首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   14篇
  免费   2篇
  国内免费   5篇
安全科学   1篇
废物处理   3篇
环保管理   1篇
综合类   4篇
基础理论   7篇
污染及防治   5篇
  2023年   1篇
  2021年   1篇
  2020年   1篇
  2018年   1篇
  2015年   2篇
  2014年   2篇
  2013年   1篇
  2010年   1篇
  2008年   3篇
  2007年   1篇
  2006年   1篇
  2004年   1篇
  2002年   2篇
  2001年   1篇
  2000年   1篇
  1999年   1篇
排序方式: 共有21条查询结果,搜索用时 17 毫秒
11.
社会-生态系统如何响应全球环境变化已经被认为是当今自然资源管理中重点关注的方面之一,弹性理论为科学分析社会-生态系统中扰动和适应性的相互作用提供重要理论基础。在人地矛盾日益突出的今天,弹性作为自然界和人类系统一个有价值的特性,对其概念内涵进行分析并总结其评价的研究进展,具有重要的意义。在介绍弹性起源基础上,对弹性定义进行了剖析,对工程弹性、生态系统弹性以及社会-生态系统弹性进行解释。在此基础上,着重分析了弹性分别与脆弱性、适应性和可持续发展之间的区别与联系,并从评价框架、评价指标和评价工具等方面对弹性的定量评价与应用进行回顾。最后,从弹性内涵、定量评价和退化的社会-生态系统弹性修复实践3个方面对未来的发展趋势进行展望。  相似文献   
12.
甲胺磷生产废水处理试验研究   总被引:12,自引:0,他引:12  
提出三条处理甲胺磷生产废水的工艺路线:(1)胺化废水脱氨处理,甲基氯化物废水水解处理,然后混合生化处理;(2)胺化废水脱氨处理后与甲基氯化物原水混合一段生化处理;(3)胺化废水脱氨处理后与甲基氯化物原水混合二段生化处理。对影响废水脱氨、有机磷水解率和生化处理效果的各种因素进行了试验研究,分析了甲胺磷废水水解生成物,筛选出生化处理甲胺磷废水的优势菌种。  相似文献   
13.
Base-catalyzed dehydrochlorination of alpha-, beta-, and gamma-hexachlorocyclohexane (HCH) was examined at different pH and temperature conditions. No reaction was observed for beta-HCH under all tested conditions likely due to the fact that all chlorines are at the equatorial positions. Highly pH- and temperature-dependent reaction rates were observed for alpha- and gamma-HCH, and pentachlorocyclohexenes (PCCHs) and 1,2,4- and 1,2,3-trichlorobenzene (TCB) were detected as the intermediates and final products of the transformation of both alpha- and gamma-HCH. The pseudo-first-order rate constants of each step of the reactions were calculated at different T and pH conditions. For the first step, the rate constants were at approximately 0.0005 d-1 in solutions below pH 7.0, and increased by about an order of magnitude per pH unit from pH 7.01 to pH 12.02. The second-order reaction rate constants (kb) of this step were 3.57+/-0.03 and 3.19+/-0.19 M-1 d-1, respectively, and the associated activation energies (Ea) at pH 9.26 were 60.4+/-7.8 and 67.7+/-8.7 kJ mol-1, respectively, for alpha- and gamma-HCH. The rate constants for the formation of 1,2,3-TCB (k21) and 1,2,4-TCB (k22) were 0.0032+/-0.0001 d-1 and 0.051+/-0.003 d-1 from alpha-HCH, and 0.0017+/-0.0001 d-1 and 0.0041+/-0.0002 d-1 from gamma-HCH at pH 8.28 and 25 degrees C. Both k21 and k22 also showed an increase by about one order of magnitude per pH unit from pH 8.28 to pH 12.02. The Ea values were 64.4+/-6.8 and 88.8+/-5.2 kJ mol-1, respectively, for the formation of 1,2,4-TCB and 1,2,3-TCB from alpha-HCH, and 70.6+/-8.7 and 92.0+/-4.9 kJ mol-1, respectively, for the formation of 1,2,4- and 1,2,3-TCB from gamma-HCH at pH 9.26. Data provided by this study may be used for calculation of the percentages of the TCBs formed at different environmental conditions.  相似文献   
14.
SBR工艺去除模拟城市污水中双酚A的研究   总被引:1,自引:1,他引:0  
依次改变SBR系统(厌氧-好氧-缺氧模式)的水力停留时间(HRT)、好氧-缺氧段时间比以及污泥龄(SRT),并采用液相色谱法对系统双酚A(BPA)浓度进行了检测,从BPA去除的角度对SBR工艺进行了评估,同时对部分工艺运行参数进行了优化.结果表明,SBR工艺对BPA有较好的去除能力;在温度为20 ℃、充水比(SBR工艺1个周期中进入反应器的污水量与反应器有效容积之比)为50%的条件下,最佳的工艺运行参数为总HRT=480 min,SRT=25 d,厌氧、好氧、缺氧段HRT分别为90、150、180 min;好氧-缺氧段时间比为0.83,此时COD、TN和PO43--P的总去除率分别达到89%、69%和95%,BPA总去除率达到99%,其中厌氧、好氧、缺氧段BPA去除率分别占BPA总去除率的66%、32%和1%.BPA在上述SBR系统中的去除主要是通过厌氧段污泥吸附和好氧段的生物降解实现的.  相似文献   
15.
Environmental Science and Pollution Research - Considering the shortage of per capita water resources in China, the paper established a fractional order accumulated grey prediction model (FGM(1,1))...  相似文献   
16.
青藏高原SBR工艺动力学分析   总被引:1,自引:0,他引:1  
提出SBR工艺在充水期、反应期底物降解的动力学方程,并将动力学方程应用于青藏高原处理啤酒废水的SBR工艺中。求出的动力学参数值与工程实际运行能很好地吻合,表明建立的动力学模型的正确性和有效性,同时证明该工程采用的适合青藏高原气候环境特点的强化措施是必要的、可行的。  相似文献   
17.
The spatial variations of volatile organic compounds (VOCs) were characterized in the Village of Waterfront South neighborhood (WFS), a "hot spot" for air toxics in Camden, NJ. This was accomplished by conducting "spatial saturation sampling" for 11 VOCs using 3500 OVM passive samplers at 22 sites in WFS and 16 sites in Copewood/Davis Streets (CDS) neighborhood, an urban reference area located ~1000 m east of the WFS. Sampling durations were 24 and 48 h. For all 3 sampling campaigns (2 in summer and 1 in winter), the spatial variations and median concentrations of toluene, ethylbenzene, and xylenes (TEX) were found significantly higher (p < 0.05) in WFS than in CDS, where the spatial distributions of these compounds were relatively uniform. The highest concentrations of methyl tert-butyl ether (MTBE) (maximum of 159 μg m(-3)) were always found at one site close to a car scrapping facility in WFS during each sampling campaign. The spatial variation of benzene in WFS was found to be marginally higher (p = 0.057) than in CDS during one sampling campaign, but similar in the other two sampling periods. The results obtained from the analyses of correlation among all species and the proximity of sampling site to source indicated that local stationary sources in WFS have significant impact on MTBE and BTEX air pollution in WFS, and both mobile sources and some of the stationary sources in WFS contributed to the ambient levels of these species measured in CDS. The homogenous spatial distributions (%RSD < 24%) and low concentrations of chloroform (0.02-0.23 μg m(-3)) and carbon tetrachloride (0.45-0.51 μg m(-3)) indicated no significant local sources in the study areas. Further, results showed that the sampling at the fixed monitoring site may under- or over-estimate air pollutant levels in a "hot spot" area, suggesting that the "spatial saturation sampling" is necessary for conducting accurate assessment of air pollution and personal exposure in a community with a high density of sources.  相似文献   
18.
非均相催化臭氧氧化深度处理炼油废水   总被引:1,自引:0,他引:1  
采用非均相催化剂催化臭氧氧化处理炼油废水,考察了催化剂负载率、p H、催化剂投加量和臭氧投加量及反应时间对处理效果的影响。结果表明,组合工艺最佳工艺条件为:催化剂负载率2.1%、p H 9、催化剂投量80 g/L、臭氧投量8.1 mg/L、反应时间60 min,COD、石油类、NH3-N、硫化物和SS去除率分别为91.3%、92.7%、80.5%、34.5%和59%。处理炼油废水过程中组合工艺存在明显协同效应,协同因子为1.47。中间臭氧氧化和催化臭氧氧化在最优工艺条件下对炼油废水COD的降解均符合准一级动力学规律。基于叔丁醇的实验结果,结合降解动力学可以推测,降解炼油废水过程中非均相催化剂催化臭氧产生高活性羟基自由基是降解效率提高的主导因素。  相似文献   
19.
倪可  王利平  李祥梅  章滢 《化工环保》2014,34(2):176-180
采用浸渍沉淀法制备负载型金属催化剂,考察了载体种类、活性组分种类、活性组分配比(n(Fe2+)∶n(Mn2+))、浸渍液浓度(以Mn2+计)、煅烧温度和煅烧时间对催化剂性能的影响。实验结果表明:活性炭负载FexOy-MnOx型催化剂具有较高的活性;将在浸渍液浓度0.5 mol/L(以Mn2+计)、n(Fe2+)∶n(Mn2+)=1∶2、煅烧温度250 ℃,煅烧时间8 h条件下制备的催化剂用于印染废水(COD=584 mg/L、色度500倍)的处理,在臭氧流量0.8 L/min、废水pH 7、催化剂加入量40 g/L、反应时间60 min的条件下,印染废水COD的去除率为83.2%;该催化剂具有良好的稳定性,连续使用6次后的COD去除率仍可达到61.1%。  相似文献   
20.
响应面方法优化Fenton试剂处理甲萘酚废水   总被引:4,自引:0,他引:4  
利用响应面方法(RSM)对Fenton试剂处理甲萘酚废水工艺过程进行优化,考察了Fe2+浓度、H2O2浓度和初始p H 3种工艺条件对甲萘酚废水处理效果的影响,并提出Fenton试剂降解甲萘酚废水的数学模型及优化后的工艺参数。Fenton试剂降解甲萘酚废水的数学模型可以较好地模拟真实的曲面,方程的F值为24.90,相关系数(R2)为0.9573,调整相关系数(R2adj)为0.9188。通过优化得到最佳的工艺参数Fe2+浓度为0.89 g/L,H2O2浓度为0.79 g/L,p H为4.00。在此条件下,COD去除率的预测值为91.15%,与实测值90.78%接近。说明建立的模型能真实地反映各主要因素的影响,模型与实际情况吻合。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号