混合单体对等离子体法改性PTFE膜微生物亲和性能的影响

膜材料氧传质性能和微生物亲和性对MABR（膜曝气生物膜反应器）的稳定运行及处理效果有重要影响,为探究混合单体对等离子体法改性PTFE（聚四氟乙烯）膜微生物亲和性能的影响,采用两步等离子体法分别在PTFE膜表面接枝聚合DOPA（左旋多巴）/GMA（甲基丙烯酸缩水甘油酯）、Lys（赖氨酸）/GMA、BA（苯胺）/GMA和DEA（乙二胺）/GMA四种混合单体,测定改性前、后PTFE膜的微生物亲和性,并进一步确定最佳混合单体改性PTFE膜的氧传质性能.结果表明:与未改性PTFE膜和仅接枝聚合GMA单体改性复合膜相比,DOPA/GMA、Lys/GMA、BA/GMA和DEA/GMA混合单体改性复合膜表面的微生物亲和性均有提高;Lys/GMA混合单体改性复合膜表面的微生物亲和性最佳,显著高于未改性PTFE膜,膜表面的生物量用ρ（DNA）和ρ（TOC）表示,分别为9.67 ng/μL和103.44 mg/L,比未改性PTFE膜高出34.7%和286.0%,同时其膜表面的生物量增加速度最快;DOPA/GMA和DEA/GMA混合单体改性膜表面的微生物亲和性相近,且高于BA/GMA混合单体改性膜;Lys/GMA混合单体改性复合膜的最大氧传质系数为1.17 m/d（操作压力为35 kPa）,显著高于未改性PTFE膜的0.48 m/d（操作压力为11 kPa）.研究显示,两步等离子体法接枝聚合的混合单体改性能够同时改善PTFE膜的微生物亲和性和氧传质性能,更适合于制备MABR复合膜,可为开发MABR专用膜材料提供理论基础和技术支持.      

光和生物改性溶解性有机质介导17α-乙炔基雌二醇厌氧降解

自然水体溶解性有机质(DOM)在光照和微生物存在的条件下理化性质会发生改变,从而影响其对类固醇类雌激素降解的介导作用.本研究通过对从洱海沉积物中提取的两种典型DOM物质—胡敏酸(HA)和富里酸(FA)分别经过72 h的微生物改性和48 h的光改性,分别比较厌氧条件下光改性前后DOM介导微生物降解17α-乙炔基雌二醇(EE2)的能力变化,以及微生物改性前后DOM介导光降解EE2的能力变化.同时,通过紫外可见吸收光谱、三维荧光光谱和电子供给能力对改性前后的DOM进行分析.结果表明:经过微生物改性后,HA和FA的荧光强度和腐殖化程度都有所提高,但紫外吸光强度和芳香性降低,并且与污染物的结合能力提高,使得光照条件下其介导的EE2更容易发生降解反应.微生物改性后HA介导下的EE2光降解效果要明显好于FA的介导效果.经过光改性后,HA和FA紫外吸光强度和芳香性升高,荧光强度和电子供给能力降低.光改性后HA介导下的EE2微生物降解效果要明显好于FA的介导效果.可见自然水体中微生物改性DOM介导的EE2降解效果相比光改性DOM的介导更加明显.     

Modelling critical levels of ozone for the forested area of austria modifications of the aot40 concept

GOAL, SCOPE AND BACKGROUND: Ozone is the most important air pollutant in Europe for forest ecosystems and the increase in the last decades is significant. The ozone impact on forests can be calculated and mapped based on the provisional European Critical Level (AOT40 = accumulated exposure over a threshold of 40 ppb, 10,000 ppb x h for 6 months of one growing season calculated for 24 h day(-1)). For Norway spruce, the Austrian main tree species, the ozone risk was assessed in a basis approach and because the calculations do not reflect the health status of forests in Austria, the AOT40 concept was developed. METHODS: Three approaches were outlined and maps were generated for Norway spruce forests covering the entire area of Austria. The 1st approach modifies the AOT40 due to the assumption that forests have adapted to the pre-industrial levels of ozone, which increase with altitude (AOTalt). The 2nd approach modifies the AOT40 according to the ozone concentration in the sub-stomata cavity. This approach is based on such factors as light intensity and water vapour saturation deficit, which affect stomatal uptake (AOTsto). The 3rd approach combines both approaches and includes the hemeroby. The pre-industrial ozone level approach was applied for autochthonous ('natural') forest areas, the ozone-uptake approach for non-autochthonous ('altered') forest areas. RESULTS AND DISCUSSION: The provisional Critical Level (AOT40) was established to allow a uniform assessment of the ozone risk for forested areas in Europe. In Austria, where ozone risk is assessed with utmost accuracy due to the dense grid of monitoring plots of the Forest Inventory and because the continuously collected data from more than 100 air quality measuring stations, an exceedance up to the five fold of the Critical Level was found. The result could lead to a yield loss of up to 30-40% and to a severe deterioration in the forest health status. However, the data of the Austrian Forest Inventory and the Austrian Forest Damage Monitoring System do not reflect such an ozone impact. Therefore, various approaches were outlined including the tolerance and avoidance mechanisms of Norway spruce against ozone impact. Taking into consideration the adaptation of forests to the pre-industrial background level of ozone, the AOT40 exceedances are markedly reduced (1st approach). Taking into account the stomatal uptake of ozone, unrealistic high amounts of exceedances up to 10,000 ppb x h were found. The modelled risk does not correspond with the health status and the wood increment of the Austrian forests (2nd approach). Consolidating the forgoing two approaches, a final map including the hemeroby was generated. It became clear that the less natural ('altered') forested regions are highly polluted. This means, that more than half of the spruce forests are endangered by ozone impact and AOT40 values of up to 30,000 ppb x h occur (3rd approach). CONCLUSIONS: The approaches revealed that a plausible result concerning the ozone impact on spruce forests in Austria could only be reached by combining pre-industrial ozone levels, ozone flux into the spruce needles and the hemeroby of forests.     

改性粉煤灰处理含铬废水的研究

在粉煤灰中添加适量的转炉铁泥经盐酸溶解后 ,制得改性粉煤灰 ,在适宜的工艺条件下 ,对六价铬和总铬都有良好的处理效果。经多项实验证明 ,此工艺方法技术可行 ,适用于小型企业间歇排放。     

行为矫正法在建筑火灾安全中的应用研究

随着建筑物防火性能化的发展以及人行为机理的复杂性 ,要求应用更多的学科研究建筑物火灾中人的行为与安全疏散理论。行为矫正学是一门基于过去经验与实验研究的学科 ,笔者在阐述其基本原理和特点的基础上 ,提出了在灾害事故中应用此方法的模式 ,然后结合高层建筑物火灾疏散的特点 ,对高层居民建筑物发生火灾时 ,如何矫正人的一些不正确F行为和提高火灾安全进行了探讨。分析了矫正模式的功能和干预的措施。     

A NEW CHALLENGE FOR WESTERN WATER SUPPLIES1

ABSTRACT: In many of the limited water resource areas of the western United States most water supplies have been put to beneficial uses. Energy, a fast expanding high-priority water use, is making challenging demands for these limited supplies. Can water supplies be stretched, supplemented, or redirected so that present uses can be maintained and energy water needs satisfied? The Bureau of Reclamation is investigating innovative methods of water management, reregulation, and use to meet these demands. Related programs under study include potentials for: development of additional hydroelectric power, installation of low-head turbines in western water courses, utilization of pumped storage and underground storage, use of geo-thermal heat, extension of water supplies through more efficient irrigation systems and practices, and weather modification.     

A Social Contract for Biotechnology: Shared Visions for Risky Technologies?

Future technological developmentsconcerning food, agriculture, and theenvironment face a gulf of social legitimationfrom a skeptical public and media, in the wakeof the crises of BSE, GM food, and foot andmouth disease in the UK (House of Lords, 2000). Keyethical issues were ignored by the bioindustry,regulators, and the Government, leaving alegacy of distrust. The paper examinesagricultural biotechnology in terms of a socialcontract, whose conditions would have to be fulfilled togain acceptance of novel applications. Variouscurrent and future GM applications areevaluated against these conditions. Successwould depend critically on how far a sharedvision can be found with the public. Tore-establish trust, significant changes areidentified in the planning and pursuit ofbiotechnology.     

阳离子改性粘土对活性染料的脱色作用

金属离子改性的凹凸棒石和膨润土对水中活性艳红染料Ｋ－２ＢＰ的吸附脱色作用符合Ｆｒｅｕｎｄｌｉｃｈ吸附等温式并呈现一级反应动力学的特征，吸附的最佳ＰＨ范围分别为〈５和〈６，其中以改性凹凸棒石的吸附性能较好，光照检验表明，改性膨润土还具有一定的光化学催化降解作用。     

废旧塑料的综合利用

综合利用废旧塑料,解决"白色污染",已成为全球的研究热点。从废旧塑料的直接利用、改性利用、热分解、与煤共液化等几个方面综述了废旧塑料的综合利用途径,其中废旧塑料与煤共液化处理技术很有发展前途,将成为今后研究的新热点。     

Graphitic carbon nitride-based photocatalysts in the applications of environmental catalysis

Semiconductor photocatalytic technology has shown great prospects in converting solar energy into chemical energy to mitigate energy crisis and solve environmental pollution problems. The key issue is the development of high-efficiency photocatalysts. Various strategies in the state-of-the-art advancements, such as heterostructure construction, heteroatom doping, metal/single atom loading, and defect engineering, have been presented for the graphitic carbon nitride (g-C₃N₄)-based nanocomposite catalysts to design their surface chemical environments and internal electronic structures to make them more suitable for different photocatalytic applications. In this review, nanoarchitecture design, synthesis methods, photochemical properties, potential photocatalytic applications, and related reaction mechanisms of the modified high-efficiency carbon nitride-based photocatalysts were briefly summarized. The superior photocatalytic performance was identified to be associated with the enhanced visible-light response, fast photoinduced electron-hole separation, efficient charge migration, and increased unsaturated active sites. Moreover, the further advance of the visible-light harvesting and solar-to-energy conversions are proposed.