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991.
等离子体与光催化复合技术净化污水处理泵站臭气 总被引:1,自引:0,他引:1
用一种等离子体-光催化复合技术净化污水处理泵站臭气,研究表明该复合技术具有较显著的协同促进效应,通过改变等离子体发生单元与光催化单元的距离以及在两者之间放置去静电网,可消除等离子体单元产生的负电荷对光催化单元的不利影响,进一步提高其复合效应。同时还对这一复合技术产生协同效应的机理进行了分析,并在污水处理泵站实地考查了这种复合技术对臭气的净化效果。该技术对臭气中NH3的降解率可达46.1%,对H2S的降解率可达67.3%。 相似文献
992.
GOAL, SCOPE AND BACKGROUND: Air pollution has been of a major problem in the Pearl River Delta of south China, particularly during the last two decades. Emissions of air pollutants from industries have already led to damages in natural communities and environments in a wide range of the Delta area. Leaf parameters such as chlorophyll fluorescence, leaf area (LA), dry weight (DW) and leaf mass per area (LMA) had once been used as specific indexes of environmental stress. This study aims to determine in situ if the daily variation of chlorophyll fluorescence and other ecophysiological parameters in five seedlings of three woody species, Ilex rotunda, Ficus microcarpa and Machilus chinensis, could be used alone or in combination with other measurements for sensitivity indexes to make diagnoses under air pollution stress and, hence, to choose the correct tree species for urban afforestation in the Delta area. METHODS: Five seedlings of each species were transplanted in pot containers after their acclimation under shadowing conditions. Chlorophyll fluorescence measurements were made in situ by a portable fluorometer (OS-30, Opti-sciences, U.S.A). Ten random samples of leaves were picked from each species for LA measurements by area-meter (CI-203, CID, Inc., U.S.A). DW was determined after the leaf samples were dried to a constant weight at 65 degrees C. LMA was calculated as the ratio of DW/LA. Leaf N content was analyzed according to the Kjeldhal method, and the extraction of pigments was carried out according Lin et al. RESULTS AND DISCUSSION: The daily mean Fv/Fm (Fv is the variable fluorescence and Fm is the maximum fluorescence) analysis showed that Ilex rotunda and Ficus microcarpa were more highly resistant to pollution stress, followed by Machilus chinensis, implying that the efficiency of photosystem II in I. rotunda was less affected by air pollutants than the other two species. Little difference in daily change of Fv/Fm in I. rotunda between the polluted and the clean site was also observed. However, a relatively large variation of Fv/Fm appeared in the other two species, particularly in M. chinensis, suggesting that they were more sensitive to air pollutants than I. rotunda. The mean LA was reduced for all species growing at the polluted site. The mean LMA for all species exceeded the sclerophylly threshold given by Cowling and Campbell and increased for those under pollution stress, which could be explained as one of the acclimation strategies for plants to air pollution stress. Little difference in leaf chlorophyll content was observed in F. microcarpa and M. chinensis, while remarkable differences were found in I. rotunda growing at the polluted and the clean site. Content of leaf carotenoids was largely reduced in I. rotunda growing at the polluted site, but increased in F. microcarpa and M. chinensis, compared with plants growing at the clean site. Plants growing at the clean site had a lower leaf N content than those growing at the polluted site. In addition, species with a higher resistance to pollution stress showed less difference in leaf N content than those sensitive species. CONCLUSION: Based on Fv/Fm measurements of the three woody species, I. rotunda showed the highest resistance to air pollutants from ceramic industries, followed by F. microcarpa. M. chinensis was the most sensitive species to air pollution, had lowest capacities to cope with the air pollution stress, which was consistent with visual injury symptoms observed in the crown profiles of plants at the polluted site. Fv/Fm, LAM, LA, leaf pigments and N content could be used alone or in combination to diagnose the extent of the physiological injury. The ratio of Fv/Fm, however, was the best and most effective parameter. RECOMMENDATION AND OUTLOOK: Tree species which have higher air-pollutant resistance, as diagnosed by such ecophysiological parameters, should be considered first and planted widely for urban afforestation or forest regeneration in areas where the forest was seriously degraded or forest health was markedly effected by the same kind of air pollutants. 相似文献
993.
Soylak M Divrikli U Saracoglu S Elci L 《Environmental monitoring and assessment》2007,127(1-3):169-176
Cellulose nitrate membrane filter was used for the preconcentration-separation of Cu, Co, Cd, Pb and Cr ions. The analyte
ions were collected on the membrane filter by the aid of carmine. Then membrane filter was dissolved by using nitric acid.
The levels of the analytes in the final solutions were determined by flame atomic absorption spectrometry (FAAS). The analytical
parameters including pH, amounts of carmine, sample volumes etc. have been optimized. No influences have been observed from
the matrix ions. The detection limits for analytes were in the range of 0.08 μg/l-0.93 μg/l. The validation of the procedure
was checked by the analysis of standard reference sediment (GBW 07309). The present method has been successfully applied for
the FAAS determinations of analyte ions in real samples including black tea and magnesium salts. 相似文献
994.
冷原子荧光法测定生活垃圾堆肥产品中汞 总被引:2,自引:0,他引:2
通过试验研究,建立了用王水消解、冷原子荧光法测定生活垃圾堆肥产品中汞的方法.本方法的检出限为0.006 mg/kg (按称取0.5 g试样消解定容至50 ml计算),用于国内不同地域的堆肥样品测定,其相对标准偏差(RSD)在2.55%~10.7%之间,加标回收率介于91.0%~108.0%,可作为一种较理想的检验堆肥产品质量的方法. 相似文献
995.
Hoenicke R Davis JA Gunther A Mumley TE Abu-Saba K Taberski K 《Environmental monitoring and assessment》2003,81(1-3):15-25
The San Francisco Estuary Regional Monitoring Program (RMP) for Trace Substances is an innovative partnership among a regulatory agency, more than 70 regulated entities, and an independent scientific organization. The institutional arrangement behind the RMP has made the regulatory system increasingly responsive to emerging management needs, particularly with regard to the development of total maximum daily loads and ecosystem impairment assessment. Through multi-agency partnerships within and outside the RMP institutional structure, major information gaps for several pollutants of concern have been narrowed, resulting in a successful consensus-based regulatory approach to managing copper and nickel mass inputs into the Estuary. Short-term research efforts, based upon monitoring results, helped identify the most cost-effective control and remediation options for various bioaccumulative substances. Additionally, adaptive changes to the monitoring program documented the existence of widespread aquatic toxicity in the Estuary that is apparently due to pesticide runoff from agricultural and urban areas. One of the most important contributions of this collaborative monitoring program is the deliberate and systematic adjustment of management and research questions that serve to influence and add relevance to the overall research agenda related to San Francisco Estuary ecosystem assessment. 相似文献
996.
建立了一次性餐具中砷的氢化物发生-原子荧光测定方法,在选定的试验条件下,荧光强度与砷质量浓度在0μg/L-180μg/L范围内呈线性关系,相关系数0.999 3,溶液检测限0.5μg/L,回收率96%-101%。 相似文献
997.
Niedzielski P 《Environmental monitoring and assessment》2006,118(1-3):231-246
This paper presents the results of the determination of arsenic, antimony and selenium concentrations of inorganic speciation
in surface water samples from Gniezno city (western Poland) and its neighborhood. The concentration of elements were up to
1.85 ng/ml for arsenic, 1.61 ng/ml for antimony and 0.45 ng/ml for selenium (detection limits: 0.04 ng/ml for As and Sb and
0.03 ng/ml for Se). A variety of concentrations for the determined elements has been obtained in waters from Gniezno city’s
neighborhood and in water from down-town reservoirs which are under strong anthropogenic pressure. 相似文献
998.
The purpose of the present study was to evaluate the groundwater contamination due to the construction and operation of the
municipal landfill of Amari, Rethymno, Crete. The groundwater flow and leachate transport in the vadose and saturated zones
were studied and simulated, using three different models: the one-dimensional groundwater flow and contaminant transport model
for the vadose zone Pesticide Root Zone Model (PRZM-3), the Geographical Information System (GIS) Argus ONE and the three-dimensional
groundwater flow and contaminant transport model Princeton Transport Code (PTC). The simulation time was 30 and 20 years,
and the results obtained, according to the models and the existing hydrogeological conditions, were very encouraging and reassuring
about the groundwater quality of the broad region. 相似文献
999.
The Status of Pesticide Residues in the Drinking Water Sources in Meiliangwan Bay, Taihu Lake of China 总被引:10,自引:0,他引:10
The study was carried out to assess the levels of pesticide residues in the water of Meiliangwan Bay, Taihu Lake of China. The most commonly employed organochlorine pesticides (OCPs), organophosphorus pesticides (OPPs) and herbicide atrazine were analyzed. The water samples were collected seasonally from Meiliangwan Bay within a period of one year. The pesticides were analyzed by gas chromatography (GC) with μECD or NPD after solid-phase extraction (SPE), which was confirmed by GC with an ion trap mass spectrometry (MS). The mean concentrations were 1.98 ng/l for lindane, 0.378 ng/l for heptachlor epoxide, 0.367 ng/l for p,p′-DDE, 0.496 ng/l for p,p′-DDD, 1.06 ng/l for p,p′-DDT and 51.6 ng/l for dichlorvos, 39.0 ng/l for demeton, 346 ng/l for dimethoate, 4.12 ng/l for methyl parathion, 11.6 ng/l for malathion, 2.17 ng/l for parathion and 217 ng/l for atrazine. Generally, low concentrations of OCP were found, whereas the concentrations of the OPPs and atrazine in the water of Taihu Lake were relatively high. Heptachlor epoxide and lindane were the two most commonly encountered OCPs while dichlorvos, demeton and dimethoate were found to have much higher concentrations and occurrences than other OPPs. 相似文献
1000.
试验了用非全量消解—悬浮液直接进样火焰原子吸收光谱法测定煤灰中的铜和铅,结果表明:铜和铅的方法检出限(3σ)分别为0.038mg/L和0.23mg/L,测定吸光度与其浓度的线性范围均为0.5mg/L—5.0mg/L,样品加标回收率在87%—97%之间,相对标准差(n=4)小于7%。 相似文献