Cu~(2+)、Zn~(2+)对黑褐新糠虾(Neomysis awatschensis)的毒性作用

通过在基础海水中添加Cu2 、Zn2 ,研究其对黑褐新糠虾(Neomysis awatschensis)的急、慢性毒性影响.包括了Cu2 、Zn2 对黑褐新糠虾在24、48、72和96 h的半致死浓度(LC50),安全浓度(SC)和在生长、成活、繁殖等方面的影响.结果表明:(1)水体中Cu2 对黑褐新糠虾24、48、72和96 h LC50和SC分别是2843、2363、1432、449 μg/L和4.49 μg/L.Zn2 对黑褐新糠虾24、48、72和96 h LC50和SC分别是10588、2331、1459、664 μg/L和6.64 μg/L.Cu2 对黑褐新糠虾的毒性大,黑褐新糠虾对Cu2 比对Zn2 更为敏感.(2)当5 μg/L≤Cu2 ≤80 μg/L、10 μg/L≤Zn2 ≤160 μg/L时,黑褐新糠虾在处于各浓度的Cu2 、Zn2 试液中经过60d的饲养,均显示一定程度的毒性作用,其成活率、体长和体长增长率随Cu2 、Zn2 浓度的不断增加都有不同程度的降低,与对照组相比均差异显著(P﹤0.05).     

未来50年鄱阳湖流域气候变化预估

据 ECHAM5/ MPI OM模式在3种排放情景（SRES高排放A2,中排放A1B,低排放B1）下所做的21世纪前50年气候变化预估试验得到的数据,研究鄱阳湖流域2001~2050年气温和降水相对于目前气候（1961~1990年）的可能变化。结果表明：①未来50年气温在3种排放情景下都将迅速增加,远远高于1990s的增加幅度和速度。A1B情景温度增加最明显,平均气温变化达到162°C。②降水量变化相对复杂,前30年主要为减少趋势,A2情景下减少幅度最大,2020s年均降水量减少了67%;后20年降水量增加,B1情景增加最显著,2030s年增加幅度达到108%。③根据预估的各季节变化结果,1~3月和 4~6月降水量增加;而降水减少主要在7~9月和10~12月,则赣江流域类似于2003~2005年的伏旱、秋旱连冬旱的情况将可能阶段性出现,并在2011~2030年加强。④降水量的空间分异非常明显,东部变化大于西部,南部变化大于北部。⑤如果2001~2050年在A2或A1B情景下,降水序列存在20a的周期振荡;在B1情景下,存在30a的周期振荡。人类排放增加可能弱化振荡强度,并使周期发生变化。     

三苯基锡对紫萍生长及酶活性的毒性作用

以紫萍作为实验生物,通过研究不同浓度的三苯基锡对紫萍（Spirodela polyrrhiza L．）根叶生长、多酚氧化酶（PPO）活性、过氧化氢酶（CAT）活性和过氧化物酶（POD）的影响,为及时发现和排除三苯基锡的污染提供理论和直观依据。结论表明：培养4d后,三苯基锡处理对紫萍叶片生长量的IC50为0．71mg／L。相同培养液条件下,PPO、CAT和POD均随着三苯基锡处理浓度的升高呈现先升高后下降的趋势。从中可以说明三苯基锡对紫萍有明显的毒性作用。     

SO_2体积分数对ZL50活性炭吸附脱硫行为的影响和动力学分析

通过动态吸附烟气脱硫实验,考察了烟气中不同SO2体积分数对ZL50脱硫脱硝活性炭脱硫行为的影响,并进行了动力学分析.随着烟气中SO2体积分数增大,脱硫率和ZL50脱硫脱硝活性炭的活性度下降;SO2吸附量和吸附速率增大.模拟结果表明,Bangham模型模拟效果最优,SO2的催化氧化反应对化学吸附有重要影响;Lagergren准一级吸附速率常数随SO2进口体积分数的增加而增大,表明SO2的催化氧化反应在吸附前期可能为速控步骤.推导和定义了Lagergren模型和Bangham模型的初始吸附速率;推导了文献上的Ho模型和Elovich模型的初始速率式。定义的Bangham初始吸附速率与初始吸附速率实验值吻合最好;建立的Bangham吸附反应动力学模型能较好地描述SO2动态吸附速率.结果表明,SO2的初始反应速率分级数为1或接近1,而O2和水蒸气的初始速率分级数分别为0.15～0.20和0.45～0.50之间的常数.     

Determination of haloacetic acids in hospital e uent after chlorination by ion chromatography

The ion chromatography combined solid phase extraction （SPE） method was developed for the analysis of low concentration haloacetic acids （HAAs）, a class of disinfection by-products formed from chlorination of hospital wastewater. The monitored HAAs included monochloroacetic acid, monobromoacetic acid, dichloroacetic acid, dibromoacetic acid and trichloroacetic acid. The method employed a sodium hydroxide eluent at a flow rate of 0.8 ml/min, electrolytically generated gradients, and suppressed conductivity detection. To analyze the HAAs in real hospital wastewater samples, C18 pretreatment cartridge was utilized to reduce samples＇ turbidity. Preconcentration with SPE and matrix elimination with treatment cartridges were investigated and found to be able to obtain acceptable detection limits. Linearity, repeatability and detection limits of the above method were evaluated. The detection limits of monobromoacetic acid and dibromoacetic acid were 2.61 μg/L and 1.30 μg/L, respectively, and the other three acids are ranging from 0.48 to 0.82μg/L under 25-fold preconcentration. When the above optimization procedure was applied to three hospital wastewater samples with different treatment processes in Tianjin, it was found that the dichloroacetic acid was the major compound, and the growth ratios of the HAAs after disinfection by sodium hypochlorite were 91.28%, 63.61% and 79.50%, respectively.     

预处理-IC-氧化沟-气浮工艺处理再生纸废水

介绍了预处理-IC-氧化沟-气浮工艺在再生纸废水处理工程中的应用。工程运行结果表明:该系统处理效果好、性能稳定、维护管理方便,出水pH为7.39～7.52,COD为57.6～58.7 mg/L,BOD5为12.5～15.8 mg/L,SS为18～19 mg/L,出水水质达GB3544—2008《制浆造纸工业水污染物排放标准》表1标准;通过制浆回收和废水再生循环利用,降低了运行成本;对同类型造纸废水的治理有一定的借鉴意义。     

IC反应器处理罗汉果加工废液的启动研究

试验研究了IC反应器处理罗汉果加工废液的启动特性以及效果,并考察了启动过程中反应器的产气性能和菌群形态。结果表明,在保持进水量不变,逐步增加进水浓度以提高有机负荷的情况下,仅40d反应器便完成启动,此时,IC反应器的COD有机负荷达7.586kg/(m3·d),COD去除率达95.6%,反应器产气量可达20.9L/d,产气率达89.9%,其中甲烷含量高达74.6%。启动成功后,形成具有一定机械强度、密实且沉降性能良好的颗粒物污泥。颗粒污泥呈深灰色,粒径约为0.5～3.5mm。颗粒污泥中以球菌和链状杆菌占优势。     

铜和镉对珠江天然仔鱼和幼鱼的毒性效应及其潜在生态风险

以静水实验法探讨珠江流域主要金属污染物铜和镉对当地天然仔鱼和幼鱼的急性毒性效应。结果显示,铜对西江赤眼鳟和鲴仔鱼(48 h)和广东鲂幼鱼(96 h)的LC50分别为0.066、0.055和0.10 mg·L-1,对应的安全浓度分别为0.006、0.010和0.010 mg·L-1;镉对赤眼鳟和鲴仔鱼(48 h)以及广东鲂幼鱼(96 h)的LC50分别为1.29、0.83和3.20 mg·L-1,对应的安全浓度分别为0.163、0.077和0.320 mg·L-1。其中,铜对上述受试鱼的安全浓度低于或接近我国《渔业水质标准》及《地表水环境质量标准》Ⅱ类水对铜的规定,而镉对这些受试鱼的安全浓度则高于相关标准对镉的规定。研究结果表明,珠江流域铜污染可能会对当地天然仔鱼、幼鱼群体的补充构成一定程度的威胁,但镉污染暂不会对该区域主要鱼类早期群体补充带来严重的生态风险。     

Comparative effects of indole derivatives as antifouling agents on the growth of two marine diatom species

Antifouling agents, used to prevent biofouling, need to be assessed for their impacts on marine organisms and environment before the application. Diatoms are one of the main components of fouling biofilms, which play important roles in the formation of biofouling. Particularly, diatoms are also the important ingredients of primary production and present interest as ecotoxicological models in marine environment. In this study, two benthic diatoms Nitzschia closterium f. minutissima and Navicula climacospheniae, widely distributed in fouling biofilm, were used as models for screening the activities of potential antifoulants. Nine indole derivatives were tested and CuSO₄ was used as a reference. Indole derivatives showed significant anti-algal activities and the EC₅₀ values of most indole derivatives were lower than that of CuSO₄. Halogen substituent enhanced the anti-algal activities of compounds, and the most efficient compounds for N. closterium f. minutissima were gramine and 7-chloroindole with the EC₅₀ values of 1.94 and 2.1?mg/L, while for N. climacospheniae, 7-chloroindole and 6-bromoindole were the most efficient and the EC₅₀ values were 3.91 and 4.25?mg/L, respectively. In conclusion, indole derivatives would be one of the promising candidates as antifoulants and our results strengthened the need to perform antifouling activity assays and environment-friendly evaluations.     

Cardioprotective effect of Lagenaria siceraria (Mol) ameliorates isoproterenol-induced cardiac toxicity in rats by stabilizing cardiac mitochondrial and lysosomal enzymes

A study was conducted to determine the effect of the chironomid larval tube on heavy metal toxicity. Silica gel was provided as a substrate with which the chironomid larvae could construct larval tubes. A series of 96 h LC₅₀ bioassays were conducted with and without the presence of the silica gel substrate, to allow comparison between the two test conditions. From the study it was observed that a 10–15% variation in LC₅₀ value occurred. The 96 h LC₅₀ for copper at the temperatures 35, 28, 20, 15, and 10°C was observed to be 7.5, 9.5, 7.5, 4.5, 3.6, and 2.8 mg L^?1, respectively. The same test when conducted in the presence of silica gel produced LC₅₀ values of 26.50, 33.50, 15.82, 12.77, and 9.94 mg L^?1 for the same temperatures. This would demonstrate that the larval tube did, to some extent, protect the larvae from the effects of the heavy metal.