FeAlOx/MMT催化Fenton反应降解高浓度苯酚废水

以蒙脱土为载体制备负载型Fe/Al复合氧化物(FeAlOx/MMT)用于催化Fenton反应降解高浓度苯酚废水。实验结果表明,活性相FeAlOx中Fe/Al摩尔比为0.22时制备所得催化剂对Fenton反应具有最佳活性,且Fe/Al复合氧化物并未嵌入蒙脱土层间。在低温和高pH条件下催化体系存在诱导期,诱导期内FeAlOx/MMT缓释出Fe离子并进而由Fe离子催化溶液中的Fenton反应。通过对非均相催化降解苯酚废水的动力学研究发现,H2O2初始浓度、溶液的pH和反应温度对COD降解效率具有显著影响。调节降解过程中的温度序列和氧化剂引入程序能够缓解高温和高双氧水浓度双重因素耦合导致的HO.自消耗。在优化的降解条件下使用理论用量的H2O2可使得1 g/L的苯酚废水中苯酚降解率达到100%,而COD的降解率则达到97%。     

Uptake and bioaccumulation of three PCBs by Chlorellafusca

This paper reports the bioaccumulation of three PCBs (2,4′-dichlorobiphenyl, 2,4,6,2′-tetrachlorobiphenyl and 2,4,6,2′,4′-pentachlorobiphenyl) by the green alga $\text{Chlorella}$$\text{fusca}$ under various conditions. A probable pattern of the bioconcentration mechanism is suggested. No metabolites were extracted from algae or water 6 days after incubation with PCBs.     

Toxicity of mixtures of phosphamidon and methidathion to lobsters (Homarusamericanus)

The joint toxicity of mixtures of phosphamidon and methidathion to adult lobsters ($\text{Homarus}$$\text{americanus}$) is greater than additive in tests with the combined 48-h toxicity unit of the mixtures totalling 0.25, 0.5 and 1.0 units. The largest magnification factor for greater than additive toxicity occurred where phosphamidon and methidathion contributed to the total toxicity unit in a ratio of 1:1.5 and was progressively smaller for ratios of 1:4.4 and 2:1.     

纳米Bi2O3/TiO2复合光催化剂的制备及性能研究

以光催化效果为评价标准,采用超声波作用下水解法制备Bi₂O₃/TiO₂复合光催化剂,考察了水解条件和Bi₂O₃掺入量等制备条件对复合光催化剂性能的影响。结果表明,与传统制备方法相比,该方法操作简单、快速;当水和乙醇的比例为4∶1时所得样品的光催化活性最好;Bi₂O₃的掺入拓宽了TiO₂对光的吸收范围,提高了TiO₂的光催化活性,掺入量(Bi₂O₃)为0.25%复合光催化剂催化活性最高;复合光催化剂对多种水溶性染料均具有较好的处理效果。     

Chemical transformation and flux of different forms of arsenic in the carb Carcinusmaenas

The amount of ingested arsenic assimilated and eliminated by the crab appeared to depend on chemical form of arsenic present in the food. Arsenic-74 was translocated rapidly with a high percentage located in hepatopancreas and exoskeleton. The speciation of radioarsenic determined by sequential extraction of experimental food, feces, muscle and hepatopancreas showed that there is no efficient mechanism within the crab which can covert lipid and water soluble arsenic to arsenite and residual arsenic or vice-versa. The biological mechanism in crab selectively and effectively excretes soluble form of arsenite and residual arsenic much more readily than organic arsenic.     

UV/H2O2工艺降解环丙沙星的研究

采用UV/₂O₂工艺去除水体中的喹诺酮类抗生素环丙沙星（CIP）。考察了溶液pH值、₂O₂投加量以及水体基质对环丙沙星降解效率的影响,分析了降解产物的生成情况。研究表明,环丙沙星的降解符合拟一级反应动力学模型。降解速率受溶液pH值的影响,酸性及中性条件,有利于环丙沙星的降解。₂O₂投加量的增大,使得降解速率逐渐增大,但速率增幅逐渐变缓;最佳₂O₂/环丙沙星摩尔比为2 000。实际水体中存在的NOM、NO^-₃,促进了单独UV作用下,环丙沙星的降解。水体中的?OH焠灭剂,抑制了UV/₂O₂联合作用下,环丙沙星的降解;实际水体中的光解速率常数低于超纯水中的光解速率常数。GC-MS分析表明,UV/₂O₂工艺,使环丙沙星氧化降解生成氨基乙酸、丙二酸、丙三醇和对苯二甲酸等小分子有机物。     

Partitioning of polychlorinated biphenyls in octanol/water, triolein/water, and membrane/water systems

The use of the octanol/water partition constant (Kow) as a surrogate parameter for lipid/water partitioning of persistent organic pollutants (POPs) was reassessed by comparing the measured Kow of 12 selected polychlorinated biphenyl congeners (PCBs) with partition constants in triolein/water (Ktw) and membrane/water (Kmw) systems. Kow and Ktw were measured by the slow-stirring method. Kmw was measured by an adaptation of the slow-stirring method using suspensions of phosphatidylcholine and phosphatidylserine liposomes. Partitioning of POPs to octanol, triolein, and liposomes is similar but not equal. The log-log correlation for Kow and Ktw is excellent (r2 = 0.982) and that for Kow and Kmw is somewhat weaker (r2 = 0.856). Ktw values are greater than Kow by a factor of 1.6. Kmw of some PCB congeners exceed both Kow and Ktw by an order of magnitude. The differences are attributed to different PCB activity coefficients in the different lipid phases. The results imply that Kow can be used as a reasonable conservative estimate of lipid/water partitioning. But the observed differences between Kow and Kmw also indicate that using Kow to predict accumulation of POPs, particularly highly hydrophobic ones, in the polar lipids of organisms will underestimate their concentrations at equilibrium.     

La_(1-x)Ce_xCu_yMn_(1-y)O_3/HZSM-5催化剂低温去除柴油机碳烟和NO_x

为实现对柴油机碳烟和NOx的低温同步去除,采用柠檬酸络合法制备分子筛负载钙钛矿型金属复合氧化物催化剂,应用X衍射分析仪(XRD)和电镜扫描仪(SEM)对催化剂性能进行表征,并在微型固定床反应器中对催化剂低温去除碳烟和NOx进行活性评价。利用程序升温反应(TPR)技术,进行催化剂活性评价、柴油机负荷和排放等特性实验。结果表明,A位用适量Ce部分取代La,B位用适量Cu部分取代Mn,可使碳颗粒燃烧温度降低,CO2选择性好,NOx转化率升高。La0.4Ce0.6Cu0.2Mn0.8O3/HZSM-5催化剂的最大NOx转化率为81.0%,Ti、Tm和Tf分别为250、350和475℃,表明该催化剂具有较好的催化活性,能在低温条件下去除碳烟和NOx。     

Accumulation of bis(tributyltin) oxide by the mud crab, Rhithropanopeusharrisii

Accumulation of ¹⁴C labelled bis(tributyltin) oxide (TBTO) by the mud crab, $\text{Rhithropanopeus}$$\text{harrisii}$, was determined through short-term exposure to labelled water and food. The potential for trophic accumulation during chronic low level exposure is emphasized.     

Synthesis of Cl2- to Cl4-diphenylsulfides and Cl1- to Cl3-dibenzothiophenes

The synthesis of eleven environmentally relevant mono-, di- and trichlorodibenzothiophenes (2) by photochemical ring-closure of polychlorodiphenylsulfides (1) is described. All monochlorodibenzothiophenes were additionally synthesized starting with a chlorothiophenol in a three-step reaction adapted from the synthesis of methyldibenzothiophenes.     

Toxicity of TiO2, ZrO2, Fe,Fe2O3, and Mn2O3 nanoparticles to the yeast, Saccharomyces cerevisiae

The growing application of engineered nanomaterials is leading to an increased occurrence of nanoparticles (NPs) in the environment. Thus, there is a need to better understand their potential impact on the environment. This study evaluated the toxicity of nanosized TiO₂, ZrO₂, Fe⁰, Fe₂O₃, and Mn₂O₃ towards the yeast Saccharomyces cerevisiae based on O₂ consumption and cell membrane integrity. In addition, the state of dispersion of the nanoparticles in the bioassay medium was characterized.     

柱状V/AC催化剂的再生对脱硫活性的影响

使用常压固定床反应器,考察了吸附SO2的柱状V/AC催化剂的热再生和NH3再生行为.结果表明:柱状V/AC催化剂再生过程中生成的SO2主要沿催化剂轴向由内部向外扩散.催化剂350 ℃NH3再生的效率高于热再生的效率.两次热再生后柱状V/AC催化剂的脱硫活性开始下降,而六次NH3再生后的脱硫活性仍保持不变,甚至还稍高于新鲜柱状V/AC催化剂的脱硫活性.柱状V/AC催化剂孔结构和元素分析结果表明,NH3再生使催化剂表面含N官能团增加,保护了催化剂小于1 nm的微孔.     

Environmentally-induced cadmium tolerance in the grass Holcuslanatus L.

This paper reports results of a study on cadmium tolerance in the grass $\text{Holcus}$$\text{lanatus}$ which suggest that tolerance is inducible and can be lost in transplanting plants to uncontaminated soils.     

UV/H_2O_2/TiO_2联合水解酸化+MBR工艺处理亚砜废水

二甲基亚砜(DMSO)废水因其COD高、可生化性差的特性而较难处理。本实验以采用硫酸二甲酯法生产DMSO的某化工厂废水为研究对象,设计并建立了组合式光催化氧化装置联合水解酸化+MBR工艺的中试系统,探讨了组合式光催化氧化装置、氧化剂投加量、pH、反应时间和水力停留时间对系统处理效果的影响。结果表明,组合式光催化氧化装置可有效提高DMSO废水的可生化性。最优工艺参数为:按H2O2与原水COD质量浓度比为2∶1投加H2O2,在pH值为4、反应时间为6 h、水力停留时间为4 h的条件下,该系统对原水COD(5 000 mg/L)去除率大于98%,出水COD达到《污水综合排放标准》(GB 8978-1996)一级要求。     

区域大气环境中PM2.5/PM10空间分布研究

提出了一种利用移动监测技术研究区域大气环境中PM_2.5/PM₁₀空间分布的方法,并在2004年12月进行了宁波市全市域PM_2.5/PM₁₀空间分布的研究。数据显示：相同路径所代表的地区PM_2.5和PM₁₀具有很好的相关性,多数路径上PM_2.5与PM₁₀数据的相关系数平方在0.95以上,而不同路径上PM_2.5与PM₁₀的比值不同。文中给出了宁波市PM_2.5/PM₁₀污染的空间分布图,直观地显示出PM_2.5/PM₁₀污染的空间分布情况,突出了污染的重点点位和地区。     

改性TiO2光催化降解三苯甲烷类污染物

以硫酸钛为原料采用水热法制备了掺Fe3+TiO2晶体粉末,采用X射线衍射仪(XRD)对样品的结构进行了表征。在可见光条件下,用溴酚蓝、甲基绿、甲基蓝、孔雀石绿、甲基紫和碱性品红等6种典型三苯甲烷类化合物为目标降解物,研究了以自制的掺Fe3+TiO2晶体粉末对它们的催化降解作用。实验结果表明,制备的掺Fe3+TiO2晶体属于锐钛矿型。6种化合物的光催化降解反应遵循拟一级动力学规律,且可用Langmuir-Hinshelwood(L-H)动力学模型描述,其表观反应速度常数(k)的大小顺序为:溴酚蓝<甲基绿<甲基蓝<孔雀石绿<甲基紫<碱性品红,大小变化次序与其半衰期t1/2成反比,并从分子结构上对它们的降解规律进行定性解释。     

The loss (in field and under laboratory conditions) of 65Zn by the postlarval rudd, Scardiniuserythrophthalmus L.

The loss of ⁶⁵Zn by postlarval rudd was followed in the laboratory and in the field experiments. It is concluded that the results obtained in the field and the laboratory cannot be comparable in the postlarval stage of the rudd fish.     

US/Zn~0体系降解水中的对硝基苯甲酸

为高效去除水体中的对硝基苯甲酸、开发新型水处理技术,提出以超声与单质锌联用降解水中的对硝基苯甲酸。考察了锌投加量、溶液初始pH、声功率及溶液初始浓度对拟一级反应速率常数(k0US/Zn)的影响,比较了US、Zn0和US/Zn03体系下的降解常数,并对US/Zn0体系的降解机理进行了初探。结果表明,以上4种因素对k0US/Zn均有很大影响,k0US/Zn分别在溶液初始pH为5、声功率为120 W、溶液初始浓度为0.04 mmol/L时达到最大值,且随着锌投加量的增加而增加。超声与单质锌在降解对硝基苯甲酸的过程中存在很好的协同作用,在最优条件下,k0US/Zn=0.052 min-1,分别是单独超声降解及单独锌降解的21.5倍和2.53倍。在联用体系中,主要是依靠OH·氧化及单质锌还原的相互加强来去除对硝基苯甲酸。     

UV/H2O2/Fe-FeOxH2x-3和UV/H2O2工艺降解水中富里酸的研究

采用硼氢化钠还原法制备核-壳结构的Fe-FeO_xH_2x-3复合材料，研究了富里酸在UV/H₂O₂和UV/H₂O₂/Fe-FeO_xH_2x-3两种不同反应体系下的降解情况。结果表明，核-壳结构Fe-FeO_xH_2x-3的存在，提高了UV/H₂O₂降解富里酸的反应速率，TOC去除达到84%。采用XAD树脂吸附法对反应前后的富里酸进行化学分级表征，结果表明，富里酸经反应后憎水酸（HoA）、弱憎水酸（WHoA）和憎水中性物质（HoN）都有所减少，进而转化为亲水性物质（HiM）；用超滤膜法对富里酸进行物理分级表征，考察了富里酸在反应前后分子量分布的变化情况。同时，富里酸经过反应后生成的中间产物降低了三氯甲烷生成趋势。     

Application of GC-MS/MS for the analysis of PCDD/Fs in sewage effluents

The application of high resolution gas chromatography in combination with tandem mass spectrometry in an ion trap was tested to substitute the expensive high resolution mass spectrometry in analysing polychlorinated dibenzo-p-dioxins and furans in sewage effluents. In tandem mass spectrometry, a set of parameters has to be optimised in order to attain the required sensitivity. To the best of our knowledge, this is the first time a method development for analysing PCDD/Fs with GC-MS/MS in an ion trap is described in this detail. Nine parameters are varied, including isolation window, collision induced dissociation (CID) amplitude, CID time, acquisition mass range, broadband amplitude, CID bandwidth, modulation range, filament current and ion trap temperature. This technique can be adapted to other analytes. By this optimisation, limits of detection of 0.01-0.05 ng/l are obtained. With its selectivity and sensitivity, tandem mass spectrometry is a powerful tool for the determination of PCDD/Fs in water samples. 55 sewage effluent samples from Germany were analysed.