高效喷淋泡沫脱硫技术及装置的应用

SO2是产生酸雨的主要气体，其主要来源于工业燃煤锅炉。以沈阳一家电厂为例，该厂选用新型高效的喷淋泡沫脱硫除尘器对锅炉排放的SO2进行治理。进入喷淋泡沫塔前的SO2平均浓度为2780mg／m^3，经脱硫后出塔平均浓度为289．3mg／m^3，去除率为89．6％。结果表明，这种有别于传统湿法的新型高效的喷淋泡沫脱硫技术及装置具有脱硫效率高、装置占地少、运行稳定、沉淀物易于回收利用等特点，对锅炉排放的SO2进行治理是非常有效的。     

Quantitative structure-activity relationships for the inhibition toxicity to root elongation of Cucumis sativus of selected phenols and interspecies correlation with Tetrahymena pyriformis

The comparative toxicities of selected phenols to higher plants Cucumis sativus were measured and the negative logarithm molar concentration of the root elongation median inhibition (IRC50) were derived. Quantitative structure-activity relationships (QSARs) were developed to explore the toxicity influencing factors and for predictive purpose. The toxicity data, fell into two classes: polar narcosis and bio-reactive. For polar narcotic phenols, a highly significant two-parameter QSAR based on 1-octanol/water partition coefficient (logKow) and energy of the lowest unoccupied orbital (E(lumo)) was derived (IRC50 = 0.77 log Kow - 0.39E(lumo) + 2.36 n = 22 r2 = 0.89). The five bio-reactive chemicals proved to show elevated toxicity due to their typical substructure involved diverse reactive mechanisms. In an effort to model all chemicals, a robust multiple-variable QSAR combining logKow, E(lumo) and Qmax, the most negative net atomic charge, was developed (IRC50 = 0.65 logKow - 0.72E(lumo) + 0.23Qmax + 2.81 n = 27 r2 = 0.94), indicating that hydrophobicity, electrophilicity and hydrogen bond interaction contribute mainly to the phytotoxicity. The toxicological data was compared with Tetrahymena pyriformis 2-d population growth inhibition toxicity (IGC50) and excellent interspecies correlations were observed both for the polar narcotics and for five reactive chemicals (for polar narcotics: IRC50 = 0.95IGC50 + 1.07 n = 16 r2 = 0.89; for bio-reactive chemicals: IRC50 = 0.98IGC50 + 2.19 n = 5 r2 = 0.97; and for all: IRC50 = 0.93IGC50 + 1.63 n = 21 r2 = 0.87). This suggested that T pyriformis toxicity could serve as a surrogate of C. sativus toxicity for phenols and interspecies correlation also could be established for reactive chemicals.     

Nitrous oxide emissions from tundra soil and snowpack in the maritime Antarctic

The nitrous oxide emissions were measured at three tundra sites and one snowpack on the Fildes Peninsula in the maritime Antarctic in the summertime of 2002. The average fluxes at two normal tundra sites were 1.1 ± 2.2 and 0.6 ± 1.7 μg N₂O m⁻² h⁻¹, respectively. The average flux from tundra soil site with penguin dropping addition was 3.7 ± 2.0 μg N₂O m⁻² h⁻¹, 3–6 times those from the normal tundra soils, suggesting that the deposition of fresh droppings enhanced N₂O emissions during penguin breeding period. The summer precipitation had an important effect on N₂O emissions; the flux decreased when heavy precipitation occurred. The diurnal cycle of the N₂O fluxes from Antarctic tundra soils was not obtained due to local fluky weather conditions. The N₂O fluxes through four snowpack sites were obtained by the vertical N₂O concentration gradient and their average fluxes were 0.94, 1.36, 0.81 and 0.85 μg N₂O m⁻² h⁻¹, respectively. The tundra soils under snowpack emitted N₂O in the maritime Antarctic and increased local atmospheric N₂O concentrations; therefore these fluxes could constitute an important part of the annual N₂O budget for Antarctic tundra ecosystem.     

等离子体协同光催化去除模拟烟气中SO2的实验研究

近年来,低温等离子体技术以及纳米TiO₂光催化技术在烟气脱硫中的应用越来越引起人们的关注。利用填充床反应器将这2种技术有机地结合起来，进行了大量脱硫实验研究。研究结果表明，等离子体协同光催化去除烟气中的SO₂与单独采用等离子体技术相比，其SO₂的去除率可提高5%～20%。同时，探讨了等离子体协同TiO₂光催化剂的脱硫机理，分别研究了外加电压、气体流量和SO₂初始浓度等因素对脱硫效率的影响。实验结果表明，当SO₂初始浓度为800 mg/m³，输入电压为17.5 kV，气体流量为0.2 m³/h时，SO₂脱除率可以达到77.6%。     

Sample purification for analysis of organochlorine pesticides in sediment and fish muscle

The methods of sample purification for determinations of organochlorine pesticides (OCPs) in sediment and fish muscle were investigated in this study. A two-step procedure with preliminary cleanup and florisil column fraction was adopted. The working conditions of florisil column were firstly optimized. As to preliminary cleanup, liquid-liquid extraction by mixture of dimethyl formamide (DMF) and hexane and sulphonation by concentrated sulfuric acid were applied respectively and compared for the studied samples. The results indicated that liquid-liquid distribution could effectively separate lipids from fish muscle extracts, while failed in elimination of chlorophyll extracted from the relicts of hydrophytes in the sediment sample. In view of the sample appearance and clarity of gas chromatogram, sulphonation was more suitable to purify the sediment sample, however, the recoveries of the spiked standards were poor. The use of eluting solvent with stronger polarity could improve the corresponding recoveries significantly. Due to complete loss of Dieldrin, Endrin, and Endrin aldehyde after sulphonation, this pretreatment was improper to the three components. Sulfur, as the particular disturbing element in sediment, could be removed sufficiently by addition of activated copper powder. The relevant detection limits of the selected methods for OCPs in the studied substrates were also provided.     

新型沸石填料间歇硝化反应器的研究

介绍一种新型沸石填料 ,用于提高生物脱氮系统中硝化反应器的硝化性能。试验结果表明 ,应用了沸石填料的硝化反应器的硝化性能得到了显著提高 ,在脱氮效率和速率上 ,与普通生物载体硝化反应器相比具有明显的优势。硝化反应器连续运行 17d ,出水氨氮基本在 1mg/L以下 ,氨氮去除率在 97%以上。该系统停止运行 5 0d后再次启动 ,一周内硝化性能得以恢复     

厌氧折流板反应器处理硝基苯废水的研究

采用厌氧折流板反应器(ABR)中温处理含硝基苯废水,研究了工艺条件和硝基苯的降解特点.试验结果表明:在进水COD浓度为2088 mg/L,硝基苯浓度为16.8 mg/L,反应温度为35℃,停留时间为24 h条件下,ABR能有效处理硝基苯废水,COD去除率为86.4%,硝基苯去除率为91.1%;在厌氧条件下,硝基苯降解为苯胺,但苯胺很难再进一步分解;硝基苯的去除历程推断为先吸附后分解.     

锶—89在珍珠岩中吸附的研究

研究了不同粒径的珍珠岩对＾８９Ｓｒ的吸附。结果表明，珍珠岩对＾８９Ｓｒ具有较强的吸附能力，饱和吸附率大于９５％；通过振荡能加速珍珠岩对＾８９Ｓｒ的吸附；珍珠岩对＾８９Ｓｒ的吸附率与时间关系由多项指数描述；不同粒径的珍珠岩对＾８９Ｓｒ的吸附率没有明显差异。     

粉末活性炭对膜过滤性能的影响

向一体式膜生物反应器中投加粉末活性炭(PAC),可以显著提高膜的过滤性能,有效缓解膜的污染.研究结果表明:投加PAC的吸附作用减少了由于胞外聚合物(EPS)而引起的膜污染;膜表面PAC颗粒的存在减小了浓差极化层的厚度和水力边界层的厚度,提高了过滤物质的传递速率;膜表面形成的PAC层还可过滤微生物和胶体颗粒,减少了它们到达膜表面的数量.     

淡水沉积物中重金属生物有效性的研究进展

淡水重金属污染已成为全球关注的热点环境问题之一。沉积物作为重金属的重要储库与污染内源,可对水环境质量及水生态系统产生严重危害。生物有效性是评价重金属生物可利用性及其毒性效应的关键指标,研究淡水沉积物中重金属的生物有效性与调控机制,有助于阐明重金属的污染机理及其生态环境效应,可为重金属的污染防治提供科技支撑。本文回溯了沉积物重金属生物有效性的定义内涵、发展历史,重点介绍了重金属生物有效性评价的主要方法、适用性及其优缺点,归纳了影响重金属生物有效性的主要因素与内在机制,概述了目前国内外典型河流、湖泊和水库等淡水水体沉积物中相关研究的最新进展。本文进一步指出,在今后研究中亟需整合现有分析方法,形成统一的沉积物重金属生物有效性评价指标与方法体系,并开展权威实验室比对研究。同时,应考虑不同淡水生态系统的区域差异性,采用生物监测方法与原位被动采样技术相结合,将生物配位体模型纳入重金属的生态毒理效应研究中。最终,依据不同淡水环境的特性,尽快建立相应的沉积物重金属质量基准,加强重金属环境污染的科学管理。