纳米Y沸石对堆肥中氨气的吸附作用及其机理研究

利用自制的堆肥装置,研究了纳米Y沸石对生活垃圾堆肥中氨气吸附的规律,同时采用红外光谱技术分析了吸附氨气前后纳米Y沸石的变化,探讨了其对氨气吸附机理。试验结果表明:纳米Y沸石对氨气具有较好的吸附效果,最大吸附量可达到3.21×10-6mol/g,对氨气的最大去除率也可达到93.3%,并最终稳定在81%左右。纳米Y沸石对氨气的吸附作用机理属于物理吸附,可以通过一定方法解吸复原,解吸后的纳米Y沸石对氨气同样具有很好的吸附能力,去除率也能达到93%。     

A comparative study of Mn/CeO2, Mn/ZrO2 and Mn/Ce-ZrO2 for low temperature selective catalytic reduction of NO with NH3 in the presence of SO2 and H2O

Ce-ZrO2 is a widely used three-way catalyst support.Because of the large surface area and excellent redox quality,Ce-ZrO2 may have potential application in selective catalytic reduction(SCR) systems.In the present work,Ce-ZrO2 was introduced into a low-temperature SCR system and CeO2 and ZrO2 supports were also introduced to make a contrastive study.Mn/CeO2,Mn/ZrO2 and Mn/Ce-ZrO2 were prepared by impregnating these supports with Mn(NO3)2 solution,and have been characterized by N2-BET,XRD,TPR,TPD,XPS,FT-IR and TG.The activity and resistance to SO2 and H2O of the catalysts were investigated.Mn/Ce-ZrO2 and Mn/CeO2 were proved to have better low-temperature activities than Mn/ZrO2,and yielded 98.6% and 96.8% NO conversion at 180°C,respectively.This is mainly because Mn/Ce-ZrO2 and Mn/CeO2 had higher dispersion of manganese oxides,better redox properties and more weakly adsorbed oxygen species than Mn/ZrO2.In addition,Mn/Ce-ZrO2 showed a good resistance to SO2 and H2O and presented 87.1% NO conversion,even under SO2 and H2O treatment for 6 hours,and the activity of Mn/Ce-ZrO2 was almost restored to its original level after cutting off the injection of SO2 and H2O.This was due to the weak water absorption and weak sulfation process on the surface of the catalyst.     

FeSO_4对厌氧氨氧化微生物活性影响

研究FeSO4对厌氧氨氧化微生物活性的影响,考察不同总氮负荷下加入FeSO4的反应器与对照反应器出水NH+4-N、NO-2-N、NO-3-N出水浓度及反应器ΔTN,结果表明,当FeSO4浓度为0.1 mmol/L时,反应器NO-2-N出水浓度明显低于对照,反应器基质去除能力强于对照,而反应器NO-3-N出水浓度则高于对照,反应器厌氧氨氧化微生物活性及生物量高于对照。FeSO4可促进厌氧氨氧化微生物富集生长及活性提高,增强反应器基质去除能力及抗负荷冲击能力。     

城乡视听景观的变化及其对认知评价的影响

景观评价是国外环境质量评价和管理的重要组成部分。在快速城市化背景下,我国城乡的视觉景观和声景观质量正面临深刻变化。选取具有明显城市-乡村梯度的代表性景观,通过景观现场调查和室内评价测试,剖析了城市-乡村梯度下景观的视、听属性和人群的景观视、听及综合认知评价的变化,并探讨景观属性变化对认知评价的影响,以及视觉景观认知评价、声景观认知评价与景观视听综合评价之间的相互关系。结果表明:(1)沿城市-乡村梯度,视觉景观由人工景观逐渐过渡到自然景观,声景观由人工声为主逐渐过渡到以生物声和地质声为主,声级水平随之降低。(2)景观视听评价结果总体上随人工影响程度大小的下降而上升。(3)景观视听综合评价受视觉景观认知评价和声景观认知评价的共同影响,其中声景观认知评价对景观视听综合评价的贡献明显高于视觉景观认知评价。     

降尘/沉积物样品中多环芳烃[PAHs]和有机氯农药(OCPs)同时测定的固相萃取小柱净化条件

使用固相萃取小柱对降尘/沉积物中的22种有机氯农药和16种多环芳烃同时进行净化.结果表明,在相同淋洗条件下,使用弗罗里柱比硅胶柱净化效果更好.比较了小同溶剂体系、不不溶剂配比下两种萃取柱的净化效果,使用丙酮/正己烷(2%)或二氯甲烷/正己烷(20%)作为净化溶剂,较小的收集体积都可满足所有目标化合物的回收率要求;相比较...     

短时高温暴露对Q型烟粉虱发育和繁殖的影响

为探明卵期受短时高温暴露对Q型烟粉虱(Bemisia tabaci Q-biotype)存活、繁殖和后代适合度的影响,以适温(26℃)处理为对照,研究Q型烟粉虱卵在不同高温(37、39、41℃)条件下分别暴露1 h、2 h和4 h后转至适温饲养,其F0代的存活率、羽化率、雌成虫比例、寿命和产卵量及F1代的发育历期和雌成虫比例.结果表明:1)随着暴露温度升高和暴露时间延长,F0代Q型烟粉虱由卵发育至成虫的存活率和蛹羽化率均显著降低,41℃暴露2 h后的存活率和蛹羽化率最低,分别为49.1%和76.2%,显著低于未经高温暴露的对照(分别为83.4%和96.6%);2)卵期于41℃暴露1 h后其F0代雌成虫比例(61.0%)显著高于对照(52.0%),其他各处理与对照差异不显著;3)卵期高温暴露对F0代雌成虫寿命无显著影响,但单雌产卵量均显著低于对照(117.9粒),并随暴露温度升高呈降低趋势;4)F0代卵期在39℃暴露2 h、4 h和41℃暴露1~4 h后,F1代卵到成虫历期均较对照显著延长;5)与对照相比,F0代卵期分别在37℃暴露1~4 h、39℃暴露1~2 h或41℃暴露4 h,还可显著提高F1代雌成虫比例.可见,短时高温暴露可降低Q型烟粉虱的发育适合度,导致F0代存活率降低、产卵量下降和F1代发育历期延长,但一定程度上提高F1代雌成虫比例,从而对种群发展产生一定的代偿作用.表5参20     

基于层次分析法的库岸高速滑坡危险度评价

高速滑坡的判定是滑坡治理工作中的一项重要内容,但由于目前尚没有统一规范的滑速计算方法,因而给高速滑坡的预测带来了一定的困难。层次分析法是一种定性与定量相结合的多目标决策分析方法,针对库岸高速滑坡发生的各影响因子,采用层次分析法对鹅公带古滑坡体的高速滑坡体危险度进行了分析评价,为库岸高速滑坡的预测提供了一条新思路。     

氘灯对原子吸收法测定高盐废水中镉含量的影响

在石化行业中,由于采气废水多为高舍盐废水,如果按照地表水、地下水的测试方法对其重金属指标进行测试,其测试结果和真实值之间存在较大的偏差。本研究中采用火焰原子吸收法对影响吸收的背景进行氘灯扣除,得到了一种适合于高含盐废水体中镉含量测定的分析方法。通过实验验证,该方法相对误差在8．75％以内,检测限0．0042mg／L,回...     

企业不同层级员工安全文化培训探讨

安全文化在事故预防中具有不可替代的重要作用,而培训是企业安全文化改善技术手段的重要方面。本文在中国矿业大学（北京）安全管理课题组现阶段研究成果的基础上,研究来自山东、河南、山西、东北4个省的10个样本煤矿的四类层级员工——管理层、专业人员、班组长、一线员工的安全文化初始测量值、两次培训后的提高幅度值和32条核心理念的得分情况。得出初始安全文化测量值不同层次员工的得分从高至低依次为：管理层,专业人员,班组长,一线员工;第一次培训后提高幅度值从高到低为：班组长,专业人员,管理层,一线员工;第二次培训后提高幅度值从高到低为：班组长,一线员工,管理层,专业人员并分析了得分高低不同的原因。     

Effects of suspended sediment on the biodegradation and mineralization of phenanthrene in river water

High suspended sediment (SPS) concentration commonly exists in many Asian rivers. Furthermore, climate change can cause high floods and lead to the resuspension of sediments and soil erosion, resulting in high SPS concentration in many natural waters. This research studied the impact of the presence of SPS and organic C composition of SPS on the biodegradation and mineralization of phenanthrene (PHE). Three sediments, including original sediment (OS), 375 degrees C (S375), and 600 degrees C (S600) combusted sediment, were studied. A flask-based 14C-respirometer system was applied to study the mineralization of [14C]PHE by Agrobacterium sp. The mineralization rate of PHE in the absence of SPS was significantly lower than that with the presence of OS and S600 but higher than that with S375, suggesting that the effect of the presence of sediment on PHE mineralization depended on its organic C composition. The residual levels of PHE in the S375 and OS systems were about 1.5 times that of the S600 system after incubation for 2 d. After 26-d incubation, the mineralization rates of PHE were 34.64, 29.40, and 14.00% in the OS, S600, and S375 systems, respectively. The first-order rate constants of the OS and S600 systems were about three times that of the S375 system. The net influence of SPS on the biodegradation and mineralization rates of PHE was dependent on its effects on compound bioavailability and bacteria population. This study suggested that black C played a key role in reducing the mineralization rates of PHE in sediments-even without aging.