Graphene TiO2 nanocomposites with high photocatalytic activity for the degradation of sodium pentachlorophenol

A series of graphene–TiO2photocatalysts was synthesized by doping TiO2 with graphene oxide via hydrothermal treatment. The photocatalytic capability of the catalysts under ultraviolet irradiation was evaluated in terms of sodium pentachlorophenol（PCP-Na） decomposition and mineralization. The structural and physicochemical properties of these nanocomposites were characterized by X-ray diffraction, N2adsorption–desorption, transmission electron microscopy, scanning electron microscopy, Ultraviolet–visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectra, and Fourier-transform infrared spectroscopy. The graphene–TiO2nanocomposites exhibited higher photocatalytic efficiency than commercial P25 for the degradation of PCP-Na, and 63.4% to 82.9% of the total organic carbon was fully mineralized. The improved photocatalytic activity may be attributed to the accelerated interfacial electron-transfer process and the significantly prolonged lifetime of electron-hole pairs imparted by graphene sheets in the nanocomposites. However,excessive graphene and the inhomogeneous aggregation of TiO2 nanoparticles may decrease photodegradation efficiency.     

国内石化企业过程安全管理对标分析

在参与美国化工过程安全中心(CCPS)过程安全管理对标的基础上,调研国际石化企业过程安全管理标准和实践,编制对标准则,对国内典型石化企业现场信息进行收集及对标,分析国内过程安全管理在工艺危害分析、设施完整性、变更管理、过程安全绩效指标、培训等方面存在的差距。     

过程安全管理要素——标准符合性研究

介绍了标准符合性要素的关键控制点和CCPS对该要素的要求,对比了国内外炼化企业在该要素的做法和差距,提出了建立书面程序、明确负责人、监控变更、合规性评价和培训5个方面的建议。     

某油品销售企业油库质检岗位职业病危害现状调查

调查了某油品销售企业质检岗位接触各类职业病危害因素情况,结合工作场所职业病危害因素日常监测结果和作业人员职业健康检查结果,探讨了职业病危害因素对作业人员健康的影响。     

河流穿越施工的环境风险分析研究——油气管道大开挖及河流穿越

针对油气管道大开挖河流穿越施工影响周边环境问题,在分析大开挖河流穿越施工对空气环境、水环境、声环境、生态环境风险的基础上,以某条输气管道大开挖穿越河流部分为例,建立了环境风险影响评价指标,采用了一种改进的灰色关联分析法确定了大开挖河流穿越施工造成的环境风险影响因素权重,得出该类型施工对环境影响的主要风险因素,并提出了相应的降低环境影响的风险控制措施。     

果蔬罐头生产废水治理工程设计研究

采用接触氧化-SBR工艺对果蔬罐头生产废水进行治理,其工艺抗冲击负荷能力强,抗污泥膨胀性能较好,对水质水量变化的适应性强。本文对该公司废水来源及水质、废水处理工艺流程及其特点、主要构筑物及其设备参数、工程运行效果做出了详细的分析和讲解。试验研究表明,工艺运行稳定、出水水质较好,能够满足《污水综合排放标准》(GB 8978-1996)中的一级排放要求。     

某省高危含砷爆炸物污染农田评价及分布研究

利用不同的评价标准和方法评价了吉林省某地含砷高危爆炸物造成的砷污染,同时借助GIS软件绘制了砷污染指数分布图。结果表明:以土壤环境背景值的上限值为评价标准,平均污染累积指数为2.61,最大为65.38,约57.38%的土壤受到人为外源砷的干扰;以(GB 15618-2008)中砷的二级标准作为评价标准,平均污染指数为1.01,最大污染指数达15.27,超标率为23.87%,表明该区存在严重的砷污染;地累积指数污染评价结果也表明该地存在明显的外源砷污染,受到污染的比例达41.57%;3种评价方法结果基本一致。污染指数分布表明,该地重污染区集中在中部区域,并形成了一个西北-东南方向分布的污染带。     

码头港作机械大气污染物排放清单研究

目前,国内对于港口港作机械的大气污染物排放计算方法尚未开展深入研究。在国内外文献综合分析的基础上,结合上海港各类港作机械现状调研结果,对港作机械污染物排放计算方法进行了上海本地化校正,建立了2010年上海港码头港作机械大气污染物排放清单,并提出相应的排放减排措施和进一步完善排放计算方法的思路。     

On-board measurement of particle numbers and their size distribution from a light-duty diesel vehicle: Influences of VSP and altitude

In this study, the particle size-resolved distribution from a China-3 certificated light-duty diesel vehicle was measured by using a portable emission measurement system (PEMS). In order to examine the influences of vehicle specific power (VSP) and high-altitude operation, measurements were conducted at 8 constant speeds, which ranged from 10 to 80 km/hr at 10 km/hr intervals, and two different high altitudes, namely 2200 and 3200 m. The results demonstrated that the numbers of particles in all size ranges decreased significantly as VSP increased when the test vehicle was running at lower speeds (< 20 km/hr), while at a moderate speed (between 30 and 60 km/hr), the particle number was statistically insensitive to increase VSP. Under high-speed cruising conditions, the numbers of ultrafine particles and PM_2.5 were insensitive to changes in VSP, but the numbers of nanoparticles and PM₁₀ surged considerably. An increase in the operational altitude of the test vehicle resulted in increased particle number emissions at low and high driving speeds; however, particle numbers obtained at moderate speeds decreased as altitude rose. When the test vehicle was running at moderate speeds, particle numbers measured at the two altitudes were very close, except for comparatively higher number concentrations of nanoparticles measured at 2200 m.     

Constructed wetlands for wastewater treatment in cold climate — A review

Constructed wetlands (CWs) have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option worldwide. However, the application of CW for wastewater treatment in frigid climate presents special challenges. Wetland treatment of wastewater relies largely on biological processes, and reliable treatment is often a function of climate conditions. To date, the rate of adoption of wetland technology for wastewater treatment in cold regions has been slow and there are relatively few published reports on CW applications in cold climate. This paper therefore highlights the practice and applications of treatment wetlands in cold climate. A comprehensive review of the effectiveness of contaminant removal in different wetland systems including: (1) free water surface (FWS) CWs; (2) subsurface flow (SSF) CWs;and (3) hybrid wetland systems, is presented. The emphasis of this review is also placed on the influence of cold weather conditions on the removal efficacies of different contami-nants. The strategies of wetland design and operation for performance intensification, such as the presence of plant, operational mode, effluent recirculation, artificial aeration and in-series design, which are crucial to achieve the sustainable treatment performance in cold climate, are also discussed. This study is conducive to further research for the understanding of CW design and treatment performance in cold climate.