排序方式: 共有14条查询结果,搜索用时 0 毫秒
1.
Ruiqiang?YangEmail author Ting?Xie Handong?Yang Simon?Turner Guangjian?Wu 《Environmental geochemistry and health》2018,40(1):303-312
Sediment cores from four lakes across the Tibetan Plateau were used as natural archives to study the time trends of organochlorine pesticides (OCPs). The total concentrations of dichlorodiphenyltrichloroethane (ΣDDT) and hexachlorocyclohexane isomers (ΣHCH) were in the range of 0.04–1.61 and 0.08–1.88 ng/g based on dry weight (dw), while the input fluxes were in the range of 0.3–236 and 0.7–295 pg/cm2/y in the core sediments, respectively. The input fluxes of ΣDDT and ΣHCH generally peaked in sediment layers corresponding to the 1970s–1990s and peaked in top sediment layers. The ratio of α/γ-HCH decreased in the top layer sediments, implying that the contribution of lindane (pure γ-HCH) has been increasing in recent years. In addition, the ratio of o,p′-DDT/p,p′-DDT increased significantly over the last 15–20 years, suggesting that dicofol (characterized by high ratio of o,p′-DDT/p,p′-DDT about 7.0) has recently become a relatively more important source of DDT compared to technical DDT itself. The time trends of OCPs recorded in lake sediments examined the impact on such remote alpine regions by human activities. 相似文献
2.
3.
采用无机陶瓷超滤膜和低浓度阴离子表面活性剂十二烷基苯磺酸钠(SDBS)处理亚甲基蓝(MB)模拟废水,考察了废水中SDBS、MB浓度及废水pH对超滤过程的影响.实验结果表明:SDBS浓度影响MB在最大吸收波长处的吸光度值;当废水中SDBS浓度为1.20 mmol/L(即25℃时的临界胶束浓度)、废水中MB浓度为1.00 mmol/L、废水pH为9.0时,超滤效果最好;在此条件下,透过液中SDBS浓度和MB浓度分别为0.06 mmoL/L和0.01 mmol/L,MB的截留率为99.2%,膜通量为309.6 L/(m~2·h).SDBS对MB超滤过程的强化机理主要为MB与SDBS形成结合体析出及SDBS胶束的增溶作用. 相似文献
4.
基于ALOHA软件模拟环氧丙烷储罐泄漏事故 总被引:1,自引:0,他引:1
环氧丙烷是一种高危险性的基本有机化工原料,储罐发生泄漏时会引发人员中毒、闪火、蒸气云爆炸、池火灾以及BLEVE等5类事故,采用ALOHA软件对这5类事故进了模拟计算,定量得出了各类事故的活性危害范围。其中,人员中毒和BLEVE火球热辐射的危害范围最大,其次是闪火和蒸气云爆炸,最后是池火灾。研究结果可以为环氧丙烷储罐泄漏事故救援提供有效的技术支持。 相似文献
5.
Xu Guangjian Yang Eun Jin Lee Youngju Kang Sung-Ho 《Environmental science and pollution research international》2020,27(31):38769-38775
Environmental Science and Pollution Research - Multivariate dispersion has proven to be a broad β-diversity measure that shows the heterogeneity of environmental conditions. The dispersion... 相似文献
6.
7.
针对135 MW循环流化床锅炉输煤系统碎煤机室袋除尘器除尘效果差的实际问题,对布袋除尘器进行合理改造,降低了环境粉尘浓度,改善了车间生产环境,保证了输煤系统的正常运行和现场文明生产。 相似文献
8.
研究了在酸性介质中,亚硝酸根离子与番红O偶联反应的机理,并作为光度分析新方法应用于测定亚硝酸根离子,研究表明,在520nm处,试剂空白同试液吸光度的差值与亚硝酸根离子的含量在20-500μg/L范围内的成线性关系。方法用于土壤,环境水样中亚硝酸根离子的测定,结果满意。 相似文献
9.
10.