镉胁迫对向日葵幼苗生长和生理特性的影响

采用溶液培养方法,研究了不同浓度镉(0、0.05、0.1、0.5和1 mg/L)处理7 d对向日葵幼苗生长和生理特性的影响。结果表明：随着镉处理浓度的增加，向日葵幼苗对镉的吸收显著增加。1 mg/L镉浓度处理时，叶、茎和根中镉浓度分别为0.05 mg/L镉处理时的16.3、19.2和581倍；根中积累的镉含量明显高于叶和茎, 各浓度根部积累的镉分别为叶和茎的37.8～63倍和29.4～41倍。镉胁迫显著抑制向日葵幼苗生长和叶绿素合成，当镉浓度达1 mg/L时，整株植物生物量和总叶绿素含量分别为对照的55.9%和52.6%。镉胁迫下向日葵幼苗游离脯氨酸和丙二醛（MDA）含量显著增加，1 mg/L镉浓度时，根中含量分别为对照的4和5.8倍。向日葵幼苗可溶性蛋白含量和过氧化物酶(POD)活性变化与镉胁迫浓度呈明显的倒U字型关系，可溶性蛋白含量在0.05 mg/L镉浓度时达到最大值，叶、茎、根中的POD活性分别在0.1、0.1和0.05 mg/L镉浓度时达到最大值。     

脱灰煤基活性炭吸附处理含镉废水

考察了硝酸脱灰煤样自制活性炭对Cd（Ⅱ）的吸附去除特征。结果表明，随煤样粒径的减小，活性炭的吸附能力增强，吸附过程符合分形动力学特征；随着镉浓度的升高，活性炭对镉的吸附量增加，活性炭吸附镉符合Langmuir等温方程，镉离子在活性炭上的吸附属单分子层吸附；煤基活性炭适宜的吸附除镉条件为粒径0．054mm、Cd（Ⅱ）初始浓度35mg／L、活性炭用量0．05g、吸附时间1h，此时的吸附容量达40mg／g。     

城市给水厂常规工艺铬（Ⅵ）去除风险分析与应急处理方法研究

铬（Ⅵ）是突发性水污染常见污染物之一。研究表明，我国给水厂常规工艺出水铬（VI）超标风险较高，当污染强度为0．20m∥L时，投加混凝剂（PAFC）100mg／L，出水铬（VI）浓度为0．10mg／L，无法满足《生活饮用水卫生标准》（GB5749．2006）0．05mg／L的要求。活性炭吸附法不是理想的铬（Ⅵ）应急处理方法，当污染强度为0．114～0．794mg／L时，在未调节原水pH（7～8）的条件下，增加活性炭投加量，去除效果无明显改善，出水铬（Ⅵ）浓度大于0．05mg／L。硫酸亚铁还原沉淀法是可行的铬（Ⅵ）污染应急处理方法，当铬（Ⅵ）污染强度为2．00mg／L，pH为7～8时，投加硫酸亚铁16mg／L，铬（Ⅵ）去除率达99．1％，出水铬（VI）与铁浓度分别为0．019和0．021mg／L，满足标准要求，改变硫酸亚铁投加量可满足不同污染强度下应急处理的需要。     

青萍在Pb、Cu污染水体植物修复中的应用研究

以青萍种浮萍（Lemna perpusilla Torr.）为实验材料,以Pb（Ⅱ）、Cu（Ⅱ）为染毒因子,设定金属离子浓度梯度（Pb（Ⅱ）：0～40 mg/L,Cu（Ⅱ）：0～4 mg/L）,考察了在不同金属离子浓度下青萍生长状况、叶片色素含量以及金属离子浓度对青萍N、P和金属离子吸收能力的影响。结果表明：金属离子浓...     

不同消毒剂对饮用水中可同化有机碳的影响

以某地表水为原水（TOC为5．3mg／L），研究了氯、氯胺和臭氧3种消毒剂对可同化有机碳（AOC）的影响。结果表明，投加1mg／L氯氧化30min就会使AOC升高近3倍。投加3种剂量（1、2、3mg／L）的氯胺，氧化30min时AOC增加不到1倍；氧化24h时AOC浓度均比30min时的高，这说明氯胺的作用机理与氯不同。投加臭氧2．0mg／L氧化30min时可使AOC增加2．4倍；当臭氧质量浓度大于2．0mg／L时，AOC开始下降，这说明一部分中间产物进一步被氧化成了二氧化碳和水。     

脱灰煤基活性炭吸附处理含镉废水简

考察了硝酸脱灰煤样自制活性炭对Cd（Ⅱ）的吸附去除特征。结果表明，随煤样粒径的减小，活性炭的吸附能力增强，吸附过程符合分形动力学特征；随着镉浓度的升高，活性炭对镉的吸附量增加，活性炭吸附镉符合Langmuir 等温方程，镉离子在活性炭上的吸附属单分子层吸附；煤基活性炭适宜的吸附除镉条件为粒径0.054 mm、Cd（Ⅱ）初始浓度35 mg/L、活性炭用量0.05 g、吸附时间1 h，此时的吸附容量达40 mg/g。     

一种新型环境矿物材料在废水治理中的应用研究——硅质磷块岩吸附水溶液中镉离子的研究

硅质磷块岩对水溶液中镉离子的吸附实验结果表明，硅质磷块岩对水溶性镉离子具有良好的去除效果，主要影响因素有：介质的酸度、作用时间、镉离子的初始浓度和样品用量。在pH＝6，作用时间为15min，初始Cd^2 浓度为30mg/L的实验条件下，硅质磷块岩对镉离子的去除率可达98％，有可能利用动态法进行工业废水的连续处理。初步研究结果显示，磷块岩对水溶性镉离子的吸附作用符合Langmuir等温吸附模型，不同产地的硅质磷块岩S1和S2对镉离子的最大吸附容量分别为4．43mg/g和3．88mg/g。     

O3氧化工艺处理黄连素制药废水研究

采用臭氧（O3）氧化法处理含高浓度黄连素和COD的制药废水，探讨了废水初始pH、O3投加量及初始黄连素浓度等因素对O3氧化过程的影响，确定了O3氧化技术处理黄连素制药废水的最佳操作条件。结果表明，O3能够有效分解废水中的黄连素，降低其COD浓度；黄连素浓度为700mg／L、COD为3500mg／L、pH为0．88的废水，进气O3浓度为14．05mg／（L·min），处理时间为180rain（即投加量为2529mg／L）时，黄连素和COD的降解率分别可达77．46％和41．28％，BOD，／COD比（B／C比）从0．06提高到0．34，增加了4．7倍；随着废水中初始黄连素浓度的升高，废水COD降解率逐渐降低。O3氧化法是一种有效的黄连素制药废水预处理技术，可以大大提高废水的可生化性。     

嗜麦芽窄食单胞菌对镉的吸附

利用从重金属镉污染地分离并纯化得到的1株嗜麦芽窄食单胞菌(Stenotrophomonas maltophilia)作为吸附剂,考察了镉初始浓度、菌浓度、吸附时间、温度及pH对镉吸附效果的影响.结果表明,在镉初始质量浓度为1.0 mg/L、30℃、pH为6～7条件下,菌质量浓度为2.0 g/L时,吸附120 min对镉...     

巯基化合物在万寿菊镉解毒中的作用

采用水培实验方法研究了万寿菊体内镉积累和解毒与巯基化合物含量的关系。万寿菊植株分别在镉浓度为0、0.1、0.5、2和8 mg/L的营养液中暴露7 d,测定了根、茎、叶中镉、非蛋白巯基(NPT)、半胱氨酸(Cys)、γ-谷氨酰半胱氨酸(γ-EC)、谷胱甘肽(GSH)和植物络合素(PCs)的含量。植物根、茎、叶中镉含量都随着镉暴露浓度的增加而增加。当溶液中镉浓度较低(0.1～2 mg/L)时,茎叶中NPT、PCs、Cys和γ-EC含量随着镉浓度增加而增大;当镉浓度较高(8 mg/L)时,茎叶中PCs含量迅速降低,GSH含量大幅度增高。在根部,这些巯基化合物的含量几乎不受镉处理影响,且含量较低。以上研究结果表明:PCs在万寿菊镉的解毒机制中发挥一定的作用,暴露于高浓度的镉,GSH比PCs起着更为重要的解毒作用。     

Effects of nickel chloride and oxygen depletion on behaviour and vitality of zebrafish (Danio rerio, Hamilton, 1822) (Pisces, Cypriniformes) embryos and larvae

We examined acute (2 h exposure of 5-day-old larvae) and subchronic (exposure from fertilization up to an age of 11 days) effects of NiCl(2).6H2O on embryos and larvae of zebrafish (Danio rerio), both alone and in combination with oxygen depletion. The following endpoints were recorded: acute exposure: locomotory activity and survival; subchronic exposure: hatching rate, deformations, locomotory activity (at 5, 8 and 11 days) and mortality. In acute exposures nickel chloride (7.5-15 mg Ni/L) caused decreasing locomotory activity. Oxygen depletion (or=10 mg Ni/L resulted in delayed hatching at an age of 96 h, in decreased locomotory activity at an age of 5 days, and increased mortality at an age of 11 days (LC20=9.5 mg Ni/L). The observed LOEC for locomotory activity (7.5 mg Ni/L) is in the range of environmentally relevant concentrations. Since locomotory activity was already affected by acute exposure, this parameter is recommended to supplement commonly recorded endpoints of toxicity.     

Herbicide effects on typha latifolia (Linneaus) germination and root and shoot development

Aqueous 7-d germination and growth experiments were performed to compare responses of T. latifolia to exposures of atrazine (2-chloro-4-ethylamino-6-isopropylamine-s-atrazine) and paraquat dichloride (1,1′-dimethyl-4,4′-bipyridinium dichloride). T. latifolia seed germination was < 50 % in concentrations ≥ 1.0 mg/L of paraquat dichloride. No observed effect concentration (NOEC) and lowest observed effect concentration (LOEC) for paraquat and root growth were 0.001 and 0.01 mg/L, respectively, while NOEC and LOEC for paraquat and shoot growth were 0.01 and 0.1 mg/L, respectively following 7-d exposures. Greater than 72 % of seeds germinated in each concentration up to 30 mg/L atrazine. After 7-d exposure, NOEC and LOEC for atrazine and root growth were 0.1 and 1.0 mg/L, while atrazine and shoot growth NOEC and LOEC values were 15 and 30 mg/L, respectively. This research provides data concerning relative sensitivity of T. latifolia seedlings to the herbicides atrazine and paraquat, as well as the potential use of T. latifolia as a representative plant test species.     

Effect of two major N-nitroso hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) metabolites on earthworm reproductive success

Soil and topical tests were employed to investigate the effect of two N-nitroso metabolites of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) on earthworm reproduction. The lowest observed effect concentration (LOEC) for cocoon production and hatching was 50mg/kg for both hexahydro-1-nitroso-3,5-dinitro-1,3,5-triazine (MNX) and hexahydro-1,3,5-trinitroso-1,3,5-triazine (TNX) in soil. MNX and TNX also significantly affected cocoon hatching in soil (p<0.001) and in topical tests (p=0.001). The LOECs for cocoon hatching were 1 and 10mg/kg for MNX and TNX in soil, respectively, and 10mg/L in the topical test. Greater than 100mg/kg MNX and TNX completely inhibited cocoon hatching. In soil, the EC20 values for MNX were 8.7 and 8.8mg/kg for cocoon and juvenile production, respectively, compared to 9.2 and 9.1mg/kg for TNX, respectively. The EC20 values for the total number of cocoon hatchlings were 3.1 and 4.7mg/kg for MNX and TNX, respectively, in soil and 4.5 and 3.1mg/L in the topical test. Both MNX and TNX inhibited cocoon production and hatching, suggesting that they may have a negative affect on soil ecosystems at contaminated sites.     

Development of an in vitro toxicological test system based on zebrafish (<Emphasis Type="Italic">Danio rerio</Emphasis>) sperm analysis

The effect of seven heavy metals on the motility parameter of zebrafish sperm was tested in order to develop an in vitro toxicological test system as an alternative to live animal testing. In vitro test systems are currently preferred in ecotoxicology due to their practical and ethical advantages and fish sperm can be a suitable model. A number of studies had been carried out previously on this topic, but the described methods had not been standardized in numerous aspects (donor species, measured endpoint, etc.). In this study, heavy metals (mercury, arsenic, chromium, zinc, nickel, copper, cadmium) were used as reference toxicants with known toxicity to develop a standardized fish sperm in vitro assay. The tested concentrations were determined based on preliminary range finding tests. The endpoints were progressive motility (PMOT, %), curvilinear velocity (VCL, μm/s), and linearity (LIN, %) measured by a computer-assisted sperm analysis (CASA) system. According to our results, PMOT was the most sensitive of the three investigated parameters: dose-response curves were observed for each metal at relatively low concentrations. VCL values were less sensitive: higher concentrations were needed to observe changes. Of the three parameters, LIN was the least affected: dose-response relationship was observed only in the case of mercury (e.g., lowest observed effect concentration (LOEC) of Hg at 120 min: 1 mg/L for PMOT, 2.5 mg/L for VCL, 5 mg/L for LIN; LOEC of Cu at 120 min: 1 mg/L for PMOT, 5 mg/L for VCL, any for LIN). The order of toxicity as determined by PMOT was as follows: Hg²⁺?>?As³⁺?>?Cd²⁺?>?Cu²⁺?>?Zn²⁺?>?Cr³⁺?>?Ni²⁺. In conclusion, we found that PMOT of zebrafish sperm was an accurate and fast bioindicator of heavy metal load. Sperm analysis can be adopted to estimate the possible toxic effects of various chemicals in vitro. Future investigations should concentrate on the applicability of this assay to other contaminants (e.g., organic pollutants).     

Acute effects of diclofenac and DMSO to Daphnia magna: immobilisation and hsp70-induction

To determine the toxicity of the anti-rheumatic drug diclofenac to Daphnia magna, acute toxicity tests according to the OECD guideline 202 were combined with biochemical investigations of the hsp70 level as a biomarker for proteotoxicity. Particular attention was paid to the impact of the solvent DMSO as a confounding factor to diclofenac toxicity by means of testing different variations of producing stock solutions. In the acute immobilisation tests, diclofenac was most toxic as a singular test substance, with indication of a slight antagonistic interaction between the two substances. The highest EC(50) values were obtained in those approaches using diclofenac pre-dissolved in DMSO. Thus, the observed antagonism seems to be intensified by pre-dissolution. Hsp70 levels of 12- to 19-days-old D. magna were determined after 48h exposure using a highly reproducible immunological protocol. Hsp70 induction occurred at a LOEC of 30mgl(-1) diclofenac plus 0.6mll(-1) DMSO, and at a LOEC of 40mgl(-1) for diclofenac alone. In summary, DMSO showed only slight confounding effects on diclofenac action in the applied range of concentrations.     

Toxic effects of 2,4‐D herbicide on fish

Abstract

Acute and subacute 2,4‐D toxicity to carp (Cyprinus carpio L.) were investigated. Acute toxicity (LC‐ 50) was investigated in semi‐static test during a 24, 48, and 96‐ hours exposition. Subacute toxicity was investigated by exposing fish to different 2,4,‐D concentrations (150, 200, and 250 mg/L) for 14 days. Biochemical and morphological changes in certain organs and tissues were investigated.

LC‐ 50 values at 24 hours exposure was 310.0 mg/L, 295.0 mg/L for 48 hours, and 270.0 mg/L for 96 hours exposure.

Subacute toxicity tests show that 2,4‐D induce changes in the enzyme activities (AP, GOT, GPT) and morphological changes in the gills, liver and kidneys, but changes are of limited biological importance.     

Toxicity of copper in an oxic stream sediment receiving aquaculture effluent.

Sediments were collected from a stream (upstream, outfall and downstream) receiving copper laden catfish pond effluent to assess toxicity to non-target biota. No significant reduction in Hyalella azteca survival or growth (10 d), or Typha latifolia germination and root and shoot growth (7 d) were observed after exposure to upstream and outfall sediments. A significant reduction in H. azteca survival was observed after exposure to the downstream sediment sample; however, no reduction in T. latifolia germination or seedling growth was detected. Bulk sediment copper concentrations in the upstream, outfall and downstream samples were 29, 31, and 25 mg Cu/kg dry weight, respectively. Interstitial water (IW) concentrations ranged from 0.053 to 0.14 mg Cu/l with 10 d IW toxicity units > or = 0.7. Outfall samples were amended with additional concentrations of copper sulfate so that bulk sediment measured concentrations in the amended samples were 172, 663, 1245, and 1515 mg Cu/kg dry weight. Survival was the most sensitive endpoint examined with respect to H. azteca with a no observed effects concentration (NOEC) and lowest observed effects concentration (LOEC) of 1245 and 1515 mg Cu/kg, respectively. NOEC and LOEC for T. latifolia root growth were 663 and 1245 mg Cu/kg, respectively. IW copper concentrations were > or = 0.86 mg Cu/l with H. azteca intersitial water toxicity unit (IWTU) concentrations > or = 1.2. Sequential extraction qualitatively revealed the carbonate and iron oxide fractions which accounted for a majority of the copper binding. In this instance, the copper which was applied to catfish ponds does not appear to be adversely impacting the receiving stream system.     

新生MnO2对水中酸性媒介深黄GG的吸附脱色作用

以化学法合成的新生MnO2作吸附，对水中酸性媒介深黄GG进行吸附脱色研究，探讨了影响吸附的因素，结果表明，该吸附剂在PH1．5以下，投加量为0.3mg/L，温度为15℃条件下，饱和吸附量达1320mg/g，脱色率达96％以上，具有很高的吸附脱色能力。PH值是能力吸附能力的关键因素，温度，染料浓度和MnO2投加量影响程度较小。     

Sm-Gly-VB6对Pb-Cd胁迫下五种树木若干生理生化指标的影响

采用叶圆片法研究了模拟 Pb- Cd胁迫污染对 5种树木若干生理生化指标的影响。结果表明 ,Pb- Cd胁迫 ( Pb70 0 m g·L-1 ,Cd2 0 m g/ L)使 5种树木的叶绿素含量、质膜透性、过氧化氢酶活性、叶片内 Pb和 Cd的富集量均产生明显变化。经 Sm- G ly-VB6处理的 5种树木 ,上述各项指标的变幅明显减小 ,说明 Sm- G ly- VB6对重金属伤害植物有一定的缓解作用     

Fenton试剂处理电厂离子交换树脂再生废水

采用 Fenton试剂对电厂离子交换树脂再生废水进行催化氧化处理 ,实验结果表明 ,当溶液 p H=2 .0、H2 O2 ( 30 % )投加量为 6 0 m L/L、F e SO4· 7H2 O投加量为 4.5 g/L、H2 O2 投加次数为 4、反应时间为 1.5 h时 ,废水的处理效果最佳