沉淀物和生物中U,Th和226Ra的联合测定

用放射化学法对U,Th,~(226)Ra等核素进行联合测定,国外已有不少报道,只是所用的分离方法和所测的介质不同而已。我国学者也做过一些这方面的工作。本工作建立了用三正辛胺-二甲苯萃取分离法对沉积物和生物样中U,Th和~(226)Ra的联合测定方法。 二、主要仪器与试剂     

Study of prediction for groundwater contamination in wastewater land treatment system

This paper uses a prediction model of groundwater pollution based on the experiments in the laboratory and in field .The model, which was tested and calibrated by the field observated data ,satisfactorily simulated the field conditions in land treatment system of wastewater . Particularly , the model can provide the reliable pollution prediction of heavy metals , organisms and nitrogen . The model was used to predict the groundwater pollution caused by the land treatment system in the region of North China . The calibration of the model showed that correlation coefficients between the tested and predictive data of Cr6+. As3+, organism and NH4+ could reach 0.990, which proved that the model possessed the realistic instructive significance for design and use of wastewater land treatment systems .     

莫桑比克的海洋生物学研究:过去、现在及未来

本文概述了莫桑比克包括渔业在内的海洋生物学研究的发展情况.莫桑比克的海岸线约为3000km,海洋的生物资源在莫桑比克的社会中起着重要的作用,主要是作为人们的蛋白质来源以及收入和出口创汇的来源.     

不同生物接触氧化方法对藻类的去除效果比较及其途径分析

比较了3种生物接触氧化法对富营养化水源水中藻类的去除效果，探讨其去除藻类的途径。试验结果表明：淹没式曝气生物陶粒滤池（I型）在4-6m/h过滤速度条件下，对藻类总数的去除效率稳定，平均为70%左右；采用YDT弹性立体填料的中心导流筒曝气生物接触氧化法（Ⅱ型）与直接微孔曝气生物接触氧化法（Ⅲ型），在试验初期对藻类总数的去除率较低，平均去除率分别为60.2%、51.6%。但随着生物膜厚度的增加，试验后期对藻类的去除效果逐步得到提高，平均达70%以上。生物膜对藻类的生物絮凝、吸附、生物膜的脱落沉降等是生物接触氧化法去除藻类的主要途径。     

Combined effect of tributyltin and benzo[a] pyrene on the levels of sex hormone and vitellogenin in female Sebastiscus marmoratus

Tributyltin（TBT）, an organometal used as an antifouling biocide, has been reported to induce masculinization of fish. Benzo [a]pyrene （BaP）, a widespread carcinogenic polycyclic aromatic hydrocarbon, has been reported that its microsomal metabolites can produce an estrogenic response when tested in vitro. This study was therefore designed to examine the potential in vivo influence of TBT, BaP and their mixture on sex hormone levels in serum of Sebastiscus marmoratus, which were given 2 separate intraperitoneally （ip） injections（a single injection every 7 d） of TBT（0.5, 1, 5 and 10 mg/kg）, BaP（0.5, 1, 5 and 10 mg/kg）, or both in combination（0.5, 1, 5 and 10 mg/kg）; control fish received olive oil vehicle only. Six days after the 2nd injection, serum samples were collected and analyzed for sex hormone levels and alkali labile protein phosphorus （ALPP）, which is related to the yolk precursor protein vitellogenin. The pollutants at all doses significantly reduced serum testosterone, estradiol and ALPP content after 2 injections compared with the corresponding controls. The reduction of the estradiol levels should be response for the decrease of the vitellogenin levels. The results in the present study suggested that aromatase seems not the major target acted by TBT and BaP in fish. This study demonstrated that TBT or BaP exposure both inhibit the reproductive potential in female Sebastiscus marmoratus. Combined effect of TBT and BaP on the serum testosterone, estradiol and ALPP was not antagonism from the anticipation.     

水稻烤田期间N2O排放及其影响因素

水稻田间实验研究了烤田期间的土壤温度、Eh、含水量和裂缝基本性质,矿质态氮以及与氮有关的酶活性的演变规律,及其对N2O排放的影响.试验表明,在水稻分蘖期间烤田,N2O有一个排放高峰,其最高值可达75.6μg·m-2·h-1.在排放高峰后,即使继续烤田,N2O的排放值也将降低.N2O排放与尿素氮肥的施用量没有明显关系.裂缝的生成,改变了N2O的日排放规律.随着烤田时间的延长,脲酶和羟胺还原酶活性呈波动变化,硝酸还原酶活性递减,亚硝酸还原酶活性极低.硝酸还原酶活性与N2O排放之间没有显著相关性.土壤中的脲酶活性与N2O日排放通量呈显著的线性正相关.在烤田期间,NO-3含量呈增加趋势.土壤中的硝态氮含量与N2O排放通量之间呈显著正线性关系.土壤中的铵态氮含量与N2O排放通量之间呈显著负线性相关.     

On-line optical determination of floc size of Fe(Ⅲ) coagulants

This study investigated the floc aggregation, average floc size, floc size variance and floc growth velocity when ferric chloride （FeCl3） and polyferric chloride （PFC） were used to treat the simulated water samples. The factors including coagulant dose, ionic strength and solution pH, which affect the floc aggregation, were studied. Experiments were carried out in a bench-scale reactor using photometric dispersion analyzer （ PDA）. Results showed that there were great differences between the floc aggregation of PFC and FeCl3. The average floc size and fioc growth velocity of PFC were much larger than those of FeCl3. Compared with FeCl3, PFC gave a better coagulation performance in wider range of pH, dosage and ionic strength. It was also found that the coagulation efficiency of PFC did not depend on average floc size but on floc growth velocity.     

Sorption of pyrene on two paddy soils and their particle-size fractions

In the present study, the sorption of pyrene on two kinds of bulk paddy soils, Gleyic Stagnic Anthrosols, and Ferric accumulic Stagnic Anthrosols as well as their particle-size fractions was investigated. The sorption isotherms fitted well with Freundlich equation. For both soils, the clay fraction（ 〈 2μm） and coarse sand fraction（2000-250μm） had higher sorption capacity than fine sand fraction（250-20 μm） and silt fraction（20-2 μm）. The IogKoc values obtained of each soil and its particle-size fractions were similar, proving that SOM content was a key factor affecting pyrene sorption. The Kd values showed a significant correlation with contents of dithionite-extractable Fe in both paddy soils and a good relationship with CEC in Gleyic Stagnic Anthrosols, indicating possible effects of surface properties of particle-size fractions on the sorption of pyrene.     

托盘式烟气脱硫喷淋塔空塔冷态流场数值模拟

以600MW机组多孔合金托盘喷淋塔为研究对象,利用国际流行的商用CFD(ComputationalFluidDynamics)软件Fluent及其前处理软件Gambit对烟气脱硫立式喷淋空塔的流场进行二维数值模拟。计算中选用模型作为计算模型,用SIMPLE算法进行计算。计算结果表明,喷淋塔的烟气入口角度以及多孔合金托盘的安装高度对塔内流场分布有一定的影响,安装托盘后气速明显均匀化,斜切式烟气进口流场分布较直进式均匀,还获得了合适的托盘安装高度。     

采用钙钛矿型催化剂(La0.8K0.2Cu0.05Mn0.95O3)同时催化去除NOx和碳烟的研究

将钙钛矿型催化剂与碳烟均匀混合后置于固定床连续流动反应体系中,利用程序升温反应技术,在模拟柴油机尾气的情况下对同时催化去除氮氧化物(NOx)和碳烟的反应进行了实验研究.通过改变含Cu原料的用量,得到不同Cu取代量的催化剂La0.8K0.2CuxMn1-xO3,性能评价结果表明,La0.8K0.2Cu0.05Mn0.95O3催化剂的综合性能较好,碳烟的起燃温度及NO向N2的最大转化率分别为280℃和58.0%.采用该催化剂,进一步考察了进气中NO浓度、O2浓度、进气总流量及催化剂与碳烟的接触状况对反应的影响.研究结果表明,进气中NO浓度、O2浓度、气体总流量和催化剂与碳烟之间的接触状况对NO的去除率的影响比较明显,而对碳烟起燃温度的影响较小.O2浓度从5%变为7.5%时,碳烟的起燃温度及最大NO转化率分别从280℃和53.8%变为270℃和96.7%.碳烟与催化剂松散接触时,碳烟的起燃温度及最大NO转化率分别为290℃和48.4%,紧密接触时分别为275℃和70.4%.而进气中NO浓度、气体总流量的变化对碳烟的燃烧基本上没有影响,虽然NO的转化率有明显变化,但生成的N2总量基本不变.