Effects of macronutrient additions on nickel uptake and distribution in the dinoflagellate Prorocentrum donghaiense Lu

The influences of macronutrient additions on nickel (Ni) uptake and distribution in the subcellular structures and macromolecular components of the dinoflagellate Prorocentrum donghaiense Lu were examined using a radioisotope tracer method. The results showed that nitrate addition enhanced the uptake of Ni by P. donghaiense, whereas phosphate addition inhibited Ni uptake at high-Ni concentration. Nitrate or phosphate addition significantly affected Ni distribution in the subcellular structures and components. The majority of Ni was found in the soluble substances (>70%) and in the proteins (55.0-79.6%) of the algal cells. Urea reduced the Ni content in the amino acid-carbohydrate but elevated its content in proteins, and shown significantly correlated with the protein content of the algal cells. Thus, nutrient enrichment could influence both metal uptake and its distribution in the subcellular structures and components of the phytoplankton, as well as its subsequent transfer in marine food chains.     

Dissecting the spatial scales of mercury accumulation in Ontario lake sediment

Total mercury concentration was analyzed in 171 lakes from pre-industrial (>30 cm depth; Hg_{pre-industrial}) and present-day sediments (0.5–1 cm; Hg_present-day). Numerous hot or cold spots of sediment mercury enrichment (Hg EF; Hg_{pre-industrial}/Hg_present-day) were evident as determined by local tests of autocorrelation, although in most cases, the maximum correlation among sites was not the nearest neighbor, indicating a strong influence of watershed characteristics. Hg EF was correlated with the area of open water (ha) (r = 0.91, p = 0.035), mine tailings (r = 0.94, p = 0.019), and organic deposits in surficial geology of the watershed (r = −0.91, p = 0.034). Through use of local rather than global regression coefficients, R² increased from 0.20 (p = 0.005) to 0.60 (p = 0.013). A broad spatial pattern (>500 km) observed only in Hg_{pre-industrial} was best explained by mean annual precipitation (shared variance = 3.5%), while finer spatial patterns only observed in Hg_present-day and Hg EF were best explained by pH (average shared variance = 10.8%).     

常州市春季大气PM2.5中金属元素的分析及污染特征

建立了微波消解-电感耦合等离子体质谱(ICP-MS)法,同时测定大气PM2.5中K、Na、Ca、Mg、Fe、Al、Zn、Si、Ti、V、Cr、Mn、Co、Ni、Cu、As、Cd和Pb等18种金属元素的分析方法.样品用HNO3+H2O2(5∶1)经微波消解系统进行前处理.该方法操作方便,酸用量少,由于是密闭消解,对环境污染也少.经过反复调试,确定了仪器最佳操作条件.结果表明,各种元素标准曲线的线性相关系数均在0.9990以上,方法检出限在0.07 μg/L ～1.16 mg/L之间,精密度实验中各元素的RSD均小于7.53％,回收率在91.38％～117.53％之间.该方法能够快速有效地实现多元素同时测定,检测线性范围宽,测试结果准确可靠,可以应用于大气颗粒物中多种金属元素的测定.采用富集因子分析法对常州市大气中PM25做来源分析表明,常州市大气PM25中,大部元素的富集因子都大于10,其中,Ni、Cu、Zn、As、Cd、Co和Pb在各个采样点的富集因子都非常高,表明主要来自于人为污染.     

The treatment of black-odorous water using tower bipolar electro-flocculation including the removal of phosphorus,turbidity, sulfion,and oxygen enrichment

• An innovative bubble column tower BPE was designed to treat the black-odorous water. • PO₄³⁻, S²⁻ and turbidity were removed, and dissolved oxygen was enriched in the BPE. • An aluminum bipolar electrode gave the best oxygen enrichment and pollutant removal. • Changes of microorganisms confirmed the improvement in water quality achieved. The large amount of municipal wastewater discharged into urban rivers sometimes exceeds the rivers’ self-purification capacity leading to black-odorous polluted water. Electro-flocculation has emerged as a powerful remediation technology. Electro-flocculation in a bubble column tower with a bipolar electrode (BPE) was tested in an attempt to overcome the high resistance and weak gas-floatation observed with a monopolar electrode (MPE) in treating such water. The BPE reactor tested had a Ti/Ta₂O₅-IrO₂ anode and a graphite cathode with an iron or aluminum bipolar electrode suspended between them. It was tested for its ability to reduce turbidity, phosphate and sulphion and to increase the concentration of dissolved oxygen. The inclusion of the bipolar electrode was found to distinctly improved the system’s conductivity. The system’s electro-flocculation and electrical floatation removed turbidity, phosphate and sulphion completely, and the dissolved oxygen level improved from 0.29 to 6.28 mg/L. An aluminum bipolar electrode performed better than an iron one. Changes in the structure of the microbial community confirmed a significant improvement in water quality.     

六溴环十二烷(HBCDs)异构体和对映体在白洋淀土壤和植物中的选择性富集与传输

利用高效液相色谱-串联三重四级杆质谱分析了白洋淀土壤和植物中六溴环十二烷（HBCDs）异构体和对映体的选择性富集分布及传输特征.土壤和植物样品中ΣHBCD浓度分别为1.32~8.25 ng·g^-1（干重）和N.d.~2.18 ng·g^-1（干重）;在采蒲台（CPT）、圈头（QT）和范峪淀（FYD）检测到的污染物浓度较高,表明南部土壤污染较北部严重;与国内外其他区域相比,白洋淀地区HBCDs的污染水平相对较低.淀区HBCDs的富集存在显著的异构体和对映体选择性行为,γ-HBCD和α-HBCD分别是土壤和植物中的主要异构体,平均百分比贡献率分别为68.24%和44.10%;在多数土壤和植物样品中均表现出（-）-HBCD比（+）-HBCD更易于被选择性富集.ΣHBCD从土壤到植物根系的传输RCFs（根富集因子）为0.12~0.93,其中泥胡草对HBCDs的富集能力最强,荠菜最弱;植物根部到地上部的传输系数（TFs）为0.09~0.81,植物茎向传输能力为补血草 > 牛筋草 > 荠菜 > 泥胡草.HBCDs异构体在土壤-植物体系的RCFs与log K_ow,TFs与log K_ow之间均未发现显著的相关性,可能是由于植物物种的差异和复杂的真实环境的影响.本研究首次为白洋淀淀区土壤-植物体系中HBCDs的污染及其立体选择性行为提供依据,对该地区综合评估其生态安全风险和持久性有机污染物（POPs）的污染防治具有重要意义.     

海河干流（市区段）表层沉积物重金属污染及变化趋势分析

根据1990—2006年监测资料,对海河干流（市区段）沉积物中重金属的现状和变化趋势进行了分析,采用地积累指数和Hakanson危害指数对海河干流（市区段）沉积物重金属富集现状和对水生生物危害进行评估。结果显示：海河干流（市区段）表层沉积物除Zn外,均呈现污染下降趋势。海河干流（市区段）沉积物中重金属对生物潜在危害顺序为Cd〉Hg〉As〉Cu〉Pb〉Cr〉Zn,各项指标对生物潜在危害性上游大于下游。     

富锌金针菇菌株的诱变选育及酶谱分析

以金针菇F19为出发株,通过制备菌丝断片悬液和紫外线照射(3—14min)来筛选突变株。结果发现,12min处理使菌丝体生物量减少了5.14%(p>0.05),但富锌量提高了18.78%(p<0.01);在连续3代的遗传稳定性实验中,菌丝体生物量为1.342—1.419g/100ml,富锌量为49.78—50.45mg/g,与原代差异均不显著(p>0.05)。PAGE技术测定发现,EST是金针菇遗传分析最适标记之一;高锌通过提高EST、POD的合成和活性来促进有机锌的转化和菌丝体的生长。     

北方某市环境空气颗粒物中重金属污染状况研究

对我国北方某市大气颗粒物的污染状况进行了研究。在主导风向上设置采样点,于冬季、夏季分别采集TSP、PM₁₀、PM_2.5 3种不同动力学直径的大气颗粒物。采用ICP-MS对TSP、PM₁₀、PM_2.5中的元素浓度进行分析,并对3种不同粒径颗粒物中的10种重金属采用富集因子法进行评价。结果表明,北方某市环境空气颗粒物中富集程度最严重的为Cd、Pb;在采暖期,随着颗粒物粒径变小,Pb、Cd的富集指数呈现逐渐增大的趋势;非采暖期则无此趋势。     

南昌市秋季大气PM2.5中金属元素污染及生态风险评价

2013年秋季采集了南昌市6个不同功能区的大气PM_(2.5)样品,分析了PM_(2.5)含量及其中18种金属元素的含量。结果表明:采样期间南昌市大气PM_(2.5)平均质量浓度均在《环境空气质量标准》(GB 3095—2012)日平均浓度限值二级标准规定(75μg/m3)的范围内。PM_(2.5)中多数金属元素的含量水平低于中国内地城市,而与香港和国外城市相比则偏高。分别采用富集因子法和潜在生态风险指数法对重金属污染风险进行了评价。富集因子法表明Zn、Pb、Hg、Cu等元素富集程度较高,Cd富集程度极高,人为源显著;潜在生态风险指数法表明Pb、Hg、Cd潜在生态风险程度为极强,南昌市总体潜在生态风险表现为极强,2种方法的评价结果较为一致。     

中国蔬菜地土壤重金属健康风险基准的研究

对我国目前土壤和蔬菜中重金属污染评价情况进行了综述,根据全国已报道蔬菜地土壤和蔬菜中重金属含量的数据和相关资料,探讨了蔬菜地土壤和蔬菜中重金属含量之间的关系以及不同的蔬菜种类和品种中重金属的积累差异,并在已有土壤和蔬菜中重金属污染的评价指标基础上,对蔬菜地土壤和蔬菜中重金属的健康风险基准值进行了讨论,尤其对我国各地区蔬菜地土壤中重金属的污染指标值进行了统一的限定,可为制订蔬菜地土壤重金属健康风险标准提供科学依据.