Effects of intercropping with floricultural accumulator plants on cadmium accumulation in grapevine

Environmental Science and Pollution Research - Grapevine (Vitis vinifera L.) intercropping with floricultural cadmium (Cd) accumulator plants (Helianthus annuus L., Cosmos sulphureus Cav., Cosmos...     

严格出厂检验确保产品质量

为贯彻落实国务院有关领导同志的批示精神，保障劳动者的安全和健康，根据国家安全生产监管总局办公厅“关于开展劳动防护用品专项监督检查的紧急通知”要求，劳防用品专项监督检查工作正在全国范围内深入开展。     

SBR法降解有机物规律的研究

本研究是以处理啤酒废水的试验为基础展开的。试验结果进一步验证了SBR法具有简易,快速、低耗等优点。除此之外,还得出以下结论:增加间歇反应时起始污泥浓度可以提高处理效率或减少反应时间;非限制曝气方式耐冲击负荷,需氧均匀,能缩短反应周期;间歇反应中微生物细胞的合成代谢占主导地位,对氮与磷的需要量大于传统的理论值。本文还指出SBR法是很适合我国国情的一种废水处理工艺,应当加强对它的研究和推广应用。     

填料塔应用于烟道气治理时设计中应注意的问题探讨

论述了填料塔烟道气治理装置的填料层及塔内件的设计,并和传统的塔型尺寸及各种参数进行了比较。     

不同粒度飞灰中16种微量元素的含量分布

研究了不同粒级的燃煤飞灰中的Ｂａ、Ｂｅ、Ｃｄ、Ｃｒ、Ｃｕ、Ｈｇ、Ｌｉ、Ｍｎ、Ｎｉ、Ｐｂ、Ｓｒ、Ｔｉ、Ｖ、Ｚｎ、Ｚｒ元素的含量分布,煤中元素的含量比及富集因子。     

微污染水源水净化新技术

介绍了近年来出现的纳滤膜,预臭氧化及新型生物反应器（膜生物反应器和电生物反应器）处理微污染水源水的最新技术动态。对相关机理进行了归纳总结。     

负载型金催化剂用于室温下CO的消除

从催化活性、抗潮湿、抗硫中毒、稳定性等方面考察了负载型金催化剂对于ＣＯ氧化反应的性能。筛选出的２－３催化剂可在－２２℃下完全消除ＣＯ，并且在催化活性、抗潮湿、抗硫中毒、稳定性等方面具有现行催化剂无法比拟的优点。     

Environmental contamination of mercury from Hg-mining areas in Wuchuan, northeastern Guizhou, China

Total Hg and methyl-Hg were evaluated in mine wastes, soils, water, and vegetations from the Wuchuan Hg-mining areas, Guizhou, China. Mine wastes contain high total Hg concentrations, ranging from 79 to 710 microg g(-1), and methyl-Hg from 0.32 to 3.9 ng g(-1). Total Hg in soil samples range from 0.33 to 320 microg g(-1) and methyl-Hg from 0.69 to 20 ng g(-1). Vegetations present a high average total Hg concentration of 260 ng g(-1), which greatly exceeds the maximum Hg concentration of 20 ng g(-1) recommended by the Chinese National Standard Agency for food sources. The rice samples contain elevated methyl-Hg concentrations, ranging from 4.2 to 18 ng g(-1). Stream water collected from Hg-mining areas is also contaminated, containing Hg as high as 360 ng l(-1), and methyl-Hg reaches up to 5.7 ng l(-1). Data indicate heavy Hg-contaminations and significant conversion of methyl-Hg in the study areas.     

Accumulation and elimination of aqueous and dietary silver in Daphnia magna

The dissolved uptake, dietary assimilation, and efflux of Ag in a freshwater cladoceran, Daphnia magna, were measured under different laboratory conditions. The dissolved uptake rate of Ag was proportional to the ambient Ag concentration, but the accumulation was highly variable due to the sorption of Ag onto the daphnid bodies. The ambient Na(+) but not the ambient K(+) concentration significantly decreased the dissolved uptake of Ag, suggesting a competitive uptake of Ag(+) with Na(+). The dietary assimilation efficiencies (AEs) of Ag are dependent on the concentration of the algal food available to D. magna. The AE was as low as 2% when the food concentration reached the saturation levels. In contrast, the Ag concentrations in the algae did not significantly affect the Ag AE in D. magna. The efflux rate constant of diet-incorporated Ag was twice that through dissolved uptake. The elimination of Ag was further separated into different compartments (excretion, egestion, molting, and reproduction) in the juveniles and adults after accumulation from dissolved and dietary sources. Regeneration into the dissolved phase was the predominant pathway by which the incorporated Ag was lost from D. magna, regardless of the exposure pathway. In contrast to the essential metals or Hg, there was minimal maternal transfer of Ag from the mothers to the offspring. By employing the biokinetic model, we further showed that water is a dominant pathway for Ag accumulation in D. magna. Trophic transfer is less significant primarily because of the low Ag AE when the food concentration reached the saturation levels.     

Organochlorine pesticides in soil profiles from Tianjin, China

Soil cores were collected from soils at five sites in Tianjin area for the determination of hexachlorocyclohexane isomers (HCHs, including alpha-HCH, beta-HCH, gamma-HCH and delta-HCH), dichlorodiphenyltrichloroethane and metabolites (DDXs, including p,p'-DDT, p,p'-DDE and p,p'-DDD) and total organic carbon (TOC). The levels and vertical distributions of HCHs and DDXs are studied. Results show that the application of pesticides in the past years was the major contributor of HCHs and DDXs accumulation in the sampling areas. Significant positive correlations were seen between the residual and application amounts of HCHs and DDXs. Wastewater irrigation did not bring a significant contribution of HCHs or DDXs into the soils. HCHs and DDXs concentrations peak at the surface and decline in soil profile with depth, while fluctuations were observed in the plow layers of some cultivated soils caused by frequent cultivation activities and batch irrigation. Positive correlations were observed between the contents of TOC and HCHs and DDTs. Although the amounts of HCHs application in all sampling sites are larger than DDXs, at surface and near surface layers of most sampling sites, the concentrations of summation operatorHCHs are lower than summation operatorDDXs. The composition of DDXs in the applied pesticides and sampled soils indicates that there is no recent DDT input at the sample areas.