太湖竺山湾污染底泥环保疏浚深度的推算

根据颜色、气味、粒径、黏稠度等理化指标,将太湖竺山湾柱状底泥样品由上至下依次分为氧化层(A)、污染层(B)、污染过渡上层(C1)、污染过渡下层(C2)和健康层(D).通过对底泥中氨氮、总磷、总氮和烧失量垂直分布规律的分析,结合柱状底泥各分层氮、磷吸附/解吸实验,推算出竺山湾污染底泥环保疏浚层及其深度.结果表明,底泥中氨氮、总磷、总氮和烧失量含量随深度的增加呈下降趋势.A层和B层中污染物含量明显高于其他层;无机磷吸附/解吸平衡浓度随深度的增加而下降,在C1层与C2层间出现拐点;而氨氮的吸附/解吸平衡浓度变化趋势较复杂.结合上覆水中无机磷与氨氮浓度,推算出竺山湾底泥环保疏浚层次为C1层,疏浚平均深度为0.40~0.70m.     

黄河三角洲油田区土壤重金属的垂直分布规律及其影响因素

在黄河三角洲地区,由于胜利油田油气长期开采造成了采油区土壤环境质量的不断恶化.通过对胜利油田石油污染区土壤进行采样和分析,重点研究石油污染影响下10种重金属元素(Pb、V、Cr、Mn、Fe、Co、Ni、Cu、Zn和Cd)的含量、土壤粒径和总有机碳比重(TOC)分布规律.结果表明,19个土壤剖面的土壤颗粒d_(0.5)的范围为18—44μm,大部分属于细砂粒;但油田污染区土壤剖面重金属的垂直分布相较于对照组非污染区,二者存在明显差异:受石油烃及其降解产物的影响,油田区8种主要重金属(Pb、V、Mn、Fe、Co、Cu、Zn和Cd)在0—10 cm或10—20 cm层重金属含量最高,最大值分别为32.51、88.04、336.9、2.530×10~4、9.76、23.46、87.15、0.38 mg·kg~(-1);对照组受成土过程的影响,重金属在土壤深层(30—50 cm)出现两种不同的变化规律.通过聚类和相关性分析,油田区8种主要重金属(Pb、V、Mn、Fe、Co、Cu、Zn和Cd)浅层受泄漏石油影响为主,深层受土壤本底值影响为主,含量与土壤TOC(除去表层)的相关性较高;Cr、Ni则是受成土过程的影响.而非油区中8种重金属受大气沉降和成土过程的共同影响,含量与黏、粉粒之间普遍存在负相关关系,与TOC没有明显的相关性.分析结果表明,油区土壤中重金属的含量、迁移及其分布都受到了石油污染和油田开发的影响.该研究将对黄河三角洲湿地重金属-石油烃复合污染物污染的预防和治理提供一定的科学理论依据.     

液压汽车举升机的安全技术

汽车举升机是进行汽车维修和保养等作业的重要升降设备,我国早在上个世纪80年代就开始生产和使用。提高汽车举升机的安全性,保障人员生命和财产安全,配合特种设备监督管理,具有重要作用。汽车举升机安全技术检验尚处于探索阶段,目前唯一可参照的技术标准只有《汽车举升机技术条件》（JT／T155—2004）。由于全社会对其普遍缺乏认识,因此各地对其安全管理的程度也参差不一。     

暴雨是怎样形成的

正暴雨形成的过程是相当复杂的,一般从宏观物理条件来说,产生暴雨的主要物理条件是充足的源源不断的水汽、强盛而持久的气流上升运动和大气层结构的不稳定。大中小各种尺度的天气系统和下垫面特别是地形的有利组合可产生较大的暴雨。引起中国大范围暴雨的天气系统主要有锋、气旋、切变线、低涡、槽、台风、东风波和热带辐合带等。此外,在干旱与半干旱的局部地区热力性雷阵雨也可造成短历时、小面积的特大暴雨。     

基于多时相HJ影像的水稻洪涝灾情和产量监测

洪涝灾害是影响水稻生产的重要逆境因子。利用多时相HJ卫星影像数据评估了2012年辽宁洪涝灾害对水稻的影响。类似于土壤线,首先基于洪涝浑浊水体像元建立了水体线WL(NIR=0.693 1RED+0.022 7),并以此定义水体浑浊指数WTI和垂直植被指数PVI来分别监测洪涝水体的泥沙含量和水稻作物产量,对PVI与地面实测产量数据进行了相关分析,建立了灾后水稻产量与PVI的线性回归方程Yield=50 279PVI-2 804.1。研究结果表明,泥沙含量越高,水稻受灾越严重,产量越低。WTI可用于监测洪水泥沙含量,PVI则与水稻产量具有极显著的相关关系(R2=0.965),洪涝灾害对水稻的影响不仅可以从水稻收获前的遥感影像进行估测,更能够在洪涝灾害发生后及时进行估测,对洪涝灾后的水稻实际生产具有一定的指导意义。     

Diversity and vertical distributions of sediment bacteria in an urban river contaminated by nutrients and heavy metals

The aim of this study was to investigate the benthic bacterial communities in different depths of an urban river sediment accumulated with high concentrations of nutrients and metals. Vertical distributions of bacterial operational taxonomic units （OTUs） and chemical para- meters （nutrients： NH4＋, NO3, dissolved organic carbon, and acid volatile sulfur; metals： Fe, Zn, and Cu） were characterized in 30 cm sediment cores. The bacterial OTUs were measured using the terminal restriction fragment length polymorphism analysis. Biodiversity indexes and multivariate statistical analyses were used to characterize the spatial distributions of microbial diversity in response to the environmental parameters. Results showed that concentrations of the nutrients and metals in this river sediment were higher than those in similar studies. Furthermore, high microbial richness and diversity appeared in the sediment. The diversity did not vary obviously in the whole sediment profile. The change of the diversity indexes and the affiliations of the OTUs showed that the top layer had different bacterial community structure from deeper layers due to the hydrological disturbance and redox change in the surface sediment. The dominant bacterial OTUs ubiquitously existed in the deeper sediment layers （5-27 cm） corresponding to the distributions of the nutrients and metals. With much higher diversity than the dominant OTUs, the minor bacterial assemblages varied with depths, which might be affected by the sedimentation process and the environmental competition pressure.     

Decontamination efficiency and root structure change in the plant-intercropping model in vertical-flow constructed wetlands

Subtropical climatic conditions can contribute to the death of the aerial parts of constructed wetland plants in winter. This presents a barrier to the widespread application of constructed wetland and is an issue that urgently needs to be solved. Three contrasting experi- ments, the plant-intercropping model （A）, the warm- seasonal plant model （B）, and the non-plant model （C）, were studied in terms of their efficiency in removing pollutants, and the change in root structure of plants in the plant-intercropping model within the vertical-flow con- structed wetlands. The results indicate that model A was able to solve the aforementioned problem. Overall, average removal rates of three pollutants （CODcr, total nitrogen （TN） and total phosphorous （TP）） using model A were significantly higher than those obtained using models B and C （P 〈 0.01）. Moreover, no significant differences in removal rates of the three pollutants were detected between A and B during the higher temperature part of the year （P〉 0.05）. Conversely, removal rates of the three pollutants were found to be significantly higher using model A than those observed using model B during the lower temperature part of the year （P 〈 0.01）. Furthermore, the morphologies and internal structures of plant roots further demonstrate that numerous white roots, whose distribution in soil was generally shallow, extend further under model A. The roots of these aquatic plants have an aerenchyma structure composed of parenchyma cells, therefore, roots of the cold-seasonal plants with major growth advantages used in A were capable of creating a more favorable vertical-flow constructed wetlands media- microenvironment. In conclusion, the plant-intercropping model （A） is more suitable for use in the cold environment experienced by constructed wetland during winter.     

外加碳源水淹条件下高硫土壤中铜的迁移转化

采用高硫低有机质酸性重金属污染土壤,通过研究外加碳源水淹条件下各层土壤中酸可挥发性硫化物(AVS)的产生以及各剖面层中Cu的总量分布、Cu在孔隙水中的浓度及存在形态的变化情况,探讨了水淹土壤中的AVS对Cu迁移转化的影响.结果表明,外加碳源水淹条件下,硫酸根被还原,产生的大量AVS可促使水相中游离活性Cu向惰性较高的硫化物结合态和残渣态转化而被固定;不同深度土壤中AVS产生情况不同,其含量由深层向浅层递增,并在顶层大量聚集,由此导致孔隙水中的Cu²⁺浓度由土壤深层向浅层递减,这种垂直浓度梯度差,趋动活性态Cu由深层向浅层的垂直迁移,在AVS大量富集的表层中形成丰富的铜硫化物沉淀,使土壤表层中惰性态铜及总量累积增加,底层活性铜及总量下降,从而使铜的生态风险和生物风险降低.     

垂直潜流人工湿地堵塞及其运行效果影响研究

在净化猪场沼液中开展了垂直潜流人工湿地堵塞过程及其运行效能变化的研究.结果表明,人工湿地堵塞的主要成因是由于填料层中不可滤过性物质的积累所致.不可滤过性物质是由有机物和无机物组成,且大部分不可滤过性物质的粒径均超过5.00 μm.填料层的孔隙率和水力传导系数均随系统运行时间的延长而减小,而填料层中被截留物质的含量则随系统运行时间的延长而增大,其空间变化特征均受到了系统中水力流态的影响;当系统HLR为0.02m3/(m2·d)时,VSSF在运行1380d后对猪场沼液的净化开始恶化,系统对COD、TSS、TN、NH4+-N和TP的去除率分别降至37.31%、57.82%、20.80%、32.13%和51.18%.     

2013年秋末黄渤海海水中胞外酶活性水平和垂直变化

于2013年11月6~23日对黄渤海进行了现场调查研究,对42个大面站以及A7、E7两个垂直站位进行了采样及环境参数的测定,研究了该海域海水中的9种胞外酶活性的水平及垂直变化.结果表明:秋末黄渤海表层海水中,9种胞外酶的平均活性由高到低排列为碱性磷酸酶[77.31nmol/(L·h)]>脂肪酶[23.59nmol/(L·h)]>β-D-葡萄糖苷酶[3.87nmol/(L·h)]>木糖苷酶[2.63nmol/(L·h)]>α-D-葡萄糖苷酶[1.58nmol/(L·h)]≈纤维素酶[1.47nmol/(L·h)]≈几丁质酶[1.29nmol/(L·h)]>肽酶[1.09nmol/(L·h)]>β-D-半乳糖苷酶[0.74nmol/(L·h)];表层海水9种胞外酶的活性大都呈现出黄海大于渤海,即南高北低的变化规律;表层海水中的β-D-葡萄糖苷酶活性和纤维素酶活性与温度呈现弱的正相关(P0.05);A7和E7两个站位的胞外酶活性的垂直分布显示不同胞外酶的活性在不同水深有明显的差异,基本表现为表层、10m和30m的活性高于50m、75m和底层的活性.