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1.
DevelopmentoftheprocedureforthestabilizationofrainwatersamplesYuanZhongxin;Chung-ShinYuan(DepartmentofChemicalEngineeringNati...  相似文献   

2.
SeaNine 211, with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) being the biocidal ingredient, is a widely-used antifouling agent to deter the undesirable biofouling phenomenon. It is commercially promoted as an environmentally acceptable antifoulant mainly due to its claimed rapid degradation in marine environment. However, increasing researches document varying degradative kinetics in different environments, proving that SeaNine 211 is actually not degraded equally fast around the world (half-life between < 1 day and 13.1 days). Large-scale application of SeaNine 211 in antifouling coatings has also caused global contamination of marine environment in various compartments. For example, accumulation of SeaNine 211 is detected as high as 3700 ng/L in Spanish seawater and 281 ng/g dry weight in Korean sediment. Considering that SeaNine 211 is highly toxic against non-target marine organisms, environmental risk assessment finds that most marine organisms are endangered by SeaNine 211 in worst-case scenario. Its endocrine disrupting and reproductive impairing effects at environmentally worst-case concentrations further constitute a long-term threat to the maintenance of population stability. Therefore, in the light of the varying degradability, environmental pollution and high toxicity, especially the endocrine disruption, SeaNine 211 as an antifouling agent is likely to cause non-negligible damages to the marine ecosystem. There is an urgency to perform a systematic ecological risk assessment of SeaNine 211 to prevent the potential impacts on the health of marine environment. A regular monitoring also becomes necessary to place the usage of antifouling biocides under control.  相似文献   

3.
Theresearchofbelow-cloudscavengingofrainwaterinGuilinCityBaiYuhua;YaoRongkui;LiXin;TangXiaoyan(TheDepartmentofTechnicalPhysie...  相似文献   

4.
A field enhanced flow reactor using bias assisted photocatalysis was developed for bacterial disinfection in lab-synthesized and natural waters. The reactor provided complete inactivation of contaminated waters with flow rates of 50 m L/min. The device consisted of titanium dioxide nanotube arrays, with an externally applied bias of up to 6 V. Light intensity, applied voltage, background electrolytes and bacteria concentration were all found to impact the device performance. Complete inactivation of Escherichia coli W3110(~ 8 × 10~3CFU/m L) occurred in 15 sec in the reactor irradiated at 25 m W/cm~2 with an applied voltage of 4 V in a 100 ppm NaCl solution. Real world testing was conducted using source water from Emigration Creek in Salt Lake City, Utah. Disinfection of natural creek water proved more challenging, providing complete bacterial inactivation after 25 sec at 6 V. A reduction in bactericidal efficacy was attributed to the presence of inorganic and organic species, as well as the increase in robustness of natural bacteria.  相似文献   

5.
The status of biological criteria in state and federal water quality programs suggest that the majority of North American resource types have at least a single multimetric index developed. Large rivers, wetlands, and lakes are in the process of being studied and reference conditions are being developed but have primarily been developed for the Midwest and Northeastern United States. Biological criteria can include a variety of biological indicators ranging from multimetric indices, univariate indices, standard zoological and botanical indicators, and predictive models. The use of biological models to predict local conditions can result in a variety of spatial scales that biological criteria can address. Biological criteria will be applied as a measure of water resource condition, as biological restoration goals, for enforcement and compliance, for establishing baseline for Natural Resource Damage Assessments (NRDA), for formulating predictive models, and by the Environmental Protection Agency (EPA) for meeting the Government Performance and Results Act Goal 2b.  相似文献   

6.
随着我国社会经济的发展,城市初期雨水污染负荷占城市河道污染负荷比例不断增大。针对该问题,通过模拟中试试验研究了滤坝系统对城市初期雨水的净化效果。结果表明:以沸石、石灰石、海绵铁和火山岩为主要填料的滤坝系统对CODCr、SS、$NH_{4}^{+}$-N、TN和TP都有较好的去除效果,平均去除率分别为84.69%、89.65%、25.66%、24.46%和50.06%。滤坝系统削减污染物的主要机理是填料的物理截留和吸附、化学吸附及海绵铁的内电解反应。  相似文献   

7.
An investigation was made to determine the feasibility of using the fiber of Rux (Calotropis gigantea), a common wild plant in Thailand, to make textile fabric. It was found that a mixture of Rux with cotton, as well as a mixture of Rux with synthetic fibers such as rayon or polyester, could be used to make textile fabrics of reasonable quality. As Rux is a weed growing everywhere without requirements for fertilizers and pesticides, the adoption of Rux as a source of fiber for the textile industry could bring large areas of presently unused marginal land under cultivation and might reduce the energy input to farming. Such a development could lead to a higher net income for farmers, as well as creating a new cottage industry to provide another source of income for the rural people of the third world.  相似文献   

8.
针对城市雨水管网沉积物中抗生素抗性基因(ARGs)污染特性尚不清楚的问题,本研究选择南京江北新区3种不同功能区(文教区、交通区及商业区)分流制雨水管网沉积物作为研究对象,考察了各功能区雨水管网沉积物中细菌耐药性,分析了β-内酰胺类和四环素类两类典型ARGs的组成种类及其相对丰度差异,重点探讨了上述典型ARGs在不同粒径颗粒中的分布特征.结果表明,各功能区可培养细菌总数大小顺序为商业区>文教区>交通区,而携带典型ARGs的耐药菌(ARB)相对含量大小顺序却为文教区>商业区>交通区;交通区的典型ARGs相对丰度高于文教区和商业区1个数量级;随着干期长度的增加,各功能区雨水管网沉积物中典型ARGs种类及相对丰度均有不同程度的减少;随着颗粒粒径的减小,文教区雨水管道沉积物中典型ARGs的丰度变化不大,交通区的雨水管道沉积物中典型ARGs的丰度则呈增加趋势,而商业区的无明显规律;粒径较小的颗粒中可移动遗传因子(MGEs)对ARGs的分布影响更大,且以<75μm粒径段颗粒中的最明显(相关系数为0.874).  相似文献   

9.
The potential biomass energy that can be derived from the harvest of rice crop residues is calculated for three methods of crop production. The potential energy available amounts to 3.70 × 1010 J ha?1 year?1 for traditional methods, 7.93 × 1010 J for the labor-intensive and 8.36 × 1010 J for the capital-intensive methods. The net energy benefits available for cooking, heating and biogasification are calculated on a per hectare basis taking into account the costs of collection, transportation and processing. The amounts of energy available for cooking and heating range from 3.70 × 109 to 8.33 × 109 J ha?1, and the amounts of energy for methanol use range from 1.85 × 109 to 4.17 × 109 J ha?1 year?1.The ecological problems associated with soil erosion, nutrient loss and pesticide use are evaluated in terms of the compensatory energy costs involved, and the resultant net energy balance for each method of rice production is calculated. The net energy available per hectare for the traditional method is 3.43 × 1010 J, for the labor-intensive method, 7.25 × 1010 J and for the capital-intensive method, 7.02 × 1010 J. The harvest of rice crop residues in the developing world could provide up to 5.80 × 1018 J year?1.The use of rice crop residues is investigated within the context of the rural village energy system. The prospects for the use of rice crop residues are evaluated in relation to alternative energy sources and it is concluded that regional residue harvest programs should be implemented cautiously, integrating soil management and environmental planning procedures where appropriate.  相似文献   

10.
The synchronous fluorescence spectroscopy of three polymiclear aromatic hydrocarbons was studied. It was shown that the specific Δλ of the spectra were 10nm for benzo(k) fluoranthene, 25 nm for benzo(a) pyrene, and 40 nm for pyrene. The peaks of the spectra were at 407, 404, and 373 nm for the three chemicals, respectively. Benzo(k) fluoranthene, benzo(a) pyrene, and pyrene in the urine samples from smokers were identified by high pressure liquid chromatography combined with the synchronous fluorescence spectroscopy.  相似文献   

11.
运用生态学原理设计绿色建筑小区已逐渐成为潮流,节水与水资源利用的问题正日益受到关注。绿色建筑小区雨水资源化综合利用技术集成优化了小区雨水收集与分散处理系统、雨水集中收集与处理系统、雨水渗透系统等技术,具有投资省、处理效果好、管理方便等优点,适合为今后的绿色建筑小区雨水资源化综合利用建设参考。  相似文献   

12.
This article describes a conductometric bi-layer based bienzyme biosensor for the detection of proteins as a marker of organic matter in rivers. Proteins were chosen to be used as indicators of urban pollution. The working mechanism of the bienzyme biosensor is based on the enzymatic hydrolysis of proteins into several fractions (peptides and amino acids), which results in a local conductivity change depending of the concentration of proteins. In this work, we began with the optimization of biosensor response using bovine serum albumin (BSA) as standard protein. For this objective seven enzymatic biosensors were prepared: four enzymatic sensors with only one layer of enzyme (proteinase K, trypsin, pronase or protease X) and three other enzymatic sensors with two layers (first layer: membrane containing proteinase K; second layer: one of the three other enzymes: trypsin, pronase or protease X). The biosensors were obtained through the deposition of enzymatic layers and the cross-linking process between enzymes and BSA in saturated glutaraldehyde vapour. The response of the various biosensors, described previously, were compared with the values of total organic carbon (TOC), and those of organic nitrogen (Norg), as determined by the laboratory accredits (CEMAGREF of Lyon) using the traditional method of analysis (NF EN 1484, infrared spectroscopy) and (NF EN 25663, mineralization/colorimetry assay) respectively for each water sample obtained from di erent sites in Lyon (France). The linear correlations obtained with the response of the seven biosensors showed the most important indices of correlations for the biosensor with two enzymatic layers: proteinase K + pronase (pkp). The optimum conditions for the preparation of the pkp biosensor increased the sensitivity and gave a limit of quantification of 0.583 g/L for TOC and 0.218 g/L for Norg in water samples. This sensor shows good reproducibility (2.28%), a capacity to be used at temperatures range 10– 30°C (depending on the season) and moreover a long lifetime (5 weeks).  相似文献   

13.
北京地区雨水中溶解态有机氯农药的特征及源解析   总被引:6,自引:1,他引:6       下载免费PDF全文
对2006年5月~2007年11月北京地区雨水中溶解态有机氯农药(OCPs)的组成特征进行分析并对其进行源解析.结果表明,DDTs、HCHs、七氯、氯丹、六氯苯、艾氏剂和狄氏剂7种OCPs被检出,其平均浓度分别为(6.66±4.99)ng/L,(10.30±12.39)ng/L,(2.62±1.87)ng/L,(6.54 ± 4.58)ng/L,(3.99±3.02)ng/L,(2.10±1.40)ng/L和(2.25±1.58)ng/L.OCPs的总浓度在研究期间内呈总体下降趋势,表明北京地区的OCPs污染得到了较好的控制.通过对特征化合物的解析发现,有疑似的林丹和三氯杀螨醇的输入源,各化合物之间显著的相关性说明OCPs的输入途径相似.雨水中的OCPs含量与温度不相关;与降雨量和相对湿度有弱的负相关性;其沉降通量与空气中污染物的浓度相关,与降水量相关性不显著.  相似文献   

14.
15.
Biosensors are analytical tools, which use the biological specificity in sensing the target molecule. In this paper, the author reviews the design and application of molecular biosensors for use in bioremediation. The promoter selected from a genetic operon has been described as an interactive biological component for the target molecule to generate the signal. Different types of reporter systems have been described and as well as their application in tracking of levels of pollutants, nitrogen, phosphorus, dissolved oxygen in different habitats and toxic compounds. The paper emphasizes that in order to extend the applications of this scientific area, specialized research is needed in the aspects pertaining to bringing the biological recognition element into close proximity to the target molecules so that it can be integrated with the signal analysis system.  相似文献   

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17.
生物滞留池是城市雨水低影响开发技术下的一种处理设施,由于其对污染物去除效果较好,运行条件不复杂,投资成本不高,在国内外得到广泛应用。基于国内外改良型生物滞留池研究动态的分析,提出生物滞留池经填料基质、厌氧环境、结构优化、有效蓄水深度、入渗率和水力流动方向等方面改良后,可在保持传统生物滞留池对悬浮颗粒物、重金属/类金属、病原体和油脂类等去除效果的同时,提升对氮、磷污染物的去除效果。总结了改良型生物滞留池处理城市雨水中污染物的基本原理与典型特征,归纳了改良型生物滞留池处理雨水的设计和应用范围,并对未来的研究与发展方向进行了展望,以期为海绵城市基础设施工程建设和老旧区城市改造提供参考。  相似文献   

18.
三峡水库库首地区大气降水化学特征   总被引:7,自引:0,他引:7       下载免费PDF全文
2009年6月~2010年7月对三峡水库库首地区大气降水的水化学特征进行了连续1年的研究.结果表明:三峡库首地区大气降水酸化严重,超过1/3的降水pH值低于4.5.SO42-和NO3-为降水中的最主要阴离子,雨量加权平均值分别为161.90,65.24μeq/L,二者分别占无机阴离子总量的66%、27%.Ca2+是最主要的阳离子,离子含量在8.89~932.90μeq/L之间,雨量加权平均浓度为108.34μeq/L,占无机阳离子总量的43%.季节变化分析表明,夏秋季节降水酸化严重,而冬春季节降水酸化不明显.不同季节相对酸度(FA)和中和因子(NF)分析表明,冬春季节的降水酸度主要受Ca2+离子的中和作用控制.主要离子来源分析表明,SO42-和NO3-主要来源于化石燃料燃烧,Na+、Cl-主要为海源输入的贡献,而Ca2+、Mg2+主要来源于陆壳颗粒物质.  相似文献   

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渤海海冰作为淡水资源:脱盐机理与可利用价值   总被引:40,自引:3,他引:40  
我国北部沿海地区缺水问题十分严重,但冬季在渤海及黄海北部形成较大范围的海冰。海冰因其成冰过程中盐分大量析出而盐度很低,可能成为解决这些地区缺水问题的重要淡水资源。论文根据实地观测和室内不同盐度海水的实验分析,阐述了渤海海冰盐度变化和海水成冰脱盐过程,并采用二次成冰脱盐和离心脱盐等方法,分析了海冰经进一步人工淡化的可能性,探讨了海冰作为淡水资源的可利用价值。  相似文献   

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