Visual MODFLOW在露天矿地下水模拟中的应用

用Visual MODFLOW建立了某露天矿地下水数值模型,运用其跟踪模拟(MODPATH)子模块及溶质运移模拟(MT3D)子模块对该露天矿地下水的水质点示踪和三维污染羽进行了模拟,模拟结果有助于识别该矿露天开采对地下水污染的污染源及污染途径,为预测露天矿开采期间地下水位及水质的变化,采用的监测与预保护措施提供了决策依据。     

Source attributions of heavy metals in rice plant along highway in Eastern China

Air and soil pollution from traffic has been considered as a critical issue to crop production and food safety, however, few efforts have been paid on distinguish the source origin of traffic-related contaminants in rice plant along highway. Therefore, we investigated metals (Pb, Cd, Cr, Zn and Cu) concentrations and stable Pb isotope ratios in rice plants exposed and unexposed to highway traffic pollution in Eastern China in 2008. Significant differences in metals concentrations between the exposed and unexposed plants existed in leaf for Pb, Cd and Zn, in stem only for Zn, and in grain for Pb and Cd. About 46% of Pb and 41% of Cd in the grain were attributed to the foliar uptake from atmosphere, and there were no obvious contribution of atmosphere to the accumulations of Cr, Zn and Cu in grain. Except for Zn, all of the heavy metals in stem were attributed to the root uptake from soil, although significant accumulations of Pb and Cd from atmosphere existed in leaf. This indicated that different processes existed in the subsequent translocation of foliar-absorbed heavy metals between rice organs. The distinct separation of stable Pb isotope ratios among rice grain, leaf, stem, soil and vehicle exhaust further provided evidences on the different pathways of heavy metal accumulation in rice plant. These results suggested that further more attentions should be paid to the atmospheric deposition of heavy metals from traffic emission when plan crop layout for food safety along highway.     

地下水六价铬运移的仿真及场地修复限值探讨

根据渗流理论,考虑地下水中水头变化的影响,利用COMSOL软件,对六价铬在地下水中的运移进行数值模拟,得到地下水压力水头和六价铬在地下水中的迁移变化规律,为六价铬对地下水的污染研究和预测提供重要的分析数据。并借此计算得出场地地下水的修复指导限值为3.17 mg/kg。     

垃圾填埋场渗滤液污染控制技术研究进展

垃圾渗滤液是垃圾填埋过程中产生的一种有机浓度高、成分复杂的污水,对周边生态环境和人们身心健康影响极大。本文详细介绍了垃圾渗滤液的水质特征及国内外各类控制技术,并进行了对比分析,提出是源头控制重点,处理是保障的污染控制新思路。     

矿化垃圾生物反应床处理渗滤液技术

针对矿化垃圾筛分后<15mm组分性质进行研究,并以该组分为填料设计制造矿化垃圾生物反应床处理渗滤液,研究表明,矿化垃圾具有较大的吸附比表面积,较强的离子交换容量,较高的有机质含量,含有种类和数量可观的微生物种群可供生物降解作用,是很好的污水处理生物介质。工程应用表明:渗滤液经过三级矿化垃圾生物反应床串联处理后,CODCr和NH4+-N的总去除率达到90%和95%以上,可稳定达到国家二、三级渗滤液排放标准。     

以监测预报工作为导向推进数字化监测教学

地震预测的发展方向,是从协同的观点,多层面地统筹考虑地震监测体系的建设,实现基础研究与实际地震预测工作的结合.本文从如何利用原有监测资料、连续前兆监测数据处理系统的建立、前兆监测体系数据报送体系等地震监测工作环节,分析地震监测教学如何与监测工作方向相一致,并对教学改革如何结合台站技术人员更新提出了几点看法.     

如何建立多层次HSE管理体系的PDCA循环模式

PDCA循环模式是HSE管理体系运行的最基本方式,也是实现体系绩效螺旋式上升的重要手段.在体系运行的过程中,经过PDCA等各个环节以及各环节涉及到的诸多要素的不断发展与完善,体系的目标与方针得以实现.从管理体系实际运行的角度来看,整个体系运行过程中的PDCA循环又可以分为以下层次:单要素间某几个管理方面的相互影响与作用;几个要素之间形成的PDCA循环;大部分要素(关键要素)之间的作用;整个体系的PDCA循环.这几层次的循环模式也是相互交叉相互作用的.现以表1所涉及的工作为例,探讨这几个层次PDCA循环的相关性.     

现场安全监督是安全工作的核心

随着石油工业的发展和科学技术的进步,在油气开发和加工的生产中已形成了一套完善、先进的工艺技术,但在生产现场的安全管理方面仍存在着许多薄弱环节和诸多不安全因素.这些不安全因素将导致各类事故的发生,直接威胁着油田的安全生产.     

Mo-modified Pd/Al2O3 catalysts for benzene catalytic combustion

Mo-modified Pd/Al2O3catalysts were prepared by an impregnation method and tested for the catalytic combustion of benzene. The catalysts were characterized by N2 isothermal adsorption, X-ray diffraction（XRD）, X-ray photoelectron spectroscopy（XPS）, temperatureprogrammed desorption of NH3（NH3-TPD）, H2temperature-programmed reduction（H2-TPR）, and high-angle annular dark-field scanning transmission electron microscopy（HAADF-STEM）. The results showed that the addition of Mo effectively improved the activity and stability of the Pd/Al2O3catalyst by increasing the dispersion of Pd active components, changing the partial oxidation state of palladium and increasing the oxygen species concentration on the surface of catalyst. In the case of the Pd-Mo/Al2O3catalyst,benzene conversion of 90% was obtained at temperatures as low as 190°C, which was 45°C lower than that for similar performance with the Pd/Al2O3catalyst. Moreover, the 1.0% Pd-5% Mo/Al2O3catalyst was more active than the 2.0% Pd/Al2O3catalyst. It was concluded that Pd and Mo have a synergistic effect in benzene catalytic combustion.     

Microbial community functional structure in response to micro-aerobic conditions in sulfate-reducing sulfur-producing bioreactor

Limited oxygen supply to anaerobic wastewater treatment systems had been demonstrated as an effective strategy to improve elemental sulfur(S0) recovery, coupling sulfate reduction and sulfide oxidation. However, little is known about the impact of dissolved oxygen(DO) on the microbial functional structures in these systems. We used a high throughput tool(GeoChip) to evaluate the microbial community structures in a biological desulfurization reactor under micro-aerobic conditions(DO: 0.02–0.33 mg/L). The results indicated that the microbial community functional compositions and structures were dramatically altered with elevated DO levels. The abundances of dsrA/B genes involved in sulfate reduction processes significantly decreased(p 0.05, LSD test) at relatively high DO concentration(DO: 0.33 mg/L). The abundances of sox and fccA/B genes involved in sulfur/sulfide oxidation processes significantly increased(p 0.05, LSD test) in low DO concentration conditions(DO: 0.09 mg/L) and then gradually decreased with continuously elevated DO levels. Their abundances coincided with the change of sulfate removal efficiencies and elemental sulfur(S0) conversion efficiencies in the bioreactor. In addition, the abundance of carbon degradation genes increased with the raising of DO levels, showing that the heterotrophic microorganisms(e.g., fermentative microorganisms) were thriving under micro-aerobic condition. This study provides new insights into the impacts of micro-aerobic conditions on the microbial functional structure of sulfatereducing sulfur-producing bioreactors, and revealed the potential linkage between functional microbial communities and reactor performance.