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961.
在乙二胺 (en)介质中 (p H1 1 .5~ 1 2 .3 ) ,Zn(en) 2 +3在单扫描示波极谱仪上于 -1 .42 V(vs.SCE)处产生一灵敏的络合物吸附波 ,锌含量在 0 .0 0 6~ 0 .3 5 μg/ml范围内 ,浓度与峰电流呈线性关系。检测限为 0 .0 0 3 μg/ml。加标回收率为92 %~ 1 0 3 % ,相对标准偏差小于 4.1 %。该方法准确、简便、选择性好 ,可用于 TSP中微量锌的测定。 相似文献
962.
垃圾焚烧厂是一类对环境有重大影响的建设项目 ,因此在建设焚烧厂之前 ,必须进行环境影响评价。文章在借鉴国外相关资料的基础上 ,结合国内的实际情况 ,探讨了垃圾焚烧厂环境影响评价的主要步骤和主要内容 相似文献
963.
建立了溴甲酚紫(BCP)-十八烷基二甲基苄基氯化铵(SDMBA-Cl)分光光度法测定水中阴离子表面活性剂的方法.实验表明,最适合的pH值为8左右,λmax=588nm,在1.0ml1.6×10-4mol/LSDMBA-Cl存在下,十二烷基苯磺酸钠(LAS)在0~5.0 mg/L内符合比耳定律,其摩尔吸光系数为4×104L·mol-1·cm-1.用此法测定河水和废水中的阴离子表面活性剂,相对标准偏差<3.8%,样品加标平均回收率为100.3%. 相似文献
964.
Sas-Nowosielska A Galimska-Stypa R Kucharski R Zielonka U Małkowski E Gray L 《Environmental monitoring and assessment》2008,137(1-3):101-109
Phytoremediation, an approach that uses plants to remediate contaminated soil through degradation, stabilization or accumulation,
may provide an efficient solution to some mercury contamination problems. This paper presents growth chamber experiments that
tested the ability of plant species to stabilize mercury in soil. Several indigenous herbaceous species and Salix viminalis were grown in soil collected from a mercury-contaminated site in southern Poland. The uptake and distribution of mercury
by these plants were investigated, and the growth and vitality of the plants through a part of one vegetative cycle were assessed.
The highest concentrations of mercury were found at the roots, but translocation to the aerial part also occurred. Most of
the plant species tested displayed good growth on mercury contaminated soil and sustained a rich microbial population in the
rhizosphere. The microbial populations of root-free soil and rhizosphere soil from all species were also examined. An inverse
correlation between the number of sulfur amino acid decomposing bacteria and root mercury content was observed. These results
indicate the potential for using some species of plants to treat mercury contaminated soil through stabilization rather than
extraction. The present investigation proposes a practical cost-effective temporary solution for phytostabilization of soil
with moderate mercury contamination as well as the basis for plant selection. 相似文献
965.
A geographic information system (GIS)-based approach with spatial analysis advantages was developed to optimize the total
emission control scheme on air pollution in Lanzhou, combined with Models-3 modeling system and a linear programming model.
GIS system is mainly used for establishing a multifactor assessment model to quantitatively divide environmental functional
zone, and also used for selecting control sites in linear programming model. The results show that most of the urban area
belongs to the second type of function, which is 122.8 km2 occupying about 76.5% and the third type of about 32.9 km2 occupying 20.5%. To reach the air quality up to the national standard in the entire control area, some large-emission factories
need to cut emissions from 19% to 27%. For small but low-emission height sources, the cut may be as high 40%. The improvement
of the ecological environment is urgently needed for controlling the background particle pollution in Lanzhou city. 相似文献
966.
Study on Management and Control of Nonpoint Source Pollution from Urban Surface Runoff 总被引:1,自引:0,他引:1
Chen Keliang Zhu Xiaodong Wang Xianghua Ma Yan 《中国人口.资源与环境(英文版)》2007,5(1):39-44
Urbanization is the dominant form of land-use change in terms of impacts on water quality, hydrology, physical properties of watersheds and their nonpoint source (NPS) pollution po-tential at present. Urbanization has changed the source, process and sink of urban NPS pollution, especially raised the pollution load of urban runoff NPS in receiving water. Urban runoff pollution is a hot spot of research on NPS. This paper analyzed type, source and harm of the NPS pollutants of urban runoff and its influence on the receiving water. Through estimating NPS pollution load of urban runoff and summarizing the law and characteristics of urban runoff NPS systemically, study on management and control of urban runoff NPS pollution was focused on the application of BMPs (best management practices). It is a fresh methodology that management and control on NPS pollution from urban surface runoff was analyzed by methods of landscape ecology, environmental economics and environmental management. The paper provided a scientific reference for mitigating urban water environment pressure and an effective method for management and control of NPS pollution from urban surface runoff. 相似文献
967.
Vacuum pyrolysis of waste tires with basic additives 总被引:3,自引:2,他引:1
Granules of waste tires were pyrolyzed under vacuum (3.5-10kPa) conditions, and the effects of temperature and basic additives (Na(2)CO(3), NaOH) on the properties of pyrolysis were thoroughly investigated. It was obvious that with or without basic additives, pyrolysis oil yield increased gradually to a maximum and subsequently decreased with a temperature increase from 450 degrees C to 600 degrees C, irrespective of the addition of basic additives to the reactor. The addition of NaOH facilitated pyrolysis dramatically, as a maximal pyrolysis oil yield of about 48wt% was achieved at 550 degrees C without the addition of basic additives, while a maximal pyrolysis oil yield of about 50wt% was achieved at 480 degrees C by adding 3wt% (w/w, powder/waste tire granules) of NaOH powder. The composition analysis of pyrolytic naphtha (i.b.p. (initial boiling point) approximately 205 degrees C) distilled from pyrolysis oil showed that more dl-limonene was obtained with basic additives and the maximal content of dl-limonene in pyrolysis oil was 12.39wt%, which is a valuable and widely-used fine chemical. However, no improvement in pyrolysis was observed with Na(2)CO(3) addition. Pyrolysis gas was mainly composed of H(2), CO, CH(4), CO(2), C(2)H(4) and C(2)H(6). Pyrolytic char had a surface area comparable to commercial carbon black, but its proportion of ash (above 11.5wt%) was much higher. 相似文献
968.
高校文书档案立卷改革的探索与应用 总被引:1,自引:0,他引:1
传统的立卷程序繁琐复杂,既浪费了人力、物力和财力,利用效果也不理想。随着社会的发展,传统的文书立卷方法已不适应档案管理现代化的需要,必须转变观念,把工作重点由“重藏轻用”转移到“简化管理、强化检索、重在利用”的新思路上来。新的规则取消了案卷,以件为单位进行整理归档,简单、易学、实用,有利于档案的保护、查找和利用。在新规则的实践过程中,档案工作者也需灵活掌握,改进工作方法。 相似文献
969.
Photocatalytic degradation of lignin was studied with the use of catalysts TiO(2) and Pt/TiO(2). The influence of several experimental parameters, i.e. pH, catalyst dosage and illumination on lignin degradation was investigated. The results showed that application of UV irradiation alone has almost no effect on the reduction of dissolved organic carbon (DOC) and American Dye Manufacture Institute value (ADMI). However, the addition of TiO(2) and Pt/TiO(2) reduced the original DOC (251 mg l(-1)) by more than 40% within 30 min of treatment and the reaction can be simulated with pseudo-first order kinetics. Rapid degradation of lignin was observed in acidic solution using either TiO(2) or Pt/TiO(2) as the catalyst compared to high pH cases. The content of Pt in the Pt/TiO(2) catalyst is 1%. In addition, too much catalyst addition has not increased the DOC and ADMI reduction proportionally. The investigation also indicated that the photocatalytic degradation rates could be enhanced 1-6 times faster after doping TiO(2) with Pt in different pH cases. A modified Nernst type model was adopted to simulate the decoloring process using TiO(2) and Pt/TiO(2) based on the profiles of oxidation reduction potential during the photocatalytic reaction. The developed equation can be used to predict the color removal efficiency of lignin wastewater by the photocatalytic process. 相似文献
970.
Kinetic degradation processes of butyl- and phenyltins in soils 总被引:3,自引:0,他引:3
The degradation of organotin compounds (OTC) in agricultural and forest soils is studied in sandy soil samples. Individual experiments involving the three butyl- and the three phenyltins were carried out during 90 d in controlled conditions (darkness, 28 degrees C, aerobic conditions, 13% moisture) and with spiking concentration representative of environmental levels (20-50 micrg(Sn) kg(-1)). After the validation of first-order degradation kinetic model, mechanisms involved throughout the study were considered. Degradation pathways are proposed for butyl- and phenyltins and discussed according to literature data. The degradation of mono- (MBT, MPhT), di-organotins (DBT, DPhT) and TBT is clearly identified as a single successive loss of an organic group whereas TPhT is directly degraded to MPhT. The half-life times were dependent on their substitution degree, ranging from 24 (TPhT) to 220 (MBT) d. The less substituted the OTC is, the more persistent it is. In the range 4.3-5.7, pH does not seem to influence OTC degradation under the present operating conditions. Finally this study shows the significant persistence in soil samples in our experimental conditions for most of studied organotins and highlights the potential impact on soil quality. 相似文献