长期暴露于全氟十三酸的青鳉鱼体内分布和生物富集

研究了将青鳉鱼长期暴露于不同浓度的全氟羧酸类物质全氟十三酸(PFTriDA)后的器官分布和富集系数.结果显示, PFTriDA最高富集在性腺;其次是卵、肝脏;浓度最低的部分是残体.除了性腺之外,该器官分布与野生中华鲟的一致.在相同暴露浓度下,雄鱼体内各器官的PFTriDA的含量高于雌鱼,机理模型计算进一步表明高母子传递系数是造成雌雄差异的可能原因.随着PFTriDA暴露浓度的升高,鱼体内同一器官的生物富集系数(BCF)呈现下降趋势.     

青岛大气气溶胶中氨基化合物的分布特征

氨基化合物是大气气溶胶和雨水中常被检出的一类有机氮化合物,由于其可作为生物生长直接的氮源,因此可能对海洋生态系统产生直接作用.利用2008年1～12月在青岛采集的66个总悬浮颗粒物样品,采用邻苯二甲醛/N-乙酰-L-半胱氨酸柱前衍生高效液相色谱法,分析了其中溶解态(DAC)和颗粒态氨基化合物(PAC)的浓度.气溶胶中DAC浓度为2.4～40.9nmol·m-3,在春季最高,夏季次之,秋季、冬季最低.PAC浓度为0.7～76.1nmol·m-3,呈现春季冬季秋季夏季的变化趋势.不同季节氨基化合物的组成不同.依据气团的后向轨迹,气溶胶样品可分为受北方陆源、南方陆源和海洋源影响,DAC和PAC在受南方陆源影响的气溶胶中浓度最高,北方陆源次之,海洋源气溶胶中最低.不同来源的气溶胶中氨基化合物的组成不同,蛋白质类氨基化合物对总氨基化合物的贡献在海洋源气溶胶中最高,在南方源气溶胶中最低.     

Effect of platinum on the photocatalytic degradation of chlorinated organic compound

TiO2 nanoparticles, doped with di erent Pt contents, were prepared by a modified photodeposition method using Degussa P-25 TiO2, H2PtCl6 6H2O and methanol as the solvents. The physicochemical properties of Pt/TiO2 were investigated by the nitrogen adsorption and desorption isotherm measurement technique, X-ray di raction analysis and photoluminescence spectra, respectively. Reaction rates from photocatalytic removal of dichloromethane over Degussa P-25 TiO2 and Pt/TiO2 were evaluated. The average diameter and BET surface area of the TiO2 catalyst particles were 300 nm and 50 m2/g, respectively. The degradation e ciency was 99.0%, 82.7%, 55.2%, and 57.9% with TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. And the degradation e ciency was 99.3%, 79.7%, 76.5%, and 73.4% with a 0.005 wt.% Pt/TiO2 at inlet concentrations of 50, 100, 200, and 300 ppm, respectively. In addition, we found that the photoluminescence emission peak intensities decreased with increases in the doping amount of Pt, which indicates that the irradiative recombination was weakened. Furthermore, the results showed that the UV/0.005 wt.% Pt/TiO2 process was capable of e ciently decomposing gaseous DCM in air.     

Modeling the influence of ethanol on the adsorption and desorption of selected BTEX compounds on bentonite and kaolin

The study investigated the effects of ethanol on the adsorption properties of bentonite and kaolin for benzene and toluene removal.     

Beyond hypoxia：Occurrence and characteristics of black blooms due to the decomposition of the submerged plant Potamogeton crispus in a shallow lake

Organic matter-induced black blooms(hypoxia and an offensive odor) are a serious ecosystem disasters that have occurred in some large eutrophic shallow lakes in China. In this study, we investigated two separate black blooms that were induced by Potamogeton crispus in Lake Taihu, China. The main physical and chemical characteristics, including color- and odor-related substances, of the black blooms were analyzed. The black blooms were characterized by low dissolved oxygen concentration(close to 0 mg/L), low oxidation-reduction potential, and relatively low pH of overlying water. Notably higher Fe2+and∑S2-were found in the black-bloom waters than in waters not affected by black blooms. The black color of the water may be attributable to the high concentration of these elements, as black FeS was considered to be the main substance causing the black color of blooms in freshwater lakes. Volatile organic sulfur compounds, including dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, were very abundant in the black-bloom waters. The massive anoxic degradation of dead Potamogeton crispus plants released dimethyl sulfide, dimethyl disulfide, and dimethyl trisulfide, which were the main odor-causing compounds in the black blooms. The black blooms also induced an increase in ammonium nitrogen and soluble reactive phosphorus levels in the overlying waters. This extreme phenomenon not only heavily influenced the original lake ecosystem but also greatly changed the cycling of Fe, S, and nutrients in the water column.     

Unregulated emissions from diesel engine with particulate filter using Fe-based fuel borne catalyst

The alteration and formation of toxic compounds and potential changes in the toxicity of emissions when using after-treatment technologies have gained wide attention. Volatile organic compound（VOC）, carbonyl compound and particle-phase polycyclic aromatic hydrocarbon（PAH） emissions were tested at European Steady State Cycle（ESC） to study unregulated emissions from a diesel engine with a fuel-borne catalyst and diesel particulate filter（FBC–DPF）. An Fe-based fuel-borne catalyst was used for this study. According to the results, brake specific emissions of total VOCs without and with DPF were 4.7 and4.9 mg/kWh, respectively, showing a 4.3% increase. Benzene and n-undecane emissions increased and toluene emission decreased, while other individual VOC emissions basically had no change. When retrofitted with the FBC–DPF, total carbonyl compound emission decreased 15.7%, from 25.8 to 21.8 mg/kWh. The two highest carbonyls, formaldehyde and acetaldehyde, were reduced from 20.0 and 3.7 to 16.5 and 3.3 mg/kWh respectively. The specific reactivity（SR） with DPF was reduced from 6.68 to 6.64 mg/kWh. Total particle-phase PAH emissions decreased 66.4% with DPF compared to that without DPF. However, the Benzo[a]pyrene equivalent（BaPeq） with DPF had increased from 0.016 to 0.030 mg/kWh.Fluoranthene and Pyrene had the greatest decrease, 91.1% and 88.4% respectively. The increase of two- and three-ring PAHs with DPF indicates that the fuel-borne catalyst caused some gas-phase PAHs to adsorb on particles. The results of this study expand the knowledge of the effects of using a particulate filter and a Fe-based fuel-borne catalyst on diesel engine unregulated emissions.     

Carbonyl emissions from heavy-duty diesel vehicle exhaust in China and the contribution to ozone formation potential

Fifteen heavy-duty diesel vehicles were tested on chassis dynamometer by using typical heavy duty driving cycle and fuel economy cycle. The air from the exhaust was sampled by 2,4- dinitrophenyhydrazine cartridge and 23 carbonyl compounds were analyzed by high performance liquid chromatography. The average emission factor of carbonyls was 97.2 mg/km, higher than that of light-duty diesel vehicles and gasoline-powered vehicles. Formaldehyde, acetaldehyde, acetone and propionaidehyde were the species with the highest emission factors. Main influencing factors for carbonyl emissions were vehicle type, average speed and regulated emission standard, and the impact of vehicle loading was not evident in this study. National emission of carbonyls from diesel vehicles exhaust was calculated for China, 2011, based on both vehicle miles traveled and fuel consumption. Carbonyl emission of diesel vehicle was estimated to be 45.8 Gg, and was comparable to gasolinepowered vehicles （58.4 Gg）. The emissions of formaldehyde, acetaldehyde and acetone were 12.6, 6.9, 3.8 Gg, respectively. The ozone formation potential of carbonyls from diesel vehicles exhaust was 537 mg O3/km, higher than 497 mg O3/km of none-methane hydrocarbons emitted from diesel vehicles.     

神奇的“水燃料”

你想象过以后开车,只需要加水就能跑吗？水是地球上最为丰富的化合物,一直以来,人类从未停止过探索水燃料的脚步。今天要介绍的,就是那些从水中提取能源的神奇科技。     

广东省新型POPs监测防控体系建设研究

2009年和2011年斯德哥尔摩公约新纳入的9种和1种持久性有机污染物（POPs）的研究是目前国际上环境领域研究的热点之一,所引起的环境污染和人体健康问题也逐步得到中国环保部门的关注.随着国际斯德哥尔摩公约履约活动的不断深入,中国正面临着履行公约以及削减与控制持久性有机污染物的巨大挑战.本文总结了广东省新型持久性有机污染物监测防控体系建设的必要性和意义,阐述了国内外在该领域的研究现状以及对解决新型POPs问题的作用.     

CO2捕集回收技术研究

主要介绍了常用的胺化合物吸收法、钙基吸收剂法、金属氧化物法等CO2捕集回收技术的最新研究进展及存在的问题,综合对比了各种方法的优缺点:胺化合物吸收法吸收速率快,但再生能耗较高,因此开发"高效低耗"的复合吸收剂成为研究的重点;钙基吸收剂法在高温环境下对CO2的吸收有较好的效果,但吸收剂的碳酸化转化率及热稳定性是有待解决的关键问题;金属氧化物法具有高的CO2吸收效率,但成本较高.在此基础上,探索了CO2捕集回收技术改进工艺,提出改善吸收剂性能、开发高效低耗的CO2选择性吸收剂将成为今后CO2捕集回收技术的研究方向.