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991.
娜日思 《环境与发展》2020,(2):81-81,83
我国作为世界第二大经济体,也是全球第一大发展中国家,对于石油的需求也是很大的。石油作为不可再生资源,虽然我国的炼油技术发展也有了非常显著的提升,但是炼油过程产生和消耗所伴随的环境问题也越来越大。为了解决炼油过程中所带来的环境问题,我们必须采取有效的措施来提升环保性能,依托节能和环保,以保证炼油工业的长期、高质量发展。  相似文献   
992.
常用的机内测试(BIT)方式主要包括加电BIT、周期BIT和维护BIT,本文针对目前行业内缺少分别确定装备三种BIT指标方法的问题,提出一种考虑可用性和任务成功性的直升机机内测试需求建模和指标确定方法。将装备的可用度和任务成功性指标作为约束条件,构造面向可用度的装备加电和维护BIT测试性需求模型和考虑任务成功性的周期BIT指标需求模型,同时将三种BIT的设计代价作为限制,综合确定三种BIT的指标。最后以某型直升机为示例,验证所提方法的有效性。  相似文献   
993.
本研究分别以NaOH和NH_3·H_2O为矿化剂,Ce(NO_3)_3·6H_2O为铈源,采用水热法成功制备两种新型纳米二氧化铈材料(CeO_2-Na与CeO_2-N).XRD、FESEM、Raman和EPR等表征手段以及非均相类Fenton降解盐酸四环素(TCH)性能分析结果表明,与CeO_2-N相比,纳米CeO_2-Na催化剂具有更大的比表面积和更高的表面氧空位浓度,其对TCH的催化性能也优于CeO_2-N.在TCH初始浓度为100 mg·L~(-1),催化剂投加量为0.7 g·L~(-1)和H_2O_2投加量为10 mmol·L~(-1)的条件下,CeO_2-Na/H_2O_2/TCH体系对TCH的去除率达86%,通过简单的热处理可以恢复催化剂的催化活性.TCH的降解机理研究表明,该非均相催化体系中起主要作用的是O~-_2·自由基.本研究为纳米氧化铈催化剂的制备及其非均相类Fenton的应用提供一定的技术和理论参考.  相似文献   
994.
• Superior catalytic activity observed for o-chlorophenol oxidation on Co2MgAlO. • The reducibility, oxygen species and basicity influenced catalytic activity. • The organic by-products were generated in o-chlorophenol catalytic oxidation. A cobalt-based hydrotalcite-like compound was prepared using a constant-pH coprecipitation method. Cobalt-transition metal oxides (Co2XAlO, X= Co, Mg, Ca and Ni) were investigated for the deep catalytic oxidation of o-chlorophenol as a typical heteroatom contaminant containing chlorine atoms. The partial substitution of Co by Mg, Ca or Ni in the mixed oxide can promote the catalytic oxidation of o-chlorophenol. The Co2MgAlO catalyst presented the best catalytic activity, and could maintain 90% o-chlorophenol conversion at 167.1°C, compared only 27% conversion for the Co3AlO catalyst. The results demonstrated that the high activity could be attributed to its increased low-temperature reducibility, rich active oxygen species and excellent oxygen mobility. In the existence of acid and base sites, catalysts with strong basicity also showed preferred activity. The organic by-products generated during the o-chlorophenol catalytic oxidation over Co2MgAlO catalyst included carbon tetrachloride, trichloroethylene, 2,4-dichlorophenol, and 2,6-dichloro-p-benzoquinon, et al. This work provides a facile method for the preparation of Co-based composite oxide catalysts, which represent promising candidates for typical chlorinated and oxygenated volatile organic compounds.  相似文献   
995.
减排N2O对控制地球温室效应和保护人类健康具有重要的意义。综述了有关分离纯化N2O的技术及N2O回收利用于芳烃氧化制苯酚的研究进展,介绍了N2O的热分解及催化分解等减排技术的研究成果。指出:采用N2O直接氧化芳烃制苯酚技术需要解决的技术关键是开发高选择性的催化剂;催化分解是目前可行的N2O减排技术,而制备高活性且抗O2、水蒸气及硫化物干扰的催化剂是今后的研究热点。  相似文献   
996.
某甲醇制高清洁燃油企业通过技术经济比选,确定采用"UASB+水解酸化+PACT+生物接触氧化+焦炭吸附+臭氧氧化"工艺处理生产、生活及实验、地面冲洗混合废水。运行结果表明,COD,BOD,SS,NH3-N平均质量浓度分别为49,8,4,2 mg/L,达到《污水再生利用工程设计规范》(GB 50335—2002)中工业循环冷却水补充水水质标准,回用后每年可节约用水约47.3万t,实现了环境效益与经济效益双赢。  相似文献   
997.
兽药在保障动物健康、提高畜禽产品质量尤其在畜牧业集约化发展等方面起着至关重要的作用,然而兽药和饲料添加剂的大量使用成为生态环境污染和人体健康损害的一个重要因素。研究表明许多抗生素类和激素类兽药是典型的环境内分泌干扰物,通过多种方式干扰生物体雄激素、雌激素、甲状腺激素等内分泌过程,产生内分泌干扰效应。本文介绍了典型兽药的污染现状及其内分泌干扰效应研究最新进展;以环境内分泌干扰物的最新研究方法为基础,较全面地评述了可用于兽药类内分泌干扰物的快速筛选、检测及评价方法,并对该领域未来研究提出了展望和建议,以期为环境和农业等管理部门制定兽药的使用、排放、管理政策提供科学依据。  相似文献   
998.
Dissolved organic matter (DOM), as the most active organic carbon in the soil, has a coherent affinity with heavy metals from inherent and exogenous sources. Although the important roles of DOM in the adsorption of heavy metals in soil have previously been demonstrated, the heterogeneity and variability of the chemical constitution of DOM impede the investigation of its effects on heavy metal adsorption onto soil under natural conditions. Fresh DOM (FDOM) and degraded DOM (DDOM) from sugarcane rind were prepared, and their chemical properties were measured by Fourier-transform infrared spectrometry (FTIR), excitation-emission matrix (EEM) fluorescence spectroscopes, nuclear magnetic resonance (NMR), and molecular weight distribution (MWD). They were also used in batch experiments to evaluate their effects on the adsorption of Cu(II) onto farmland red soil. Based on our results, the chemical structure and composition of DDOM greatly varied; compared with FDOM, the C/O ratio (from 24.0 to 9.6%) and fluorescence index (FI) (from 1.4 to 1.0) decreased, and high molecular weight (>10 kDa) compounds increased from 23.18 to 70.51%, while low molecular weight (<3 kDa) compounds decreased from 56.13 to 12.13%; aromaticity and humification degree were markedly enhanced. The discrepancy of FDOM and DDOM in terms of chemical properties greatly influenced Cu(II) adsorption onto red soil by affecting DOM-Cu(II) complex capacity. The FDOM inhibited the adsorption of Cu(II), while DDOM promoted adsorption, which was significantly influenced by soil pH. Maximum adsorption capacity (Q m) was 0.92 and 5.76 mg g?1 in the presence of FDOM and DDOM, respectively. The adsorption process with DDOM could be better described by the Langmuir model, while that with FDOM was better described by the Freundlich model. The impacts caused by the dynamic changes of the chemical properties of DOM under natural conditions should therefore be considered in the risk assessment and remediation of soils contaminated with heavy metals.  相似文献   
999.
This study aims to examine the effect of short-term changes in the concentration of particulate matter of diameter ≤2.5 µm (PM2.5) and ≤10 µm (PM10) on pediatric hospital admissions for pneumonia in Jinan, China. It explores confoundings factors of weather, season, and chemical pollutants. Information on pediatric hospital admissions for pneumonia in 2014 was extracted from the database of Jinan Qilu Hospital. The relative risk of pediatric hospital admissions for pneumonia was assessed using a case-crossover approach, controlling weather variables, day of the week, and seasonality. The single-pollutant model demonstrated that increased risk of pediatric hospital admissions for pneumonia was significantly associated with elevated PM2.5 concentrations the day before hospital admission and elevated PM10 concentrations 2 days before hospital admission. An increment of 10 μg/m3 in PM2.5 and PM10 was correlated with a 6% (95% CI 1.02–-1.10) and 4% (95% CI 1.00–1.08) rise in number of admissions for pneumonia, respectively. In two pollutant models, PM2.5 and PM10 remained significant after inclusion of sulfur dioxide or nitrogen dioxide but not carbon monoxide. This study demonstrated that short-term exposure to atmospheric particulate matter (PM2.5/PM10) may be an important determinant of pediatric hospital admissions for pneumonia in Jinan, China.

Implications: This study demonstrated that short-term exposure to atmospheric particulate matter (PM2.5/PM10) may be an important determinant of pediatric hospital admissions for pneumonia in Jinan, China, and suggested the relevance of pollutant exposure levels and their effects. As a specific group, children are sensitive to airborne particulate matter. This study estimated the short-term effects attribute to other air pollutants to provide references for relevant studies.  相似文献   

1000.
酶抑制法检测蔬菜中的有机磷农药   总被引:6,自引:0,他引:6  
对新型酶抑制检测蔬菜中有机磷农药残留量的方法进行了研究,介绍了胆碱酯酶的提取、纯化方法,以及用粗酶和纯酶检测蔬菜中有机磷农药残留量的测定效果,确定了最佳实验条件。对样品的预处理方法进行了改进,得出该法的检测限为1mg/L,对甲基对硫磷等几种常用农药的加标回收率为90.4%~112%,相对标准偏差为1.06%~9.83%,表明三项评价指标均符合全国农药残留科研协作组对农药残留分析方法的基本要求。  相似文献   
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