EDTA-（NH4）2FeSO4络合剂脱除烟气中的氮氧化物

络合脱硝法是近年来新型的脱除氮氧化物的方法之一,其中EDTA金属络合剂受到了广泛关注,而亚铁络合剂又具有很好的脱除氮氧化物的效果。考查了硫酸亚铁铵与EDTA形成的Fe（II）EDTA这种比较常见的EDTA金属络合剂对NO的吸收容量,并考查温度、络合剂浓度等对Fe（II）EDTA吸收NO的影响。研究结果表明：在相同的实验环境和实验条件下,对于影响Fe（II）EDTA吸收NO的因素最重要的是温度,其余依次为络合剂浓度、气体流速、氧含量、吸收液pH,最适宜吸收条件是反应温度50℃、络合剂浓度0．1mol／L、进气流速600mL／min、氧含量2％、吸收液pH=6。     

不同类型组合与滞留时间下串联型基质床净污效果

研究了不同基质床组合和不同滞留时间下对模拟生活污水的净化效果,并对2个影响因素进行二维方差分析。选取砾石、炉渣和沸石作为级配基质,构建由表流型基质床和潜流型基质床组成的4种三级串联基质床组合,设定污水滞留时间为1、3和5h。结果表明,不同基质床组合的净污效果存在显著性差异,其中由2个表流型基质床和1个潜流型基质床组成的系统对CODMn、NH4＋-N和PO34--P的去除率最高。不同滞留时间的净污效果也存在显著性差异,且污水在系统中滞留时间越长,去污效率越高。尽管不同基质床组合和滞留时间都对CODMn、NH4＋-N和PO34--P去除率有着显著性影响,但基质床组合与滞留时间的交互作用对去除率影响却不显著。     

我国不同区域水源水拉森指数比较分析

目前远距离调水已经成为解决区域水资源不足的一项重要措施。但在水源切换时,切换前后水源水的腐蚀性如果存在显著差异,可能会因腐蚀加剧而出现"黄水"或"红水"现象。因此,了解不同区域、不同类型水源的腐蚀性差异,对于科学合理地进行水资源调配具有重要意义。拉森指数(LR)是目前评价水质对铁质管网腐蚀程度的常用方法。本研究以14个城市的26个水源水为研究对象,对模拟常规工艺处理后的滤后水进行了水质分析,并计算出其拉森指数。结果表明,相对于湖库水和地下水,河流水的拉森指数偏高,有44%的河流水拉森指数大于1,具有较强的腐蚀倾向。按区域分华东和中南地区、按流域分黄河和珠江流域的水源水拉森指数平均值大于1,水源切换条件下应关注其腐蚀性情况。     

Water Transport in Polylactide and Polylactide/Montmorillonite Composites

Polylactide–montmorillonite composites were fabricated by melt-blending followed by compression molding, and water permeability of the composites was studied by both experiments and theoretical models. The water permeation in composites decreases with increasing concentration of montmorillonite. Specifically, at a concentration of 10 wt% of montmorillonite, the water permeation is 34 % less than in the neat polymer. Transmission electron microscopy (TEM) and wide-angle X-ray scattering (WAXS) results show that most of the montmorillonite particles are well-dispersed and randomly exfoliated in the polymer matrix. A fit of theoretical models to the permeation data estimates that montmorillonite platelets are mostly exfoliated in the polymer matrix and oriented randomly, which matches with results from WAXS and TEM.     

Remote sensing of aquatic vegetation distribution in Taihu Lake using an improved classification tree with modified thresholds

Classification trees (CT) have been used successfully in the past to classify aquatic vegetation from spectral indices (SI) obtained from remotely-sensed images. However, applying CT models developed for certain image dates to other time periods within the same year or among different years can reduce the classification accuracy. In this study, we developed CT models with modified thresholds using extreme SI values (CT(m)) to improve the stability of the models when applying them to different time periods. A total of 903 ground-truth samples were obtained in September of 2009 and 2010 and classified as emergent, floating-leaf, or submerged vegetation or other cover types. Classification trees were developed for 2009 (Model-09) and 2010 (Model-10) using field samples and a combination of two images from winter and summer. Overall accuracies of these models were 92.8% and 94.9%, respectively, which confirmed the ability of CT analysis to map aquatic vegetation in Taihu Lake. However, Model-10 had only 58.9-71.6% classification accuracy and 31.1-58.3% agreement (i.e., pixels classified the same in the two maps) for aquatic vegetation when it was applied to image pairs from both a different time period in 2010 and a similar time period in 2009. We developed a method to estimate the effects of extrinsic (EF) and intrinsic (IF) factors on model uncertainty using Modis images. Results indicated that 71.1% of the instability in classification between time periods was due to EF, which might include changes in atmospheric conditions, sun-view angle and water quality. The remainder was due to IF, such as phenological and growth status differences between time periods. The modified version of Model-10 (i.e. CT(m)) performed better than traditional CT with different image dates. When applied to 2009 images, the CT(m) version of Model-10 had very similar thresholds and performance as Model-09, with overall accuracies of 92.8% and 90.5% for Model-09 and the CT(m) version of Model-10, respectively. CT(m) decreased the variability related to EF and IF and thereby improved the applicability of the models to different time periods. In both practice and theory, our results suggested that CT(m) was more stable than traditional CT models and could be used to map aquatic vegetation in time periods other than the one for which the model was developed.     

生态—水力学法在山区小型引水电站最小下泄流量计算中的应用

以川西某山区小型引水式电站为例,选择水深和流速为生境参数,以华鲮为生态保护目标,计算河道的最小生态需水量和对应的电站最小下泄流量,并与Tennant法、代表年法的计算结果对比。结果表明,生态水深0.12m对应的最小生态流量和Ten nant法的结果差异度为8.63%,较合理;生境参数标准值对计算结果影响显著;在选择合适的参数和参数标准值的前提下,生态—水力学法适用于山区小型河流。     

环保修井作业配套技术研究

以吉林油田为例,对油水井修井过程中产生的污染源进行查找分析。针对井下作业工序多,工况复杂的特点,分析了修井作业施工过程的污染源,对污染源采取有效的清洁生产新工艺、新设备,在地面污染防治方面取得了较好的效果。该项技术在减少原油落地损失、降低劳动强度、改善工作环境以及节能等方面取得了较好的经济和社会效益。     

Effect of short-chain organic acids and pH on the behaviors of pyrene in soil-water system

The effects of five short-chain organic acids (SCOAs) on the behaviors of pyrene in soil-water system were investigated. The influences of the quantity and species of organic acids, pH, and soil dissolved organic matter were considered. The results showed the presence of SCOAs inhibited the adsorption and promoted the desorption of pyrene in the following order: citric acid>oxalic acid>tartaric acid>lactic acid>acetic acid. The decreased extents of pyrene adsorption performance enhanced with increasing SCOA concentrations, while the decreasing rate became less pronounced at high SCOA concentrations. In the presence of organic acids, the adsorption ability of pyrene decreased with increasing pH. However, there was a slight increase of pyrene adsorption with the addition of oxalic acid, tartaric acid and citric acid above pH 8. The capacity for pyrene retention differentiated significantly between the soils with and without dissolved organic matter. The presence of SCOAs was also favorable for the decrease of pyrene adsorption on soil without dissolved organic matter. The results of this study have important implications for the remediation of persistent organic pollutants in soil and groundwater.     

高职食品专业校企合作的问题及对策

校企合作教育是一种充分利用学校与企业等多种不同的教育环境和资源在培养人才方面的优势,培养适应企业需要的应用性专门人才的教育模式,对高职院校培养应用型人才具有重要的意义。但当前高职院校的校企合作中存在如政策法规不健全、合作机制不完善、企业的热情不高等问题,针对这些问题从政府政策、企业和学校三方面对其解决方法提出了建议。     

Characteristics and source apportionment of VOCs measured in Shanghai,China

Volatile organic compounds (VOCs) were measured from 2007 to 2010 at the center of Shanghai, China. Because VOCs are important precursors for ozone photochemical formation, detailed information of VOC sources needs to be investigated. The results show that the measured VOC concentrations in Shanghai are dominated by alkanes (43%) and aromatics (30%), following by halo-hydrocarbons (14%) and alkenes (6%). Based on the measured VOC concentrations, a receptor model (PMF; positive matrix factorization) coupled with the information related to VOC sources (the distribution of major industrial complex, meteorological conditions, etc.) is applied to identify the major VOC sources in Shanghai. The result shows that seven major VOC sources are identified by the PMF method, including (1) vehicle related source which contributes to 25% of the measured VOC concentrations, (2) solvent based industrial source to 17%, (3) fuel evaporation to 15%, (4) paint solvent usage to 15%, (5) steel related industrial production to 12%, (6) biomass/biofuel burning to 9%, and (7) coal burning to 7%. Furthermore, ozone formation potential related to VOC sources is calculated by the MIR (maximum incremental reactivity) technique. The most significant VOC source for ozone formation potential is solvent based industrial sources (27%), paint solvent usage (24%), vehicle related emissions (17%), steel related industrial productions (14%), fuel evaporations (9%), coal burning (6%), and biomass/biofuel burning (3%). The weekend effect on the VOC concentrations shows that VOC concentrations are generally higher in the weekdays than in the weekends at the sampling site, suggesting that traffic conditions and human activities have important impacts on the VOC emissions in Shanghai.