Distribution and transportability of hexabromocyclododecane (HBCD) in the Asia-Pacific region using skipjack tuna as a bioindicator

The geographical distribution of hexabromocyclododecane (HBCD) was investigated through analysis of muscle tissue of skipjack tuna (Katsuwonus pelamis) collected from offshore waters of Asia-Pacific region (Japan, Taiwan, Philippines, Indonesia, Seychelles, Brazil, Japan Sea, East China Sea, South China Sea, Indian Ocean and North Pacific Ocean). HBCD was detected in almost all samples analyzed (<0.1 to 45 ng/g lipid weight basis), indicating widespread presence of this compound in the marine environment. Elevated concentrations of HBCD were found in skipjack tuna from areas around Japan, which have the larger modern industrial/urban societies, and implicated these areas as primary regional sources. All three individual HBCD isomers (alpha-, gamma- and beta-HBCD) were detected in almost all samples; the percentage contribution of the alpha-isomer to total HBCD increased with increasing latitude. The estimated empirical 1/2 distance for alpha-HBCD was 8500 km, which is one of the highest atmospheric transportability among various halogenated persistent organic pollutants (POPs).     

A survey of radon level in underground buildings in China

From 2003-2004, using solid state nuclear detectors, a survey of the air radon level in 234 underground buildings in 23 cities of China was carried out during spring as well as summer and winter. The annual radon concentrations in these underground buildings range from 14.9 to 2482 Bq m(-3), with an overall mean value of 247 Bqm(-3). When radon concentrations are averaged according to cities, Fuzhou and Baotou have the relatively higher radon levels, which are 714 and 705 Bqm(-3), respectively. Guangzhou and Shanghai have the relatively lower radon levels with 71.1 and 72.6 Bqm(-3). The annual effective dose by exposure to radon received by people working in these cities is concluded to be 1.6 mSv. The geological formation, coating level, decorating materials and ventilation situation all affect the radon concentration in underground buildings. The radon level in underground buildings has the lowest value in winter and the highest value in summer.     

The extremely high 137Cs inventory in the Sulu Sea: a possible mechanism

Large-volume seawater samples were collected in the Sulu and South China Seas and their (137)Cs activities were determined by gamma-ray spectrometry using a low background type high-purity Ge detector. Vertical distributions of (137)Cs activity showed an exponential decrease in the South China Sea, whereas a subsurface maximum at 200m depth and monotonic decrease below 300m were observed in the Sulu Sea. A significant difference in intermediate water (137)Cs activities in the 500-2000m depth was observed between the Sulu and South China Seas, i.e., the (137)Cs activities in the Sulu Sea were remarkably higher than those in the South China Sea. The difference in the (137)Cs inventory below 500m was approximately 1200Bqm(-2) between the Sulu and South China Seas. The (137)Cs total inventory of 3200Bqm(-2) in the Sulu Sea was 5.7 times higher than that expected from global fallout. A possible mechanism controlling this extremely high (137)Cs total inventory may be inflows of the (137)Cs rich water masses through the Luzon Strait, lateral transport across the Mindoro Strait into the Sulu Sea, and then subduction into the deep layer in the basin.     

中黄山水准高值异常变化原因分析

双山—李家庄断裂上的中黄山水准自2006年年底年出现持续大幅度的上升变化。结合当地降雨、地质条件和水库蓄水量的分析，认为2006年干旱是；}起水准大幅度上升的主导性因素。     

闭路循环应用于金属表面处理行业的环境影响分析──生命周期分析的实例

本研究应用生命周期分析（lifecycleanalysis）的方法，对瑞典某金属表面处理工厂采用闭路循环工艺后的环境影响进行了分析。分析证明：闭路循环确可降低重金属对空气和水的污染，但增加了对不可再生能源的消耗，因而在采用该工艺时应特别关注能源问题．以期得到最好的环境效益。     

Influences of sediment dessication on phosphorus transformations in an intertidal marsh: formation and release of phosphine

This study investigated the effects of sediment dewatering on the phosphorus transformations concerning about the production and emission of phosphine in the intertidal marsh of the Yangtze Estuary. The concentrations of matrix-bound phosphine ranged from 18.62-72.53 ng kg⁻¹ and 31.14-61.22 ng kg⁻¹ within the August and January exposure incubations, respectively. The responses of matrix-bound phosphine concentrations to sediment dessication demonstrate that the production (or accumulation) of matrix-bound phosphine significantly increased with water loss at the start of the emersion incubations. However, further dehydration inhibited the formation of matrix-bound phosphine in sediments. The significant correlations of matrix-bound phosphine with the organic-P bacteria abundance and alkaline phosphatase activities implicate that the production of matrix-bound phosphine within the dessication incubations was linked closely to the microbial decomposition of organic P. The emissions of phosphine generally decreased with sediment dewatering, with the fluxes of 7.51-96.73 ng m⁻² h⁻¹ and 5.34-77.74 ng m⁻² h⁻¹ over the exposure incubations of both August and January, respectively. Also, it is observed that the releases of phosphine during the entire exposure periods were affected not only by its production but also by sediment water and redox conditions.     

Effect of tetraconazole application on the soil microbial community

Tetraconazole is one of the most commonly used triazole fungicides in agricultural practice, and its continuous application poses a potential risk for non-target soil microorganisms. Therefore, the objective of this study was to evaluate the effect of tetraconazole at the field rate (T1, 0.33 mgkg^?1 of soil), three times the field rate (T3, 1.00 mgkg^?1 of soil) and 10 times the field rate (T10, 3.33 mgkg^?1 of soil) on the soil microorganisms. To ascertain this effect, the tetraconazole concentration and the microbial properties with potential as bioindicators of soil health (i.e. microbial biomass C, basal respiration, substrate-induced respiration, structure diversity and functional community profiling) were determined. The results showed that the degradation half-lives of tetraconazole varied from 69 to 87 days, depending on the three application concentrations. The microbial biomass C, basal respiration and substrate-induced respiration were inhibited, but they tended to recover at the end of the incubation when tetraconazole was applied at the recommended field rate. The ratios of the gram-negative to gram-positive (GN to GP) bacteria decreased, and the fungi to bacteria ratio increased after a temporal decrease on the seventh day. A principal component analysis of the PLFAs showed that tetraconazole application significantly shifted the microbial community structure on day 7. Different functional community profiles were observed, depending on the tetraconazole application rates. It was concluded that tetraconazole application decreases the soil microbial biomass and activity and changes the structures of the soil microbial community.     

含硫化氢油田地面工程设计实践与认识

文章分析了硫化氢(H2S)的危害,提出了含H2S油田地面工程设计思路。在长庆油田现有工艺流程的基础上,针对硫化氢的危害,通过采用地面工艺全流程密闭、选用抗硫工艺设备、管材等工艺技术,实现油田安全清洁生产,确保油田安全、高效开发。     

气升式内循环蜂窝陶瓷反应器高效快速修复地表水的研究

采用新型蜂窝陶瓷载体气升式内循环反应器(IAL-CHS)对受污染的城市地表水进行生物修复,该反应器能快速有效地修复受污染水体.考查了氨氮的变化历程、HRT与氨氮去除率间的关系,确定了最佳HRT为20 min.在HRT为20 min、接触反应时间仅为14 min条件下,该反应器对氨氮、TP、COD、TOC、浊度、UV254的去除率分别为86.7%～96.2%、4.5%～34.4%、15.5%～63.6%、5.8%～38.1%、9.4%～88.3%、3.8%～48.5%.