内置渗透墙型生态塘处理农村生活污水的研究

通过在传统的生态塘中增设了一道活性渗透墙而改造成的内置渗透墙型生态塘。结果表明,内置渗透墙型生态塘对生活污水具有良好的处理效果,在水力负荷为0．05～0．1m^3／m^2·d之间时,即水力停留时间在10d～20d时,它对COD的去除率在60％以上,对TN的去除率在50％以上,对TP的去除率在75％以上。大大减轻了后序工艺的负担,减少了后序处理设施。从而缩小了整个生态塘系统的占地面积,节省了基建投资,是一种高效的适合农村生活污水处理的技术。     

Effects of 5-year application of municipal solid waste compost on the distribution and mobility of heavy metals in a Tunisian calcareous soil

It is obvious that the application of solid waste compost improves the soil fertility. These wastes, however, may also have some negative effects on the agricultural environment due to their metal content. This research aimed at evaluating the influence of Tunisian municipal solid waste compost and farmyard manure on some chemical properties and the distribution of heavy metals in a calcareous Tunisian soil (clayey–loamy soil). A field plot experiment, without vegetation, was installed since 1999 at the experimental farm of the Agronomic National Institute of Tunis (INAT) in the region of Mornag (20 km south of Tunis, Tunisia). During 5 years, the field received yearly the following treatments: 0, 40, 80 and 120 t/ha of municipal solid waste compost and 0, 40 and 120 t/ha of manure. The fractionation of heavy metals in the soil was evaluated after 5 years using a sequential extraction procedure. The application of the two amendments was found to increase the content of organic matter, the total nitrogen content and the electrical conductivity, whereas it slightly decreased the soil pH. The addition of manure did not have a significant effect on the accumulation of heavy metals in the soil, whereas compost application increased the total concentration of heavy metals in the soil. The distribution of heavy metals between the different fractions in untreated and treated soils showed the residual fraction to be dominant, followed by the fraction bound to Fe and Mn oxides. The amount of Cu bound to the organic fraction increased with the application rate, which is probably caused by the formation of organic complexes. For the other metals, the increase of the association with organic matter is very limited. The application of compost moreover increases the amount of Zn associated with Fe and Mn oxides. The “Mobility Factor (MF)” was quite low and did not change after the 5-year application of the two organic amendments. It always remained lower than 10%, although for Cd it amounted to 17%.     

燃气系统漏损事故定性定量分析

以某城市的燃气事故为依据,结合各地的经验,对燃气系统漏损事故进行定性定量的统计分析。     

示范小城镇建设项目环境影响评价中的土壤污染问题

结合示范小城镇建设项目环境影响评价中土壤污染分析的特点,总结了该类环评项目中开展土壤污染评价的思路和方法。介绍区内企业土壤污染的排查方式,归纳不同行业土壤特征污染物的分类,指出土壤污染现状评价的标准,汇总各类受污染土壤的修复措施,并结合相关环保法律法规,对相关责任方的职责加以明确。     

Effects of UV/Ag-TiO2/O3 advanced oxidation on unicellular green alga Dunaliella salina: Implications for removal of invasive species from ballast water

The UV/Ag-TiO2/O3 process was investigated for ballast water treatment using Dunaliella salina as an indicator. Inactivation curves were obtained, and the toxicity of e uent was determined. Compared with individual unit processes using ozone or UV/Ag-TiO2, the inactivation e ciency of D. salina by the combined UV/Ag-TiO2/O3 process was enhanced. The presence of ozone caused an immediate decrease in chlorophyll a (chl-a) concentration. Inactivation e ciency and chl-a removal e ciency were positively correlated with ozone dose and ultraviolet intensity. The initial total residual oxidant (TRO) concentration of e uent increased with increasing ozone dose, and persistence of TRO resulted in an extended period of toxicity. The results suggest that UV/Ag-TiO2/O3 has potential for ballast water treatment.     

Numerical prediction of radiative heat transfer in reciprocating superadiabatic combustion in porous media

A numerical study of Reciprocating Superadiabatic Combustion of Premixed gases in porous media (hereafter, referred to as RSCP) is performed. In this system the transient combustion of methane-air mixture is stabilized in a porous media combustor by periodically switching flow directions. The mass, momentum, energy and species conservation equations are solved using a two-dimensional control volume method. Local thermal non-equilibrium between the gas and the solid phases is considered by solving separate energy equations for the two phases and coupling them through a convective heat transfer coefficient. The porous media is assumed to emit, absorb and isotropically scatter radiation. The influences of the dominating operating parameters, such as filtration velocity, equivalence ratio and half cycle on the temperature profile, heat release rate, radiant flux, radiant efficiency and combustion efficiency are discussed. The results show that coupling calculating of flow field, combustion reaction and volume radiation of the optically thick media is successively achieved and heat radiation plays an important role in the overall performance of the burner. The temperature profile inside the RSCP combustor has a typical trapezoidal shape and the profile of radiation flux is similar to sinusoidal shape. Compared with the conventional premixed combustion in porous medium, combustion behavior in RSCP combustor is superior, such as better thermal structure and higher radiation efficiency and combustion efficiency.     

V系列转基因银中杨(Salix alba var Tristis)与非转基因组长势差异的初步分析

经对鄂尔多斯市达拉特旗树林召镇的转基因试验林中的v系列转基因银中杨与非转基因对照组的生长性状的对比研究证明:该转基因系列具有较强的环境适应性,生长状况明显优于非转基因杨树。     

由博帕尔事故分析石化企业工艺安全管理

介绍了印度博帕尔农药厂异氰酸甲酯泄漏事故概况及其原因,并从工艺安全角度分析了事故教训,提出加强石化企业工艺安全管理的措施。     

钢筋混凝土偏心受压短柱尺寸效应研究

现行钢筋混凝土结构设计方法是基于小尺寸构件的试验研究建立起来的,大尺寸构件的设计的科学性和合理性有待进一步研究.本文制作2组4根钢筋混凝土偏心受压短柱,偏心距为0.6h0,试件的截面几何尺寸分别为200 mm×200 mm、400 mm × 400 mm.研究相同偏心距下,不同尺寸的钢筋混凝土偏心受压短柱的破坏特征,极...     

基于能量的建筑结构抗震设计方法介绍

基于能量概念的抗震设计方法能较好地反映地震动三要素,特别是持续时间对结构引起的累积损伤破坏的综合影响,因此日益受到地震工程研究的重视.本文对地震作用下结构的总输入能量、结构总耗能的分配与分布、结构的耗能能力和具体设计方法等方面的研究现状进行了综合分析和介绍,为能量抗震方法的应用和推广提供参考.