氧化物催化剂对非热等离子体催化降解甲苯的影响

考察了在干燥气氛下不同氧化物催化剂对非热等离子体催化降解甲苯的影响。从甲苯降解率、碳平衡、CO2选择性和O3去除4个方面,对比了氧化物催化剂的介电性能、表面供氧能力和比表面积与多孔结构对反应产生影响的强弱。结果表明,催化剂的介电性能有利于甲苯降解率、碳平衡和O3产量的提高,但对CO2选择性和O3去除的影响极小;一定能量密度下,催化剂比表面积与多孔结构对CO2选择性和O3去除所产生的影响要强于介电性能;催化剂表面供氧能力可明显促进反应的进行,其对反应所产生的影响要强于比表面积与多孔结构。     

Hydroxytyrosol, the phenolic compound of olive oil protects human PBMC against oxidative stress and DNA damage mediated by 2,3,7,8-TCDD

The protective effect of hydroxytyrosol (HT), a strong antioxidant compound from extra virgin olive oil, against TCDD induced toxicity was investigated in human peripheral blood mononuclear cells (PBMC). PBMC (1 × 10⁶ cells mL⁻¹) were divided into four groups and were incubated in a CO₂ incubator (5% CO₂) for 12 h with vehicle, TCDD (10 nM), TCDD + HT (10 nM + 100 μM) and HT alone (100 μM) respectively. To clarify the role of HT against TCDD induced cytotoxicity, oxidative stress and the levels of antioxidant enzymes were assessed. Incubation of PBMC with TCDD significantly decreased cell viability, catalase (CAT) and glutathione peroxidase (GPx) and increased the levels of superoxide dismutase (SOD), glutathione reductase (GR) and oxidative stress markers such as lipid peroxidation products (LPO), protein carbonyl content (PCC) and reactive oxygen species (ROS). Whereas, HT had an effective antioxidant property as observed by the increased cell viability, normalization of antioxidant enzymes and decreased levels of LPO, PCC and ROS in PBMC co-treated with HT and TCDD. Apoptosis detection and comet assay results shows that HT, by acting as an antioxidant, prevents the damage to DNA induced by TCDD. In addition light microscopic and histopathological observations revealed that the cells are apoptotic and degenerated during TCDD treatment, whereas cells showed intact morphology during co-treatment with HT. On the whole, the results reveal that HT exerts a promising antioxidant potential in protecting the PBMC against TCDD induced oxidative stress, which might be due to the presence of catechol moiety in its structure.     

大坝下游定点区域溶解氧饱和度预测

大坝通过坝身泄流时,巨大的洪水卷吸空气中的大量气体直泻到下游河床,造成下游河道特别是近坝区域气体含量过饱和,给下游水生生物带来不利影响,其中鱼类气泡病就是水体气体过饱和造成的典型病症。为探明大坝泄流对坝下河道溶解氧饱和度的影响,以三峡 葛洲坝区域坝下近坝区定点区域的溶解氧实测资料为基础,建立溶解氧饱和度的BP网络预测模型,对大坝不同运行工况进行下游溶解氧饱和度的预测仿真计算,并将仿真预测值与实测及数值模拟结果进行比较分析。结果得出BP网络模型能很好地逼近坝下近坝区指定区域的溶解氧饱和度,可根据大坝运行工况对下游水体溶解氧饱和度进行快速预测,为有效控制坝下水体溶解氧饱和度提供借鉴     

Integrated biological responses of zebrafish (Danio rerio) to analyze water quality in regions under anthropogenic influence

This study analyzed water quality in regions around Patos lagoon (Southern Brazil) that are under anthropogenic pressure. Water samples were collected from five different sites, including one used as a source for human consumption (COR) and others known to be influenced by human activities (IP). Danio rerio (Teleostei, Cyprinidae) organisms were exposed for 24 h to these water samples, plus a control group. It was observed that: (1) reactive oxygen species levels were lower in COR and IP than in the control group; (2) glutamate-cysteine ligase (catalytic subunit) expression was higher in COR than in other sites; (3) exposure to all water samples affected long-term memory (LTM) when compared to control group. Thus, some water samples possess the ability to modulate the antioxidant system and to induce a decline in cognitive functions, as measured by LTM. The obtained results indicate that a combination of variables of different organization level (molecular, biochemical and behavioral) can be employed to analyze water quality in impacted regions.     

A2O工艺好氧末段溶解氧变化对脱氮除磷影响

采用连续流A2O工艺处理实际的生活污水,研究好氧末段在不同溶解氧(DO)浓度条件下对污泥沉降性能、系统脱氮除磷的影响,同时考察了DO对污泥硝化活性、厌氧释磷速率和反硝化脱氮速率的影响.结果表明,随着末段溶解氧的提高,污泥容积指数SVI从140降至100左右,后又升高到120～170;系统的硝化效果提高,氨氮的去除率从6...     

pH、溶解氧、叶绿素a之间相关性研究Ⅱ：非养殖水体

利用国内、外近20年的资料和饮用水水源地潘家口水库现场围隔实验结果,分析非养殖水体中pH、溶解氧（DO）和叶绿素a之间的相互关系。结果表明,当水体处于富营养化状态即叶绿素a平均含量高于10μg/L时,pH、DO与叶绿素a呈显著正相关。当叶绿素a平均含量低于10μg/L时,水体交换强或有机重污染的天然水体中DO与叶绿素a...     

阴极氧还原产电生物可渗透反应栅的研究Ⅰ. 不锈钢毛电极模拟反应器

提出利用阴极氧还原和阳极微生物产电作用的产电生物可渗透反应栅（CORE-PRB）方法用于被有机物污染的地下水的修复,并以不锈钢毛为电极建立模拟反应装置验证了CORE-PRB的技术概念。实验中考察了分别以蔗糖＋醋酸盐和不同浓度的污泥消化液为进水时的反应电流,并研究电极距离对反应电流的影响。由于氧还原阴极阳极反应能力的限制,随着与阴极室距离加大,模拟反应装置各阳极室的电流迅速减小。有机基质的可生化性对模拟反应器的总电流也有显著影响。     

Responses of a soil bacterium, Pseudomonas chlororaphis O6 to commercial metal oxide nanoparticles compared with responses to metal ions

The toxicity of commercially-available CuO and ZnO nanoparticles (NPs) to pathogenic bacteria was compared for a beneficial rhizosphere isolate, Pseudomonas chlororaphis O6. The NPs aggregated, released ions to different extents under the conditions used for bacterial exposure, and associated with bacterial cell surface. Bacterial surface charge was neutralized by NPs, dependent on pH. The CuO NPs were more toxic than the ZnO NPs. The negative surface charge on colloids of extracellular polymeric substances (EPS) was reduced by Cu ions but not by CuO NPs; the EPS protected cells from CuO NPs-toxicity. CuO NPs-toxicity was eliminated by a Cu ion chelator, suggesting that ion release was involved. Neither NPs released alkaline phosphatase from the cells’ periplasm, indicating minimal outer membrane damage. Accumulation of intracellular reactive oxygen species was correlated with CuO NPs lethality. Environmental deposition of NPs could create niches for ion release, with impacts on susceptible soil microbes.     

中国ESDPM模型及其在交通需求预测中的应用

交通运输是国民经济的基础部门.未来随着国民经济的快速发展和人均收入水平的不断提高,交通运输部门的能源消费量将会以较高的速度增长,在决定我国终端能耗的局面中占据着非常重要的地位.本文应用集合模型方法建立了中国能源服务需求预测模型( Energy service demand projection model,ESDPM),在对未来经济和社会发展进行合理假设的基础上,预测了中国未来一直到2050年的客运和货运周转量以及小汽车保有量,并进行了国家和地区间的比较.结果显示,2005-2050年中国的客运和货运周转量将分别以年均增长率5.9%和5.1%的速度增长,2050年客运和货运周转量将分别达到23.1万亿人·km和74.7万亿t·km.小汽车将随着人均GDP的快速增加呈现出明显的"S"型增长关系,在小汽车拥有率饱和水平选取为0.4时,小汽车保有量将稳定在5.8亿辆左右.     

中国工业化进程与能源矿产供需均衡的研究

工业化与能源需求的均衡关系及解决工业化进程中能源供需失衡的战略途径是中国工业化进程中需要探讨的重大问题.文章运用协整技术,就1990-2008年间中国工业化进程与能源需求协整关系的检验,认为中国工业化与能源需求增长具有长期稳定的均衡关系,能源需求将继续保持增长,能源利用效率也将持续提高.然而工业化进程中重工业化高能耗结构特征与能源低效利用并存的困境以及能源供需矛盾不利于能源供需平衡的平稳发展.我国应适应工业化进程的基本规律,转变能源消费方式;走新型工业化道路,适当限制低附加值产业发展,鼓励产业向离附加值、低能耗、高技术产业转移;在实现能源开发利用技术进步和创新的同时.有效利用国内外能源资源;建立能源应急机制等战略途径来实现工业化进程中能源供需平衡发展.