对一起汽车槽车装车过程中发生闪燃着火事件的分析

利用故障树分析(FTA)对汽车槽车装车过程中引起的闪燃着火事件进行了分析,针对中转油站存在的安全隐患提出整改措施.     

Simulation and control strategy for the variational influent of WWTP

With the development of activated sludge model, the simulation software for the design and operation of wastewater treatment plant （WWTP） was produced and has been widely used. The dynamic change of the quality and flow of influent are major factors causing the unstable operation of wastewater treatment process. As a basic model, ASMI model was used for the simulation of activated sludge process, and double exponential model was selected for the simulation of secondary sedimentation tank. The influences of influent change to the aeration tank and secondary sedimentation tank were investigated, and the relationship among influent change, the quality of effluent and the level of sludge blanket in secondary sedimentation tank was established. On the basis of the simulation results, the operation of the WWTP could be adjusted under the dynamic change of the influent. Furthermore, the controlling strategy combined the feed-forward on the influent flow and the feedback on the level of sludge blanket in the secondary sedimentation tank was studied.     

半透膜覆盖好氧堆肥技术应用现状综述

膜覆盖好氧堆肥技术是近年来有机质好氧处理方式的研究热点,该技术主要由膜覆盖系统、微压送风系统和控制系统组成.膜盖层是由两层高品质抗紫外线布层和一层聚四氟乙烯半透膜组成的3层材料,具有耐水透气的优点,既能阻隔外界环境使堆体不受雨雪天气影响,又能减少臭气的挥发,使堆体达到封闭发酵的环境条件.本文介绍了膜覆盖好氧堆肥技术的特点及优缺点,阐述了国内外膜覆盖好氧堆肥技术的研究进展和应用现状,分析了我国在膜覆盖好氧堆肥技术领域研究的不足之处,并指出未来应加深对堆肥全过程的工艺过程控制研究,拓展膜覆盖的应用范围,用于畜禽粪便、餐厨垃圾等其它有机垃圾处理领域.     

流动海水环境中人工破损有机涂层的劣化过程研究

目的研究流动海水环境中人工破损有机涂层的劣化过程。方法使用电化学阻抗谱(EIS)技术对比研究流动海水与静止海水环境中破损涂层的劣化行为,跟踪观察涂层宏观形貌演变。结果根据EIS响应特征,发现流动海水中的人工破损有机涂层劣化更快,且在浸泡后期流动海水中破损涂层没有形成扩散阻抗。根据涂层宏观形貌发展,发现静止海水中涂层仅围绕破损处出现了面积较小的锈点和鼓泡,而流动海水中涂层因劣化而产生的锈点和鼓泡面积更大且大量分布在整个涂层表面。结论当人工破损有机涂层在流动海水和静止海水环境的浸泡过程中,涂层劣化首先从人工破损处开始。破损处成为局部腐蚀反应主要的阳极区,破损处周围的区域和涂层内在缺陷处成为扩展腐蚀反应的阴极区。流动海水中涂层的腐蚀产物累积与脱落更加频繁,导致涂层劣化速度加快和基体金属腐蚀加剧。     

膜覆盖条垛堆肥技术与应用案例

膜覆盖技术是一种改良的静态条垛堆肥技术,主工艺过程与传统高温好氧发酵工艺过程类似。介绍了膜覆盖堆肥系统的核心技术——功能性覆盖膜、曝气系统、卷膜设备;通过对膜覆盖系统的优势和不足的分析,得到该技术的适用范围;介绍了两个应用案例。     

几种常见非国标法颗粒物切割器性能评价及问题分析

通过搭建基于静态箱法的切割器捕集效率评价系统,分别评价了几种常见国产非国标法颗粒物切割器的性能.结果表明,2~3 L·min^-1的小流量国产切割器的D_a50在2.5 μm附近,但曲线形状与标准形状差异较大,几何标准偏差不符合要求;可调流量国产切割器符合国家标准对PM_2.5切割器的性能要求,但不符合对PM₁₀切割器的性能要求;带切换阀切割器的切换阀如果未能完全切换到预定位置,会影响切割器的性能指标.通过与同类型的进口切割器对比,揭示了国产非国标法颗粒物切割器目前存在的问题较多,并对其提出了改进建议,如提高切割器的加工精度、优化切换阀控制准确度等.     

Lead redistribution in a mine soil treated with three manures and incubated at two different temperatures

The study of heavy metals’ redistribution between different fractions allows to know their bioavailability and mobility in soils. Soil samples were collected from a lead mine in Hamadan provinces, NW Iran. In a factorial experiment soil was treated with cow, sheep and poultry manures (20?g?kg^?1 soil) separately and incubated near field capacity at 10°C and 37°C. An untreated soil (as control) was also incubated at the same temperatures. After 0 and 120 days, a sequential extraction scheme was used to fractionate Pb of incubated samples into soluble-exchangeable (Sol-Exch), organic matter associated (AOM), carbonates associated (ACar), and residual (Res) forms. Soil Pb in Sol-Exch and AOM fractions were increased by manure application significantly. The AOM and ACar forms of Pb were higher in soils treated with the manures and incubated in lower temperature. In contrast, the Sol-Exch and Res chemical forms of Pb were higher in the soils incubated at 37°C. These results may be related to the higher calcium carbonate dissolution and organic matter decomposition because of better biological activity in the soils incubated in higher temperature. The increase of the Res fraction (stable form) in this condition may resulted in lower toxicity and mobility in soil environment.     

兰州市南北两山不同生境红砂种群数量动态研究

对兰州市南北两山不同生境天然分布的红砂种群进行数量动态研究,通过径级结构回归年龄结构,编制静态生命表,绘制生存函数曲线,计算动态指数及谱分析,结果表明:不同生境红砂种群均表现为幼龄个体多,中老龄个体少,种群在Ⅲ龄级时死亡率最高,随着年龄增加,死亡率有所降低,Ⅶ、Ⅷ龄级由于生理衰老死亡率上升,种群存活曲线均接近于Deevey-Ⅲ型,年龄结构均接近增长型,增长潜力阴坡山下(5.90%)>阳坡山下(5.62%)>阴坡山上(4.77%)>阳坡山上(3.79%),并存在明显的周期性,红砂种群的数量动态变化整体上受其生命周期中生物学特性的控制;由于坡向及海拔差异带来的环境异质性,阴坡山下红砂种群整体生长最佳,阴坡山上和阳坡山下次之,而阳坡山上的红砂种群危险系数最大,受环境和种内压力共同作用显著,应适当抚育,从而促进种群持续发育。     

水稻强化栽培体系的CH4排放特征

紫色土稻作区是川中丘陵区的主要生态系统类型,而水稻强化栽培技术因其巨大的增产潜力而日益受到关注和推广,为了解这一生态区域稻田强化栽培体系的碳过程,同时为中国紫色土地区稻田CH4排放总量提供数据依据,利用静态箱/气相色谱法原位观测水稻(Oryza Sativa Linnaeu)强化栽培体系CH4排放通量特征。结果表明:齐穗期和成熟期稻田CH4排放存在明显的日变化,曲线均为单峰单谷型;齐穗期的CH4排放速率明显高于成熟期;日变化峰值均出现在一天中温度较高的15:00,最低值均出现在在温度偏低的7:00—9:00。稻田CH4排放通量的季节变化存在2个排放高峰,分别出现在生长最为旺盛的拔节孕穗期和收获前期。地下5cm温度和气温是影响CH4排放的重要因素。常规栽培、强化覆膜及强化无膜在水稻整个生长期内CH4排放总量分别为292.332,283.533和208.422kg·hm-2,强化栽培比常规栽培CH4排放总量减少了3.0%～28.7%,但增产效果不显著。     

改性橙皮静态吸附模拟废水中的Pb2+

采用异丙醇溶液改性橙皮,考察了模拟废水中初始Pb2+质量浓度、废水pH、改性橙皮加入量和吸附时间等因素对改性橙皮对模拟废水中的Pb2+吸附效果的影响。实验结果表明,在初始Pb2+质量浓度为20 mg/L、废水pH为4、改性橙皮加入量为8 g/L、吸附时间为80 min的条件下,改性橙皮对废水中Pb2+的去除率可达88.41%。经浓度为0.1 mol/L的HCl溶液再生后,改性橙皮再生循环使用4次时效果仍较好。改性橙皮对Pb2+的吸附动力学可用准二级动力学方程很好地描述。改性橙皮对Pb2+的吸附符合Langmuir等温吸附方程,表明改性橙皮对Pb2+的吸附以单分子层吸附为主。