水合肼生产盐渣中氮化合物的去除

将水合肼生产盐渣分离碳酸钠后,通过吹脱、氧化等工艺降低饱和盐溶液的氮含量(以氨质量浓度计),以达到电解法制备氢氧化钠工艺对原料氯化钠的使用要求。中试试验结果表明:氧化反应最佳工艺条件为以次氯酸钠为氧化剂,次氯酸钠溶液中氢氧化钠质量浓度9.2g/L,次氯酸钠与初始氨的质量比为13,溶液pH 7～8,反应温度30～35℃;在此条件下氧化处理饱和盐溶液,处理后氨质量浓度由350.0 mg/L降至2.1 mg/L。将处理后的饱和盐溶液用于电解法制备氢氧化钠的生产过程,不仅可创造一定的经济效益,而且还解决了水合肼生产中的环境污染问题。     

工业污染治理投资完成状况分析研究——以我国沿海省市为例

运用多元统计中的主成分分析法和系统聚类法对我国东部地区工业污染的治理投资完成情况进行了分析。根据主成分分析结果,对选取的11个省市进行分类,并在此基础上提出加强各区域环境污染治理的几点建议。     

Rapid detection of toxic metals in non-crushed oyster shells by portable X-ray fluorescence spectrometry

The aim of this study was the multi-elemental detection of toxic metals such as lead (Pb) in non-crushed oyster shells by using a portable X-ray fluorescence (XRF) spectrometer. A rapid, simultaneous multi-element analytical methodology for non-crushed oyster shells has been developed using a portable XRF which provides a quick, quantitative, non-destructive, and cost-effective mean for assessment of oyster shell contamination from Pb. Pb contamination in oyster shells was further confirmed by scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). The results indicated that Pb is distributed in-homogeneously in contaminated shells. Oyster shells have a lamellar structure that could contribute to the high accumulation of Pb on oyster shells.     

A competitive indirect enzyme-linked immunoassay for lead ion measurement using mAbs against the lead-DTPA complex

Immunoassays for quantitative measurement of environmental heavy metals offer several advantages over other traditional methods. To develop an immunoassay for lead, Balb/c mice were immunized with a lead-chelate-protein conjugate to allow maximum exposure of the metal to the immune system. Three stable hybridoma cell lines were obtained through spleen cells fusion with Sp2/0 cells. One cell line, 2A11D11, produced mAbs with preferential selectivity and sensitivity for Pb-DTPA than DTPA, exhibiting an affinity constant of 3.34 ± 0.24 × 10⁹ M⁻¹. Cross reactivity (CR) with other metals were below 1%, except for Fe(III) with a CR less than 5%. This quantitative indirect ELISA for the lead ion was used to detect environmental lead content in local water sources; importantly, the results from the immunoassay were in excellent agreement with those from ICP-MS. Development of immunoassays for metal ions may thus facilitate the detection and regulation of environmental pollution.     

Evaluation of the National Land Cover Database for Hydrologic Applications in Urban and Suburban Baltimore,Maryland1

Smith, Monica Lipscomb, Weiqi Zhou, Mary Cadenasso, Morgan Grove, and Lawrence E. Band, 2010. Evaluation of the National Land Cover Database for Hydrologic Applications in Urban and Suburban Baltimore, Maryland. Journal of the American Water Resources Association (JAWRA) 46(2):429-442. DOI: 10.1111/j.1752-1688.2009.00412.x Abstract: We compared the National Land Cover Database (NLCD) 2001 land cover, impervious, and canopy data products to land cover data derived from 0.6-m resolution three-band digital imagery and ancillary data. We conducted this comparison at the 1 km², 9 km², and gauged watershed scales within the Baltimore Ecosystem Study to determine the usefulness and limitations of the NLCD in heterogeneous urban to exurban environments for the determination of land-cover information for hydrological applications. Although the NLCD canopy and impervious data are significantly correlated with the high-resolution land-cover dataset, both layers exhibit bias at <10 and >70% cover. The ratio of total impervious area and connected impervious area differs along the range of percent imperviousness – at low percent imperviousness, the NLCD is a better predictor of pavement alone, whereas at higher percent imperviousness, buildings and pavement together more resemble NLCD impervious estimates. The land-cover composition and range for each NLCD urban land category (developed open space, low-intensity, medium-intensity, and high-intensity developed) is more variable in areas of low-intensity development. Fine-vegetation land-cover/lawn area is incorporated in a large number of land use categories with no ability to extract this land cover from the NLCD. These findings reveal that the NLCD may yield important biases in urban, suburban, and exurban hydrologic analyses where land cover is characterized by fine-scale spatial heterogeneity.     

Dynamic Tracking and Comprehensive Evaluation on the Natural Resources Security Elements and System in China

System theory,pressure-state-response and drivingpressure-state-impact-response model have been applied to establishing China's dynamic tracking evaluation system of natural resources security in this article.Based on analytic hierarchy process and Delphi methods,the natural resources security situation has been evaluated systematically from 1991 to 2007.The result showed that the overall level of China's natural resources security presented a downtrend from 1991 to 2007.The basic reasons are the pressure indicators such as population,GDP,natural resources trade increased gradually,resulting in tension and fragility of natural resources security.     

基于GIS的茂县水资源开发利用信息管理评价系统设计

为了实现对茂县水资源的高效利用,将水资源开发利用评价的知识与地理信息系统结合在一起,设计出一个基于GIS的水资源开发利用评价系统,从而对茂县的水资源合理利用和加大开发提供一个有力支持,以满足对茂县经济社会发展的要求。本文对该系统的需求分析、系统结构、数据、系统各功能、系统实现进行了说明。     

好氧颗粒污泥同时脱氮除磷技术研究

采用序批式活性污泥法(SBR)处理新疆油田公司准东石油基地污水,作为生物膜的一种特殊形式,介绍了该工艺的优点,在适宜的运行条件下进行实验。讨论了好氧颗粒污泥脱氮以及除磷的过程,分析了该工艺对氮、磷的去除率及好氧颗粒污泥在好氧、缺氧条件下的吸磷情况,当进水氨氮、磷和乙酸碳浓度分别为38.2 mg/L、27.7 mg/L和134.6 mg/L,MLSS和MLVSS分别为7.0 mg/L、6.4 mg/L时,氨氮、总无机氮、磷、乙酸碳的平均去除率分别达到98.8%、90.2%、98.9%、97.2%.     

提高油田伴生气回收率的研究与应用

文章阐述了陆梁油田在开发过程中采用油气混输技术、天然气发电机橇技术、锅炉烧湿气等技术,将伴生气回收率提高至92.10%;油气混输技术能够实现边缘区块油气全密闭输送;集中处理站锅炉燃烧湿气技术可增加处理站天然气外输气量,降低运行成本;小型活动天然气发电机橇的应用,可以充分利用富裕天然气降低生产成本,同时减少富裕天然气火炬放空燃烧量,收到了良好的经济效益和环境效益。     

Perennial filter strips reduce nitrate levels in soil and shallow groundwater after grassland-to-cropland conversion

Many croplands planted to perennial grasses under the Conservation Reserve Program are being returned to crop production, and with potential consequences for water quality. The objective of this study was to quantify the impact of grassland-to-cropland conversion on nitrate-nitrogen (NO3-N) concentrations in soil and shallow groundwater and to assess the potential for perennial filter strips (PFS) to mitigate increases in NO3-N levels. The study, conducted at the Neal Smith National Wildlife Refuge (NSNWR) in central Iowa, consisted of a balanced incomplete block design with 12 watersheds and four watershed-scale treatments having different proportions and topographic positions of PFS planted in native prairie grasses: 100% rowcrop, 10% PFS (toeslope position), 10% PFS (distributed on toe and as contour strips), and 20 PFS (distributed on toe and as contour strips). All treatments were established in fall 2006 on watersheds that were under bromegrass (Bromus L.) cover for at least 10 yr. Nonperennial areas were maintained under a no-till 2-yr corn (Zea mays L.)--soybean [Glycine max. (L.) Merr.] rotation since spring 2007. Suction lysimeter and shallow groundwater wells located at upslope and toeslope positions were sampled monthly during the growing season to determine NO3-N concentration from 2005 to 2008. The results indicated significant increases in NO3-N concentration in soil and groundwater following grassland-to-cropland conversion. Nitrate-nitrogen levels in the vadose zone and groundwater under PFS were lower compared with 100% cropland, with the most significant differences occurring at the toeslope position. During the years following conversion, PFS mitigated increases in subsurface nitrate, but long-term monitoring is needed to observe and understand the full response to land-use conversion.