化学需氧量和高锰酸盐指数相关性探讨研究

选取淮河流域临沂市4个出境监测断面2014年1～11月,每月上下旬各一次化学需氧量和高锰酸盐指数浓度的分析,利用每个监测断面21对化学需氧量和高锰酸盐指数浓度的监测结果,分析了临沂境内4个出境断面两个水质参数的相关关系,给出各断面二者的一元线性回归方程及相关系数并 F检验,得出不同断面二者的相关性及因水质不同相关性的差异。通过分析同一样品的二者的监测结果的相关性,相互佐证,从多角度进行质量控制和质量保证。提出二者相关性分析结果在实际使用的建议,以期引起从事水环境监测分析、监测评价和监测管理等相关人员重视。     

Antibiotic exposure and potential risk of depression in the Chinese elderly: a biomonitoring-based population study

Environmental Science and Pollution Research - To examine the associations between urinary antibiotics from various sources and depression in the elderly using the biomonitoring method. In the...     

污泥-秸秆活性炭制备过程热化学分析

以市政污泥和玉米秸秆为原料,氯化锌为活化剂制备活性炭,采用BET、TG/DTG和DTA等方法对其性能进行分析。结果表明,秸秆添加量(质量比)为30%时活性炭吸附效果最好,热解分为水分析出、挥发分析出和终态稳定3个阶段,热解过程为放热反应,热解1 kg干基原料(秸秆质量比为30%)得到热解气、热解液和残炭的能量分别为1 880.49kJ、8 354.22 kJ、2 301.84 kJ,剩余能量为11 502.53 kJ。     

Soil effects of six different two-species litter mixtures that include Ulmus pumila

The tree species that contribute to decomposed leaf litter can have important effects on soil properties and thus nutrient cycling and interactions between tree species. We examined ground leaf litter and soil mixtures consisting of leaves from Ulmus pumila (Up) combined individually with leaves from one of six other species: Betula platyphylla (Bp), Quercus liaotungensis (Ql), Salix matsudana (Sm), Hippophae rhamnoides (Hr), Caragana microphylla (Cm), and Amorpha fruticosa (Af). The soil–litter mixtures were incubated for 120 days to analyse the effects of their decomposition on soil properties and to determine the interactions between the different types of litter within each mixture. The decomposed litter mixtures were composed of Up combined with Sm- or Hr-improved soil fertility relative to the pure Up mixture, but the decomposed litter mixtures were composed of Up combined with Cm-, Af-, or Ql-diminished soil properties. Three leaf mixture treatments, namely Up?×?Bp, Up?×?Sm, and Up?×?Hr, exhibited synergistic effects on soil properties (i.e. soil properties exceeding the predicted values); however, three other treatments, namely Up?×?Ql, Up?×?Cm, and Up?×?Af, exhibited antagonistic effects (i.e. properties below the predicted values). Therefore, litter from Bp, Sm, or Hr should be mixed with Up to improve soil fertility and production in plantations.     

填料在净化污水过程中渗透性能变化趋势的研究

选取腐殖垃圾和砂以及两者质量比分别为4:1、3:2、2:3的混合物共5种填料,在1.0 m/d的水力负荷下,进行人工快速渗滤系统净化生活污水的试验,研究填料在进水过程中渗透性能的变化趋势.结果表明,腐殖垃圾的初始饱和水力渗透系数(K)最大,为3.32×10-2cm/s,而砂的初始K只有5.14×10-3cm/s,腐殖垃圾含量越大的混合物其仞始K也越大.在净化污水的过程中,5种填料的K逐渐减小,腐殖垃圾含量越大的混合物其K降幅也越大.随着进水时间的延长,各个填料柱填料层50～250 mm处的水头损失占总水头损失(填料层50～450mm处)的比例均逐渐增加,最终各个填料柱均发生堵塞,堵塞均发生在填料层50mm以上范围内.     

Bayesian estimation of age-specific bird nest survival rates with categorical covariates

The populations of many North American landbirds are showing signs of declining. Gathering information on breeding productivity allows critical assessment of population performance and helps identify good habitat-management practices. He (Biometrics (2003) 59 962–973) proposed a Bayesian model to estimate the age-specific nest survival rates. The model allows irregular visiting schedule under the assumption that the observed nests have homogeneous nest survival. Because nest survival studies are often conducted in different sites and time periods, it is not realistic to assume homogeneous nest survival. In this paper, we extend He’s model by incorporating these factors as categorical covariates. The simulation results show that the Bayesian hierarchical model can produce satisfactory estimates on nest survival and capture different factor effects. Finally the model is applied to a Missouri red-winged blackbird data set.     

Biomass reduction and arsenic transformation during composting of arsenic-rich hyperaccumulator <Emphasis Type="Italic">Pteris vittata</Emphasis> L.

Background, aim, and scope  

Composting is being proposed as a pretreatment step before disposal of metal-rich biomass after phytoextraction process. This study determined the biomass reduction and arsenic transformation during composting As-rich biomass of hyperaccumulator Chinese brake fern (Pteris vittata L.).     

邻氨基苯甲醚的清洁生产工艺

采用清洁生产的理论与思维模式,对合成邻氨基苯甲醚的传统工艺进行了改造,开发出以质量分数5％的Pd／C为催化剂、加氢制备邻氨基苯甲醚的清洁生产工艺。最佳生产工艺条件为：100g邻硝基苯甲醚中加入0．9g催化剂、溶剂与邻硝基苯甲醚的质量比0．75、反应压力0．7MPa、反应温度80℃。与传统的硫化钠还原工艺相比,该工艺使反应时间由6h缩短到1．75h,产品收率由90．5％提高到93．8％,解决了原工艺产生大量含硫废水的问题,每吨产品的生产成本可降低1650元。     

农村环境保护与"三农"问题

本文通过分析环境污染与生态破坏制约农业持续发展．威胁农民生命财产安全、扰乱农村稳定．阐明了农村环境问题是“三农“问题的重要内涵：通过剖析加剧“三农”矛盾的农村环境问题的主要根源．针对性地提出了促进农业持续发展与农村和谐、保障农民生命财产安全的农村环境保护措施。     

白泥对填埋场垃圾降解的影响实验研究

在4个相同的密封聚乙烯塑料罐中,分别装填相同组分和重量的青岛市居民区的生活垃圾,并且在4个罐中按不同比例添加白泥,与垃圾混合均匀。实验模拟填埋场的环境条件。定期监测4个罐渗滤液的水质变化,分析比较白泥的添加及添加量的多少对渗滤液的衰减的影响。实验结果表明,白泥的添加能够向反应系统提供一定数量的碱度,可以防止反应系统因出现酸过度累积而受到抑制,在一定程度上加快了垃圾的降解进程。这不仅对于减轻渗滤液处理设施的负荷、加速填埋场的稳定化起着积极作用,而且可以为白泥的资源化利用提供一个可行的途径。