动态混合曝气-微电解预处理维生素B1生产废水

维生素 B1 生产废水具有有机污染物浓度高、色度大、水量冲击大和可生化性差等特点.为了减轻后续和生化处理的压力,提出了动态混合曝气-微电解工艺进行预处理,通过单因素对比试验考察了各因素对出水效果的影响,得出最佳控制参数为:进水 pH 值为 5,曝气时间为 2 h,铁碳体积比为 0.5,气水比为 200,充水比为0.5,混凝体积比为5.TOC(原水52 120 mg/L)和色度(原水为 1 000 倍)去除率分别达到 34.9%和44%,为后续生化处理奠定了坚实的基础.     

低频超声协同Fe-Ni-Mn/Al_2O_3催化降解酸性绿B的研究

采用低频超声与Fe-Ni-Mn/Al2O3催化剂协同降解偶氮染料酸性绿B模拟废水,考察染料初始浓度和pH值、催化剂、饱和气体及H2O2等因素对酸性绿B降解效果的影响,结果表明:催化剂Fe-Ni-Mn/Al2O3与低频超声存在协同效应,催化剂的最佳投加量为6 g/L;酸性条件有利于染料的超声降解,当pH=3.8时,可取得最佳的降解效果;酸性绿B降解率随初始浓度的增大而降低,其优化初始浓度为100 mg/L,此外,在反应体系中鼓入饱和气体也可促进酸性B的降解,且影响顺序为混合气体(air+Ar)>氧气>氩气;在反应过程中投加H2O2有利于染料降解率的提高.在优化实验条件下降解150 min,酸性绿B色度去除率达到91.4%.     

催化铁内电解反应床对水中酸性红B的脱色研究

在铁内电解法的基础上发展出的铁镀铜滤料构成的催化铁内电解反应床，并以酸性红B为目标染料，研究了催化铁内电解反应床的脱色性能。结果表明，在不同初始pH条件下，催化铁内电解反应床对水中酸性红B的脱色效果均优于单一铁内电解反应床。在水力停留时间为2 h，进水pH值为7.2，汽水比为1∶30的条件下，催化铁内电解反应床对100 mg/L酸性红B的平均脱色率为88.5％，高于单一铁内电解反应床约9％。另外，适当增加曝气可以增加铁内电解反应床的脱色效果。     

Evaluation of alternative approaches for screening contaminated sediments and soils for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans

Traditional high resolution mass spectrometry (HRMS) analysis for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) can be time consuming and expensive. Consequently, alternative methods are of great interest to regulatory agencies and others characterizing contaminated sites. One factor that hinders acceptance of alternative methods is a lack of performance information that assesses the alternative method's impacts on analytical results. The U.S. Environmental Protection Agency's Superfund Innovative Technology Evaluation Monitoring and Measurement Technologies Program (EPA SITE MMT) encourages the development and implementation of innovative and alternative monitoring methods by providing performance information on site characterization technologies. This paper presents a comparison of the results obtained from laboratory-based alternative approaches for screening sediment and soil samples for dioxin toxicity equivalents (TEQ(D/F)) to results obtained using traditional HRMS. The laboratory-based approaches included modifying the traditional HRMS analysis to make it more cost-effective (alternate 1613B), analyzing extracts that had been prepared for HRMS using low resolution mass spectrometry, and determining total organic carbon (TOC) content as an indicator of PCDD/F content. These comparisons demonstrated that TEQ(D/F) values generated using toxicity equivalency factors proposed by the World Health Organization in 1998 applied to alternate 1613B and LRMS analyses have a strong linear correlation to the TEQ(D/F) values derived in the same fashion from traditional HRMS analysis. These results would have placed >90% of the samples within the same concentration intervals using ranges of <0.05, 0.05-0.50, 0.50-5, and >5ng TEQ/g. Natural log transformed data for TOC had significantly weaker correlation to TEQ(D/F), indicating that TOC is not a reliable indicator of TEQ(D/F) concentrations.     

纳米TiO2混合晶体的制备及其光催化降解活性

以乙酸为水解抑制剂，采用sol-gel法制备纳米TiO2混合晶体催化剂，考察了抑制剂用量、煅烧温度、粒径等对催化性能的影响．结果表明，乙酸的用量影响催化剂的活性，当CH3COOH：Ti(OBu)4=0．8—1．0：1时效果较好；煅烧温度直接影响混合晶体的组成，580℃时锐钛矿／金红石=20．62，650℃时锐钛型／金红石=2．46，混合晶体具有较高的催化性能，粒径大小对TiO2的催化性能影响很大，粒子尺寸愈小，则比表面积愈大，电子．空穴愈难复合，有利于对活性艳红X-3B的降解．     

Benzo[a]pyrene exposure influences the cardiac development and the expression of cardiovascular relative genes in zebrafish (Danio rerio) embryos

It is reported that the most abundant polycyclic aromatic hydrocarbons (PAHs) in weathered crude oils are cardiotoxic. However, the action mechanism of PAHs on vertebrate cardiovascular development and disease is unclear. In the present study, the cardiac morphology and functioning of zebrafish embryos exposed to benzo[a]pyrene [B(a)P], as a high-ring PAHs, for 72 h were observed and determined. The results showed that B(a)P exposure resulted in cardiac developmental defects in zebrafish embryos. Significant changes in expression level of multiple genes potentially critical for regulating the B(a)P-induced cardiovascular developmental defects were also found. A gene network regulating cardiac development perturbed by B(a)P exposure was identified and established by computational analysis and employment of some databases. The information from the network could provide a clue for further mechanistic studies explaining molecular events regulating B(a)P-mediated cardiovascular defects and consequences.     

Projecting Spatial Patterns of Flood Hazard: Recent Climate and Future Changes over Yangtze River Basin

Projection of hazard changes in climate extremes is critical to assessing the potential impacts of climate change on human and natural systems. Using simulations of providing regional climates for impacts studies, five indicators (rainstorm days, maximum 3-day precipitation, elevation, gradient and distance from river or lake) were selected to project the spatial patterns of flood hazard over Yangtze River Basin for the baseline period (1961– 1990) and future (2011–2100) under SRES B2 scenario. The results ...     

影响YYG-4B型冷原子荧光测汞仪诸因素分析

对YYG－4B型冷原子荥光测汞仪在测试中常出现的各种因素进行了分析探讨，提出了可行的解决方法，进一步提高了测定结果的精密度和准确度。     

溴酸钾氧化氨基黑10B催化光度法测定痕量亚硝酸根

研究了在磷酸介质中 ,痕量亚硝酸根对溴酸钾氧化氨基黑 1 0 B的催化褪色作用 ,建立了催化动力学光度法测定痕量亚硝酸根的新方法 ,并探讨了动力学反应条件 ,方法的线性范围为 0～ 1μg/1 0 ml,检出限为 4.88× 1 0 - 9g/ml,用于地面水及雨水中亚硝酸根的测定 ,结果满意。