不同共代谢基质下厌氧生物降解间苯二酚的研究

分别用蔗糖、葡萄糖、丁酸盐和乙醇作为驯化好的厌氧污泥的共代谢基质,在厌氧序批式反应器(ASBR)中对间苯二酚的降解进行研究。结果表明:共代谢基质SCOD浓度在500～2000mg/L时,间苯二酚的降解速率很高;试验回归结果表明反应均符合一级动力学方程;反应速率常数大小依次为k丁酸盐>k蔗糖>k葡萄糖>k乙醇;当两种共代谢基质按比例1:1(SCOD)混合投加后,反应速率常数大小依次为k葡萄糖+丁酸盐>k乙醇+丁酸盐>k葡萄糖+乙醇,其中葡萄糖和丁酸盐的混合基质降解速率最高。     

脲酶抑制法检测环境样品中重金属离子研究

为探索利用脲酶快速检测环境样品中重金属离子的最佳条件，系统研究了重金属和缓冲液类型及其浓度对脲酶抑制率的影响。结果表明，不同浓度缓冲液中重金属离子浓度与脲酶抑制率呈显著的相关性，表现为随着重金属离子浓度的增加，脲酶抑制率也提高。缓冲液类型和浓度均能影响重金属对脲酶的抑制作用，其中磷酸缓冲液中，无论是Hg^2 还是Cu^2 对脲酶活性均有较强的抑制作用：在柠檬酸缓冲液中2种离子对脲酶的抑制作用存在显著差异。建立脲酶抑制检测技术的关键是选择合适的缓冲系统。此结果为脲酶抑制法在快速检测重金属离子中最佳检测条件的选择提供了理论依据。     

三价砷和五价砷对活性污泥几种酶活性的影响

应用静态试验,研究了As(Ⅲ),As(Ⅴ)对活性污泥脱氢酶活性、脲酶活性、蛋白酶活性的影响。其结果:抑制10%脱氢酶、脲酶、蛋白酶活性的As(Ⅲ)浓度分别为10.0mg/gMLSS,13.4mg/gMLSS,2.6mg/gMLSS;As(Ⅴ)的浓度则分别为552.6mg/gMLSS,464.4mg/gMLSS,193.7mg/gMLSS。As(Ⅲ)对活性污泥的毒性比As(Ⅴ)平均大53倍。     

UV-B辐射增强对褶皱臂尾轮虫摄食的影响

运用生态毒理学方法,研究了UV-B辐射条件下褶皱臂尾轮虫(Brachinonus plicatilis)对6株海洋微藻:小球藻(Chlorella sp.、绿色巴夫藻(Pauloua uiridis)、扁藻(Tetraselmis chuii)、球等鞭金藻8701(Isochrysis galbana Park 8701)、牟氏角毛藻(Chaetoceros muelleri Lermumerman)和小新月菱形藻(Nitzschia clostertum)的摄食.结果表明:UV-B辐射增强对褶皱臂尾轮虫的摄食有显著的抑制作用.与对照组相比,褶皱臂尾轮虫对每一种饵料单胞藻的滤水率和摄食率都表现出,随UV-B辐射剂量的增大而显著减小(P＜0.5).而且对每一种饵料单胞藻的滤水率和摄食率是不相同的,这说明褶皱臂尾轮虫对饵料单胞藻是有选择性的.     

废水中GaAs、Ga3+、Ge4+对活性污泥脱氢酶的影响及其抑制动力学

以活性污泥脱氢酶的活性作为毒性指标,研究了半导体材料GaAs、Ga³⁺、Ge⁴⁺对活性污泥活性的抑制影响,并用Hg²⁺作为参比材料;同时对抑制动力学也作了初步研究。实验表明,GaAs、Ga³⁺、Ge⁴⁺及Hg²⁺的10％抑制浓度分别为45.00,371.63,0.13ppm/gMLSS,GaAs、Ga³⁺、Ge⁴⁺和Hg²     

人工湿地基质除磷影响因素研究进展

基质除磷被认为是人工湿地中磷去除的主要方式。人工湿地基质除磷不仅受其自身化学特性的影响,还受到废水磷负荷、水力条件、运行方式、温度、溶解氧、pH、竞争性离子等的影响,结合国内外的最新研究进展较全面地论述了上述因素对基质除磷效果的影响。最后对吸附饱和基质的去向进行了一定的探讨。     

以造粒粉煤灰为过滤介质去除景观水中磷的研究

研究了造粒粉煤灰的最大磷吸附量、磷吸附速率等吸附特征，以及颗粒粒径、磷浓度、水力负荷对景观水除磷效果的影响。还进行了为期21天的连续过滤试验，发现滤床在高水力负荷条件下能持续地去除景观水中的磷。     

Experimental study on the synergistic inhibition effect of nitrogen and ultrafine water mist on gas explosion in a vented duct

In this study, in order to research the synergistic inhibition effect of nitrogen and ultrafine water mist on gas explosion in a vented duct, a semi-confined transparent chamber was designed with the size of 120 × 120 × 840 mm, and the experiments were carried out with stoichiometric methane/air premixed mixture (fraction of methane: 9.5%), adding different fractions of nitrogen and ultrafine water mist. The experimental results showed the following: The combination of nitrogen and ultrafine water mist had a synergistic inhibiting effect on methane/air explosion, which was preferable to the single use of any kind. With the increase of spraying time of water mist and fraction of nitrogen, the initial shape of the explosion flame became snakelike, and at the same time the peak flame propagation speed and peak overpressure decreased significantly. When the nitrogen fraction was increased to 10% and the mist spraying time was increased to 2min, synergistic inhibiting effect on overpressure was high efficient. However, with the increase of spraying time of water mist and fraction of nitrogen going on, the amount of increase of explosion inhibition efficiency was gradually reduced.     

Experimental study on explosion inhibition by heptafluoropropane and its synergy with inert gas

The inhibition effect of heptafluoropropane (CF₃CHFCF₃) on methane explosions under different inhibitor concentrations in a closed vessel was studied. A high-speed camera and a pressure sensor were adopted respectively to record flame propagation characteristics and pressure data. Results indicate that the relationship between flame propagation and pressure rising was correlated. As the equivalent ratio (ϕ)≤1, the pressure presented a trend of rising firstly and then decreasing with increasing CF₃CHFCF₃ concentration, and it was found that there existed a critical concentration for pressure decrease. As ϕ > 1, the pressure exhibited a decreasing trend. Although the pressure appeared to seemingly increase, the moment that the pressure began to rise (t_rise) and the moment that the maximum explosion overpressure appeared (t_Pmax) were obviously delayed. The average rate of pressure rise ((dP/dt)_ave) was decreased as the concentration of CF3CHFCF3 increased. It indicates that CF₃CHFCF₃ can effectively reduce the explosion reaction rate. The critical concentration of CF₃CHFCF₃ for complete inhibition was determined. Meanwhile, the synergy of CF₃CHFCF₃-inert gas can improve the inhibition effect. Compared with CF₃CHFCF₃–N₂, the synergy of CF₃CHFCF₃–CO₂ presented a better inhibition effect, and the inhibition effect was increased with increasing inert gas concentration. And the mechanisms of physical and chemical effects on explosion inhibition were analyzed.     

人工湿地基质对NH4＋-N吸附性能

为研究建筑废物红砖和工业废物煤渣用作人工湿地脱氮基质的可行性，分别通过静态吸附实验和动态NHf—N去除效果实验进行考察。结果表明，红砖和煤渣对NH4＋-N最大静态吸附量分别为0．2533mg／g和0．0533mg／g，其吸附等温曲线均符合Freundlich型吸附方程，吸附常数分别为0．0419和0．0091；红砖煤渣组合对污水中NH4＋-N平均动态脱除率达到41．18％，高于红砖的37．63％和煤渣的30．92％。