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41.
重点生态功能区以保持并提高生态产品供给能力为主体功能定位,区内自然环境敏感性和脆弱性突出,研究其人类活动过程中的环境污染源排放特征与空间管控模式,对科学协调保护与利用、切实加强重点生态功能区环境保护和治理水平具有重要意义.以青藏高原重要生态安全屏障区藏东南为例,基于环境污染源的固体废弃物、水体污染物和大气污染物排放强度的分类估算与空间特征解析,探讨面向污染源排放强度和多尺度管控精度的分级空间管控方案.研究结果表明:藏东南环境污染源的排放强度整体较低,雅鲁藏布江和雅尼河谷地因人类生产生活活动密度较大,其污染物排放量显著高于其他区域;在重点生态功能区应建立由7个二级类和21个三级类构成的环境污染源空间管控体系,重点管控以城镇居住区和工矿业生产空间为主的"点状"胁迫、以交通运输场所和人文游憩空间为主的"线状"胁迫、以农业种植区和畜禽养殖区为主的"面状"胁迫;针对藏东南各类环境污染源的空间耦合及交互特征,提出城乡生活集聚型、农牧业生产集聚型和休闲旅游集聚型3种典型区,依次制定"分级处理+资源利用"、"源头减排+就地消纳"、"实时动态监控+绿色设施营造+游憩利用规范"的差异化空间管控模式. 相似文献
42.
Desorption kinetics of neutral hydrophobic organic compounds from field-contaminated sediment 总被引:3,自引:0,他引:3
The chemical release rates from a field-contaminated sediment (Lake Charles, LA) using Tenax desorption were studied. Two dichlorobenzenes (m-, p-), hexachlorobutadiene, and hexachlorobenzene were investigated. Contrary to reports that sorption rates are inversely related to K(OW), the slow desorption rates were found to be similar for the four compounds. The data were modeled by a two-compartment irreversible adsorption and radial diffusion model. Desorption kinetics from the first irreversible compartment can be modeled by radial diffusion and assume an irreversible adsorption constant and soil tortuosity of 4.3. The desorption half-life is approximately 2-7 days. Desorption from the second irreversible compartment is very slow (half-life of approximately 0.32-8.62 years) presumably caused by entrapment in soil organic matter that increases the constrictivity of the solid phase to chemical diffusion. From the kinetic data, it is deduced that the diffusion pore diameter of the second irreversible compartment is approximately equal to the critical molecular diameter. The mass of chemicals in this highly constrictive irreversible compartment is approximately one-fourth of the maximum irreversible, or resistant, compartment. The slow kinetics observed in this study add additional support to the notion that the irreversibly sorbed chemicals are 'benign' to the environment. 相似文献
43.
从保定市某印染厂曝气池废水中分离到一株对染料直接大红GBE有高效脱色效果的菌株HD 1,经鉴定 ,该菌为沙门氏菌属 (Salmonella) ,在 2 5— 3 7℃都有较高的脱色率 ,最佳脱色温度为 3 7℃ ,在pH 6— 8范围内对染料具有明显的脱色效果 ,最佳脱色 pH值为 7.0 ,氧气对脱色具有一定的抑制作用。染料脱色产物的紫外 -可见光谱分析表明 ,可见光区 488nm处的吸收峰完全消失 ,而在紫外区出现了两个吸收峰 相似文献
44.
The first example of a ruthenium sensitizer (TUS-22) having a natural dye, bisdemethoxycurcumin, as a ligand has been synthesized. The dye-sensitized solar cell based on this novel dye showed 5.8% conversion efficiency under AM 1.5 (100 mW/cm2) irradiation. 相似文献
45.
46.
为了系统研究聚合氯化铝(PAC)和聚丙烯酰胺(PAM)对生物造粒流化床颗粒污泥生理生态的影响,对投加PAC或PAM后活性污泥的特性和硝化菌群的空间分布进行了对比研究,同时考察了投加混凝剂后的污染物去除效果.结果表明,与不投加混凝剂相比,投加PAC后,运行60 d时反应器中混合液悬浮固体(MLSS)、混合液挥发性悬浮固体(MLVSS)浓度分别提高了73%、29%;通过平板计数法计算结果可知,未投加混凝剂、投加PAC、投加PAM的反应器中微生物的增长是非常稳定的,投加PAC或PAM都促进了细菌的生长和繁殖;荧光原位杂交鉴定结果表明,各个反应器中亚硝化菌(AOB)或硝化菌(NOB)所占比例均基本相当,且AOB数量均略高于NOB数量;投加PAC或PAM都能够提高COD的去除率;投加PAC可大大提高TP的去除率;3个反应器中各种形态氮的去除效果非常接近,脱氮主要靠硝化菌群的生物降解作用,投加PAC或PAM对微生物的硝化作用没有抑制. 相似文献
47.
Hironobu Sugiyama 《Journal of the American Water Resources Association》1996,32(3):491-497
ABSTRACT: It is important to extract and assess low flow recession characteristics for water resources planning in the upper reaches of streams. However, it is very difficult to express synthetically the low flow recession characteristics for a stream flow. In this paper, first a new method of constructing the master recession curve based on the exponential expression is proposed and applied with the restriction that there are no regulation or diversion structures in the upper reaches above the measurement station. Daily precipitation and stream flow were used for the analysis. Second, analysis for a recession constant was conducted and the relationship between the recession constant and low flow and/or geology was qualitatively examined. In conclusion, the application of the proposed method indicated that it is objective and useful for constructing the master recession curve. It became apparent that the recession constant of a master recession curve may be defined as the total index of low flow characteristics. In addition, it was found that baseflow value increases in the order of Paleozoic, Mesozoic, Tertiary, and Quaternary. 相似文献
48.
This study examined the levels of seven heavy metals (namelyzinc, copper, cadmium, chromium, lead, manganese and iron) andtheir associations with magnetic properties in playground dustof Hong Kong. Results showed that the playground dust containedhigh concentrations of Zn (mean = 1883 g g-1), Cu(mean = 143 g g-1) and Cr (mean = 263 g g-1).Qualitative examination of dust samples under microscope indicated local traffic as one of the important pollutant sources. Magnetic measurements indicated that these anthropogenicpollutants mainly consisted of coarse-grained multidomain (MD) ferrimagnetic minerals. Superparamagnetic (SP), stable single domain (SSD) ferrimagnetic grains and non-ferrimagnetic mineralswere present in relatively small amounts. Significant correlations between heavy metals and various magnetic parametersindicated a strong affinity of heavy metals to magnetic minerals hence pointed out the potential of magnetic properties for simpleand rapid proxy indications of heavy metal pollution in playground dust. 相似文献
49.
50.
Sakai K Kamijima M Shibata E Ohno H Nakajima T 《Journal of environmental monitoring : JEM》2006,8(11):1122-1128
2-Ethyl-1-hexanol is a possibly causative chemical in sick building symptoms, although 2-ethyl-1-hexanol has received little attention as a hazardous substance in studies on indoor air pollution. Airborne 2-ethyl-1-hexanol concentrations were measured from 2002 to 2004 in 99 rooms of 42 non-domestic buildings in Nagoya, Japan. The diffusive sampling method is effective for the measurement of a low level of 2-ethyl-1-hexanol in indoor air. The geometric mean (geometric standard deviation) of 2-ethyl-1-hexanol concentrations was 16.5 (5.4) microg m(-3) in indoor air and 1.9 (2.2) microg m(-3) in outdoor air. The maximum concentration of 2-ethyl-1-hexanol in indoor air and outdoor air was 2709 microg m(-3) and 12.4 microg m(-3), respectively. Fewer rooms in a small number of new buildings showed high concentrations of 2-ethyl-1-hexanol, while low concentrations were observed in many rooms of these buildings as well as the other new buildings. The room-to-room concentrations of 2-ethyl-1-hexanol in each building exhibited a wide variation. The geometric mean of the 2-ethyl-1-hexanol concentrations was significantly higher for indoor air than for outdoor air (p < 0.01). The correlation of the 2-ethyl-1-hexanol concentrations between indoor and outdoor air was not significant. Mechanical ventilation was effective in the temporary reduction of indoor 2-ethyl-1-hexanol level. These results suggest that the predominant source of 2-ethyl-1-hexanol was indoor areas. 相似文献