羟基自由基杀灭压载水赤潮入侵生物试验研究

采用羟基自由基对斯式根管藻、日本星杆藻、裸甲藻和细菌进行杀灭实验，确定杀灭入侵赤潮生物的所需OH^-比值浓度为0.68mg／L。当OH^-比值浓度达到0．68mg／L时，致死多甲藻(Peri.Spp)等10种赤潮生物效率达到99.8％，致死膝沟孢子、多甲藻孢子效率达到100％。试验数据表明，强电离先进氧化OH^-是治理赤潮有效、可行的绿色新方法。     

海洋污染及其防治

X55200502135强电离先进氧化OH·治理赤潮试验/白敏冬(大连海事大学环境工程研究所)…∥应用与环境生物学报/中科院成都生物研究所.-2004,10(5).-626~630环图X-27采用强电场电离H2O、O2方法,在分子层次上加工成高浓度OH·溶液,喷洒在有赤潮生物的海面上,当海水的羟基比值浓度达到0.68mg/L时,致死洛氏角刺藻(Chaetoceros lorenzianus)等29种赤潮生物效率达到99.89%,致死细菌、弧菌效率达到100%,致死膝沟藻孢子、多甲藻孢子效率达到100%;赤潮生物叶绿素a含量低于检测方法低限值;剩余OH·分解成H2O、O2;尸体将分解成CO2、H2O和微量无机…     

N、P、Mn和Fe对链状裸甲藻生长和产毒的影响

为了解营养盐因子对链状裸甲藻(Gymnodinium catenatum(香港株))的生长和产毒的影响,本文采用单因子实验方法,研究在不同N、P、Mn和Fe浓度条件下,链状裸甲藻生长和产毒情况。结果表明,在N浓度低于300.00 mg/L和P浓度低于20.00 mg/L的范围内,链状裸甲藻的对数生长期和最高细胞数随N、P浓度的增加而升高,对数生长期可达64 d以上,最高细胞数达5.01×103/mL,Mn对链状裸甲藻生长的影响不明显,高浓度Fe和低浓度Fe均不利于链状裸甲藻的生长,最适Fe浓度为3.15 mg/L左右。链状裸甲藻产生的的麻痹性贝类毒素主要成分为C毒素(C1-2)、GTX5(B1)、dcGTX2-3和dcSTX,以低毒性的C毒素和GTX5为主。N、P、Mn和Fe浓度对链状裸甲藻所产毒素的成分种类没有影响,但可影响产毒量及各毒素成分的比例;藻细胞最高产毒量为3.3 pg STX Equal/cell,最低为0.9 pg STX Equal/cell,低P和低Mn有利于藻细胞产毒,高毒力的dcSTX在毒素中的比例也较高。     

烷基糖苷季铵盐选择性抑藻活性研究

以甲藻门的东海原甲藻、塔玛亚历山大藻、裸甲藻,黄藻门的赤潮异弯藻,硅藻门的中肋骨条藻等典型的赤潮生物以及绿藻门的青岛大扁藻和亚心形扁藻两种非赤潮生物为目标生物,探讨了烷基糖苷季铵盐(APG-131)类表面活性剂的抑藻活性。结果表明,该表面活性剂在较低的浓度范围内(0.5 mg/L),对东海原甲藻、塔玛亚历山大藻和赤潮异弯藻等赤潮生物的生长有明显的抑制作用。当该季铵盐的浓度增加至1.0 mg/L以上时,可完全抑制中肋骨条藻的生长,而在相同的浓度范围内,对裸甲藻和所选2种非赤潮生物生长影响不明显,表现出了抑藻作用的种属特异性。结合各海洋微藻的脂肪酸组成分析,证实了该表面活性剂选择性抑藻作用与不同海洋微藻的多不饱和脂肪酸的含量明显相关。     

强氧化自由基杀灭压载水微生物的模拟试验研究

在强电离电场作用下,H2O、O2分子发生电离、分解电离和电荷交换反应,在分子层次上加工成高浓度羟基溶液。试验是在每小时处理2t压载水的试验系统进行的。把羟基溶液加入压载水输送管道内,仅距加入点4m长度地方取样检测,当压载水的羟基比值浓度达到0 63mg/L时,原生动物、单胞藻、细菌浓度分别从4 4×104/mL、6 0×104/mL、1 9×105/mL均减少到低于检测方法的最低限;剩余羟基药剂分解成H2O、O2等。从试验数据表明,羟基溶液是治理压载水有效、廉价、无残留物的创新方法。     

春季东海赤潮高发区尿素的断面分布及影响因素

根据2011年3月31日至5月27日对东海赤潮高发区ZA断面的6次调查数据,分析了该断面赤潮暴发前后尿素的断面分布及影响因素。结果表明:3月31日至4月20日硅藻赤潮暴发期间,尿素的浓度范围为0.06~3.27μmol/L,陆源输入为硅藻赤潮期间影响尿素浓度的主要因素;4月28日至5月27日甲藻赤潮暴发期间,尿素的浓度范围为0.12~3.46μmol/L,浮游植物的吸收利用是影响甲藻赤潮期间尿素浓度的主导因素。调查期间,该断面尿素浓度高值区整体呈现由近岸向远岸,再向近岸转移的分布趋势。且随着时间的推移,该断面尿素浓度整体呈现降低的趋势。根据甲藻赤潮暴发期间,ZA断面尿素浓度低于硅藻赤潮暴发期间,且低值区与叶绿素浓度高值区相对应这一尿素浓度分布特征和浓度水平,推测甲藻对尿素的有效吸收利用是维持东海赤潮高发区甲藻赤潮暴发的原因之一。     

杉木粉对两种赤潮藻去除的试验研究

利用船基围隔试验,探讨了杉木粉对东海原甲藻(Prorocentrum donghaiense Lu)、米氏凯伦藻(Karenia mikimotoi)两种赤潮藻的去除效果.并以斑马鱼(Brachydanio rerio)和卤虫无节幼体(Artemia sinica)为材料,对杉木粉及其有效成分杉木精油的毒性进行了测试.结果显示,杉木粉用量为76.9 mg/L时具有显著去除米氏凯伦藻的作用;浓度为38.4mg/L时可显著去除东海原甲藻.杉木粉对斑马鱼的24 h、48 h半致死浓度分别为2.8 g/L、2.4 g/L,安全浓度为0.6 g/L.利用杉木粉控制赤潮有一定的应用前景.     

两种赤潮藻对SD和SMX的耐受性研究

探讨了海洋中常见药残磺胺嘧啶(SD)和磺胺甲恶唑(SMX)对球形棕囊藻和东海原甲藻生长的影响。结果表明:当这两种磺胺药物浓度大于20 mg/L时,球形棕囊藻和东海原甲藻的生长明显被抑制;SD和SMX对球形棕囊藻半数生长影响的浓度(EC50)分别为60～80 mg/L和20～40 mg/L;SD和SMX对东海原甲藻半数生长影响的浓度分别为20～40 mg/L和40～60 mg/L;两种藻培养96 h时扫描电镜观察,均显示高浓度下藻细胞膜严重破损,说明磺胺药物对其生长具有抑制作用。EC50对比表明球形棕囊藻对SD的耐受性强于SMX,而东海原甲藻对SMX的耐受性强于SD。两种藻对药残的耐受性明显强于其他藻种,在高浓度药残环境中占据生存优势。通过这项研究,试图探讨磺胺药物对河口及近海养殖区赤潮频发和赤潮消亡的影响。     

新洁而灭对海洋原甲藻赤潮生物的灭杀与抑制

研究了十二烷基二甲基卞基溴化铵(新洁而灭)和戊二醛对赤潮生物的灭杀和控制作用。结果表明，新洁而灭可以有效地杀灭海洋原甲藻，浓度0．10mg/L时，可以控制海洋原甲藻的增长，浓度大于0．15mg/L时，除藻率可达到90％以上。戊二醛也具有除藻效果，但作用浓度较高，浓度大于3．0mg/L，除藻率可达到50％以上。戊二醛与新洁而灭复配时具有协同作用，可提高除藻能力。当戊二醛与新洁而灭配比为10：1时，协同指数小于1，协同作用比较明显，戊二醛与新洁而灭可复配使用。     

Bacillus sp.处理含锑废水试验研究

利用某芽孢杆菌属微生物(Bacillus sp).对锑矿选矿废水进行了处理。研究微生物的接种量、作用时间、温度、体系pH值等对废水中Sb的去除效果的影响。结果表明:作用时间4 d、微生物接种量为5%、处理体系pH为2、最佳处理体系温度为30℃时,效果最佳,对废水中Sb的去除率达到99.75%,处理后废水中Sb的浓度由122.21 mg/L降低至0.30 mg/L,出水Sb浓度低于湖南省地方标准排放限值0.50 mg/L。     

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.     

Effects of two sludge application on fractionation and phytotoxicity of zinc and copper in the soil

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.     

Intraspecific differences in effects of co-contamination of cadmium and

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.     

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.