几种蔬菜汞富集能力的初步研究

对莴苣、木耳菜、黄瓜、辣椒、豇豆、四季豆六种夏季蔬菜汞吸收能力研究发现，在田间自然状态下，六种蔬菜植株总汞平均含量为０．００３４７～０．００６３７ｍｇ／ｋｇ，其中辣椒总汞平均含量最高，黄瓜最低；其总汞在蔬菜各部位的分布量以可食部分为主，在叶菜类可食部分分布＞６８％、豆菜类及果菜类＞５９％。盆栽试验表明，三种幼苗中辣椒吸汞能力最强，莴苣最弱，但它在大气汞浓度为５６．７±１４．７ｎｇ／ｍ３下，叶片含汞０．０１２７ｍｇ／ｋｇ，超过食品卫生标准（ＧＢ２８６７－８７，０．０１ｍｇ／ｋｇＦＷ）；当土壤和大气的汞浓度同时很高时，蔬菜植株含汞量大幅增加，这必将使更多的汞进入食物链，并危害生态系统。     

福建省海岩带沉积特中化学要素的分布特征

１９８５年的调查结果表明，福建省海岸带沉积物中总汞、铜、铅、锌、镉、油类、六六六、ＤＤＴ、硫化物、有机质的平均质量分数分别为０．０４６×１０＾－６，１８．２×１０＾－６，２７．７×１０＾－６，８５．６×１０＾－６，０．０７５×１０＾－６，２０．４×１０＾－６，０．００８３×１０＾－６，０．００７３×１０＾－６和１．１８％。Ｒ型聚类分析和因子分析的结果表明：陆地侵蚀风化产物是福建省海岩带沉积物重金属     

装饰材料所致的室内空气污染

对商业、工业、住宅等不同功能区和不同室内燃料的厨房、卧室、教室等室内房间，作了空气中甲醛的本底值调查。调查表明，甲醛浓度范围为０．０００７－０．０１２５ｍｇ／ｍ＾３。对１５户普通家庭装潢户的调查表明，经装潢后１年以上测得的甲醛，总烃、苯、甲苯平均浓度分别为０．０２、０．５０、０．７６、１．２５ｍｇ／ｍ＾３。氯乙烯、苯乙烯未测出。其中甲醛平均浓度高出本底值２０倍，为前苏联建议的日平均浓度的１．６倍。     

宁波市蔬菜污染状况及防治对策

通过对宁波市蔬菜基地的蔬菜中有害物残留和累积状况的调查发现，菜区土壤及蔬菜都不同程度地受到了硝酸盐，重金属等有这物质的污染，其污染程度随物质类型、性质及数量而不同。如蔬菜中硝酸盐含量平均达８１７ｍｇ／ｋｇ，亚硝酸盐平均为０．８２ｍｇ／ｋｇ，平均超标率分别为４７．６％和２８．６％；重金属中铜，镉、铬的超标率都在６０％以上。这种状况对人体健康含有潜在的威胁。必需有效地控制和加以防治，文章最后提出了一些     

硒对汞在稀有Juq鲫体内积累动力学影响

通过增加饲料中亚硒酸钠的含量，研究了硒对氯化汞在稀有Ｊｕ鲫体内积累动力学的影响，探讨了硒对汞富集的影响机制，并给出了两种硒浓度下汞的积累方程，结果表明，饲料中０．２ｍｇ／ｋｇ的硒对鱼体汞富集无明显影响，２．０ｍｇ／ｋｇ的硒使鱼体汞富集增加。并且高硒饲料降低了鱼对汞的排除常数，使鱼体总汞的稳态含量增大。     

硒对汞在稀有鲫体内积累动力学影响

通过增加饲料中亚硒酸钠的含量，研究了硒对氯化汞在稀有鲫体内积累动力学的影响，探讨了硒对汞富集的影响机制，并给出了两种硒浓度下汞的积累方程。结果表明，饲料中０．２ｍｇ／ｋｇ的硒对鱼体汞富集无明显影响，２．０ｍｇ／ｋｇ的硒使鱼体汞富集增加。并且高硒饲料降低了鱼对汞的排除常数，使鱼体总汞的稳态含量增大。     

有机肥和化肥对蔬菜中五项指标的影响

为搞清肥料对蔬菜品质的影响，针对影响蔬菜品质的五种指标做了分析。对施用有机肥和施用化肥对黄瓜中对铅、镉、汞、砷四种指标进行比对，并用t检验的方法，对亚硝酸盐进行了检验。为无公害蔬菜生产提供依据。     

上海市自来水中铀浓度调查

测定自来水中铀浓度及其变化规律，对评估饮用水质量及公众接受的铀放射水平有较大意义。该文介绍了经过一年连续监测所获得的上海市自来水中铀浓度及其变化。结果表明，上海市自来水中铀浓度在０．０２５￣０．２８μｇ／Ｌ之间，年均值为０．１１２μｇ／Ｌ；一年中的１２月－１５月浓度较高，６－１１月浓度略低，其中３月份浓度最高，８月份深度最低，上海市自来水中铀浓度较低，比全国平均浓度低一个数量级。     

蔬菜对大气汞和土壤吸收的研究

通过田间观测和盆栽试验研究了蔬菜富集汞的特性及土壤、大气对蔬菜汞的贡献。对田间 11种蔬菜的研究发现 ,蔬菜根和叶的含汞浓度高于茎和果 ;在自然条件下 ,蔬菜所吸收的汞 60 %以上分布于地上部的可食部分。盆栽试验结果表明 ,在气汞浓度为 5 7.6± 14.7ng· m- 3条件下 ,红萝卜、莴苣叶 (可食部分 )的含汞浓度超过了食品卫生标准 ;气汞、土壤汞对蔬菜汞的贡献率分别为 70 .4～ 90 .7%、9.3～ 2 9.6% ,气汞较土壤汞是蔬菜更为重要的汞源     

福建省海岸带沉积物中化学要素的分布特征

１９８５年的调查结果表明，福建省海岸带沉积物中总汞、铜、铅、锌、镉、油类、六六六、ＤＤＴ、硫化物、有机质的平均质量分数分别为０．０４６×１０￣（－６）、１８．２×１０￣（－６）、２７．７×１０￣（－６）、８５．６×１０￣（－６）、０．０７５×１０￣（－６）、２０．４×１０￣（－６）、０．００８３×１０￣（－６）、０．００７３×１０￣（－６）、３１．８×１０￣（－６）和１．１８％。Ｒ型聚类分析和因子分析的结果表明：陆地侵蚀风化产物是福建省海岸带沉积物重金属和有机质的主要来源；海上交通和工业污染物是油类和硫化物的主要来源，而且这种污染物已部分影响铅的分布；六六六和ＤＤＴ则源自农业上使用有机氯农药通过迳流等携带入海。本文还通过Ｑ型聚类分析对沉积物样品进行了分类，发现泉州湾海区受各种污染物的影响较为明显。     

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.