至4个),缩减运算时间,较大地改善了输出结果的准确性,获得无损可靠且实际环境意义较强的结果,但该法的PARAFAC预处理要求较高,工作量较大;两类模型解析结论大体一致,对前期研究进行了全新的阐述和补充,且生动揭示了FDOM在多级河流水体中的空间赋存变化规律及河流的动态污染过程.综上,推荐在今后研究中综合使用两类优势互补的模型以实现对EEMs的深度解析.     

Toxic effects of acetochlor, methamidophos and their combination on nifH gene in soil

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.     

Arsenic uptake by arbuscular mycorrhizal maize （Zea mays L.） grown in an arsenic-contaminated soil with added phosphorus

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.     

Impact of atrazine and nitrogen fertilizers on the sorption of chlorotoluron in soil and model sorbents

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.     

Degradation of metabolites accumulated of benzo[a]pyrene by coupling Penicillium Chrysogenum with KMnO4

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.     

Potential of plant polyphenol oxidases in the decolorization and removal of textile and non-textile dyes

In this study an effort has been made to use plant polyphenol oxidases; potato （Solanum tuberosum） and brinjal （Solanum melongena）, for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.     

Removal of heavy metals from sewage sludge by low costing chemical method and recycling in agriculture

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Isolation and preliminary characterization of a 3-chlorobenzoate degrading bacteria

A study was conducted to compare the diversity of 2-, 3-, and 4-chlorobenzoate degraders in two pristine soils and one contaminated sewage sludge. These samples contained strikingly different populations of mono-chlorobenzoate degraders. Although fewer cultures were isolated in the uncontaminated soils than contaminated one, the ability of microbial populations to mineralize chlorobenzoate was widespread. The 3- and 4-chlorobenzoate degraders were more diverse than the 2-chlorobenzoate degraders. One of the strains isolated from the sewage sludge was obtained. Based on its phenotype, chemotaxonomic properties and 16S rRNA gene, the organism S-7 was classified as Rhodococcus erythropolis. The strain can grow at temperature from 4 to 37℃. It can utilize several （halo）aromatic compounds. Moreover, strain S-7 can grow and use 3-chlorobenzoate as sole carbon source in a temperatures range of 10-30℃ with stoichiometric release of chloride ions. The psychrotolerant ability was significant for bioremediation in low temperature regions. Catechol and chlorocatechol 1,2-dioxygenase activities were present in cell free extracts of the strain, but no （chloro）catechol 2,3- dioxygenase activities was detected. Spectral conversion assays with extracts from R. erythropolis S-7 showed accumulation of a compound with a similar UV spectrum as chloro-cis,cis-muconate from 3-chlorobenzoate. On the basis of these results, we proposed that S-7 degraded 3-chlorobenzoate through the modified ortho-cleave pathway.     

Single and joint effects of pesticides and mercury on soil urease

The influence of two pesticides including chlorimuron-ethyl and furadan and mercury （Hg） on urease activity in 4 soils （meadow burozem and phaeozem） was investigated. The soils were exposed to various concentrations of the two pesticides and Hg individually and simultaneously. Results showed that there was a close relationship between urease activity and organic matter content in soil. Chlorimuron-ethyl and furadan could both activate urease in the 4 soils. The maximum increment of urease activity by chlorimuronethyl was up to 14%-18%. There was almost an equal increase （up to 13%-21%） in the urease activity by furadan. On the contrary, Hg markedly inhibited soil urease activity. A logarithmic equation was used to describe the relationship （P〈0.05） between the concentration of Hg and the activity of soil urease in the 4 tested soils. Semi-effect dose （ED50） values by the stress of Hg based on the inhibition of soil urease in the 4 soils were 88, 5.5, 24 and 20 mg/kg, respectively, according to the calculation of the corresponding equations. The interactive effect of chlorimuron-ethyl or furadan with metal Hg on soil urease was mainly synergic at the highest tested concentrations.     

Organochlorine pesticides in soils under different land usage in the Taihu Lake region, China

A field study was conducted in the Taihu Lake region, China in 2004 to reveal the organochlorine pesticide concentrations in soils after the ban of these substances in the year 1983. Thirteen organochlorine pesticides (OCPs) were analyzed in soils from paddy field, tree land and fallow land. Total organochlorine pesticide residues were higher in agricultural soils than in uncultivated fallow land soils. Among all the pesticides, ΣDDX (DDD, DDE and DDT) had the highest concentration for all the soil samples, ranging from 3.10 ng/g to 166.55 ng/g with a mean value of 57.04 ng/g and followed by ΣHCH, ranging from 0.73 ng/g to 60.97 ng/g with a mean value of 24.06 ng/g. Dieldrin, endrin, HCB and α-endosulfan were also found in soils with less than 15 ng/g. Ratios of p,p'-(DDD DDE)/DDT in soils under three land usages were: paddy field ＞ tree land ＞ fallow land, indicating that land usage inlfuenced the degradation of DDT in soils. Ratios of p,p'-(DDD DDE)/DDT ＞1, showing aged residues of DDTs in soils of the Taihu Lake region. The results were discussed with data from a former study that showed very low actual concentrations of HCH and DDT in soils in the Taihu Lake region, but according to the chemical half-lives and their concentrations in soils in 1980s, the concentration of DDT in soils seemed to be underestimated. In any case our data show that the ban on the use of HCH and DDT resulted in a tremendous reduction of these pesticide residues in soils, but there are still high amounts of pesticide residues in soils, which need more remediation processes.     

Alterations of organ histopathology and metallolhionein mRNA expression in silver barb, Puntius gonionotus during subchronic cadmium exposure

Common silver barb,Puntius gonionotus,exposed to the nominal concentration of 0.06 mg/L Cd for 60 d,were assessed for histopathological alterations(gills,liver and kidney),metal accumulation,and metallothionein(MT)mRNA expression.Fish exhibited pathological symptoms such as hypertrophy and hyperplasia of primary and secondary gill lamellae,vacuolization in hepatocytes,and prominent tubular and glomerular damage in the kidney.In addition,kidney accumulated the highest content of cadmium,more than gills and liver.Expression of MT mRNA was increased in both liver and kidney of treated fish.Hepatic MT levels remained high after fish were removed to Cd-free water.In contrast,MT expression in kidney was peaked after 28 d of treatment and drastically dropped when fish were removed to Cd-free water.The high concentrations of Cd in hepatic tissues indicated an accumulation site or permanent damage on this tissue.