溶剂热法合成SnWO_4及其可见光催化活性

采用溶剂热法合成了新型的可见光催化剂SnWO4,以甲基橙为目标污染物,考察了合成温度、合成时间和煅烧工艺对催化剂可见光催化活性的影响。实验结果表明:煅烧工艺会明显降低催化剂的光催化活性;在合成温度为180℃、合成时间为8h、未煅烧的条件下,合成的催化剂的光催化效果最好,光照90min后,对甲基橙的降解率可达99.93%。     

Organochlorine pesticides and PCBs in fish from lakes of the Tibetan Plateau and the implications

High mountains may play significant roles in the global transport of persistent organic pollutants (POPs). This work aims to investigate the levels, patterns and distribution of semi-volatile organoclorine pollutants and to improve the understanding of the long-range atmospheric transport and fate of contaminants on the Tibetan Plateau. A total of 60 fish samples were collected from eight lakes located between 2813 and 4718 m above sea level across the Plateau. Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) including dichlorodiphenyltrichloroethane and its metabolites (DDTs), hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) were measured in fish muscle. The results showed that concentrations of DDT, HCH and HCB were comparable to or lower than those found in remote mountains of Europe, Canada and US, while PCB concentrations in fish were, on average, about 4-150 times lower on Tibet than at other mountain areas. The transport and fate of contaminants in the Plateau are significantly influenced by the unique climatological and meteorological conditions, particularly by the summer Indian monsoon and winter westerly jet stream.     

油田作业废水处理技术研究进展

文章讨论了作业废水的组成与特点,并对近年来钻井废水处理工艺,酸化废水处理工艺,压裂废水处理工艺进行了总结与评述。根据作业废水的处理现状,对未来作业废水的处理技术进行了展望。油田废水处理主要向以下三个方面发展:开发新型处理药剂;建立高效处理工艺流程;从污水源头开始控制。     

复合填料热传导过程数值模拟

复合填料由废铸砂、粉煤灰、聚苯乙烯(EPS)颗粒、水泥和水按一定质量比例混合制成,具有低导热性、抗冻胀和轻质特性。根据热阻力法则和比等效导热系数相等法则,将材料视为由大量正方形单元体组成,其中心为一个球形EPS颗粒,这种单元体与总体的导热系数相等。运用AN SY S软件对复合填料单元体的传热过程进行了有限元模拟,根据瞬态法导热系数测试原理,推求不同EPS掺入比情况下的复合填料导热系数,分析EPS颗粒与导热系数的关系,发现材料导热系数随着EPS掺入比的增加而快速降低。将材料导热系数数值模拟与实测结果作比较,发现有限元模拟值与实测值接近,说明采用有限元方法可以实现对材料传热过程的模拟。     

Dietary uptake of polybrominated diphenyl ethers (PBDEs), occurrence and profiles, in aquacultured turbots (Psetta maxima) from Galicia, Spain

Polybromodiphenyl ethers (PBDEs) are one of the many toxic chemicals present in the environment and in the food we eat every day, being fish one of the main sources of persistent organic pollutants in our diet; like other lipid-related contaminants, they are of concern since they can bioaccumulate and biomagnify through the trophic chain. We published a study focused on the dietary uptake of dioxins and furans (PCDD/Fs) and dioxin-like polychlorobiphenyls (dl-PCBs) in a set of samples of Spanish farmed turbot (Blanco et al., 2007). In the present paper, we extend the study to PBDEs to provide more information about the uptake and transfer from feed to fish of halogenated contaminants. PBDEs in the feeds (2.35-4.76 ng g(-1)) were reflected in turbot fillets (0.54-2.05 ng g(-1)): predominant congeners were tetra-BDE 47, penta-BDEs 99 and 100. It is remarkable that tetra-BDE 49, accounting for only 2% in the feed, contributed to 15% of total PBDEs in turbot fillets. Dietary net accumulation values, 30-45%, showed that tri-, tetra-, penta- and hexa-BDEs were as efficiently transferred into turbot as dl-PCBs and tetra- and penta-chlorinated PCDD/Fs. Lipid-normalized biomagnification factors relating concentration in fish and in feed, BMFs>1 were obtained, except for BDE 209. BDE 49 accumulation, 90%, was possibly contributed by metabolism of higher brominated BDEs. Implication in aquaculture management is a need for uncontaminated fish feed to offer safe products.     

TiO2/凹凸棒土复合催化剂的制备及光催化降解活性大红

以凹凸棒土作为载体,以 TiOSO4为钛源,采用超声分散-再沉淀法制备了 TiO2粒径为 10 nm 左右的锐钛矿型 TiO2/凹凸棒土复合催化剂.并采用 X 射线衍射仪、透射电子显微镜、X 射线能谱仪对复合催化剂进行了表征.制备复合催化剂的最佳条件:凹凸棒土与 TiO2的质量比为 1:3.0,煅烧温度为 450 ℃....     

Solid waste management practices in Turkey

As an economically developing country, Turkey has very well operated integrated solid waste management applications structured on modern facilities, besides over 2,000 scattered open dump areas in the country. Integrated waste management applications seem eligible for the metropolitan cities like Istanbul and Izmit (Kocaeli). Attempts have not been encouraging for the scattered regional settlements using central storage sites due to financial shortages and received rejections from nearby settlements. Small-scale compact solid waste management systems with materials recycling and composting can be more suitable alternatives in the small-scale regional settlements. The major constituents of municipal solid waste are organic in nature and approximately a quarter of municipal solid waste is recyclable. Although paper, including cardboard, is the main constituent, the composition of recyclable waste varies strongly by the source or the type of collection point. Solid wastes need primary treatment in order to be suitable for incineration and composting. Turkey needs to give more emphasis on the usage of modern solid waste removal technologies to overcome the overgrowing solid waste disposal problems.     

IC反应器处理MTO废水的中试研究

中试研究了内循环(IC)反应器处理甲醇制烯烃(MTO)废水的启动和运行过程,同时考察了颗粒污泥的性状及沼气产量的变化情况。试验过程运行稳定,系统抗冲击性强。以絮状污泥为接种污泥,经过131 d的启动和运行,IC反应器的COD去除负荷可达10 kg/(m~3·d)以上,COD去除率可达90%以上。IC反应器中的成熟颗粒污泥形状规则、密实、粒径大、沉降速率快。IC反应器的沼气产量符合理论预期。     

脉冲电晕反应器结构对乙硫醇消除效果的影响

研究了脉冲电晕等离子体反应器结构的变化对乙硫醇消除效果的影响规律。结果表明,在反应器内设置折流板,可以增加气流的湍动程度,有利于活性粒子与污染物的充分接触,从而提高消除率。高压电极间距对电晕区范围及消毒效果有较大影响,间距较小将导致各电极产生的电场相互干扰明显,消除率减小;而电极间距过大,虽然电极间电场分布相互干扰小,但是反应器内可排布的电极数减少,总电晕区减少,消除率也减小。根据实验结果,电极间距设置为50 mm比较合理。另外,在相同的电场强度和脉冲频率下,毛刺形高压电极比线电极结构能耗低,能量利用率高。     

含中间层的DSA电极电催化氧化硝基苯废水的研究

为了提高难降解有机废水的可生化性,以及更高效地去除废水中的特征污染物,同时避免二次污染,利用自制的含锡锑中间层的钌钯氧化物涂层电极对有机废水中的硝基苯进行处理,并利用SEM、XRD等方法对电极中间层、表层进行微观表征。微观测试表明,基体、中间层、表层之间结合力较强,有利于增强电极寿命;水处理实验表明,电催化氧化反应体系适合高浓度有机废水的处理,由于该反应体系需要外加电解质加强传质,这在实际运用中为废水中盐度的处理提供了一种新的途径,当电流密度为20 mA/cm²、电解质浓度为10 g/L、pH=5、极板间距=2 cm时,电催化氧化体系对硝基苯具有较高的去除效率。