Time domain reflectometry measured moisture content of sewage sludge compost across temperatures

Time domain reflectometry (TDR) is a prospective measurement technology for moisture content of sewage sludge composting material; however, a significant dependence upon temperature has been observed. The objective of this study was to assess the impacts of temperature upon moisture content measurement and determine if TDR could be used to monitor moisture content in sewage sludge compost across a range of temperatures. We also investigated the combined effects of temperature and conductivity on moisture content measurement. The results revealed that the moisture content of composting material could be determined by TDR using coated probes, even when the measured material had a moisture content of 0.581 cm³ cm^?3, temperature of 70 °C and conductivity of 4.32 mS cm^?1. TDR probes were calibrated as a function of dielectric properties that included temperature effects. When the bulk temperature varied from 20 °C to 70 °C, composting material with 0.10–0.70 cm³ cm^?3 moisture content could be measured by TDR using coated probes, and calibrations based on different temperatures minimized the errors.     

Atmospheric emission of polychlorinated biphenyls from multiple industrial thermal processes

In this study, field measurements were conducted to estimate and characterize the atmospheric emission levels and profiles of polychlorinated biphenyls (PCBs) from multiple industrial thermal processes. The emission levels and profiles of PCBs from five types of thermal processes at twenty-three plants were studied and compared with eight processes reported in our previous studies. Correlation analysis was preformed to identify a marker congener for emission of ΣPCB. A significant correlation was observed between congener CB-118 and ΣPCB (R² = 0.65 and p < 0.01), which suggests that CB-118 is a good marker congener for emission of ΣPCB. The profiles of PCBs emitted from the thirteen thermal processes were compared, and this information could be used for studying source–receptor relationships and identifying the specific sources of PCBs. To prioritize the sources for control, the concentrations of PCBs from thirteen industrial thermal sources were compared. The PCB concentrations from secondary zinc smelting and thermal wire reclamation were about one to three order magnitude higher than those of other sources, which suggests that these two sources be given priority in PCB source control. Finally, the atmospheric emission factors of PCBs from the thirteen industrial sources were summarized, and these data will be useful for developing an integrated emission inventory of PCBs.     

La2O3—ZrO2缺陷萤石型燃烧催化剂的制备

缺陷萤石型Ｌａ２Ｏ３－ＺｒＯ２固溶体的催化燃烧活性受制备条件的影响，本文通过对其共沉淀前体的表面结构和热分解过程的分析，发现共沸蒸馏的办法可以有效地控制前体表面羟基的缩合过程，减少团聚，保持前体中金属离子均匀分散，为生成缺陷有序的烧结石型的Ｌａ２Ｚｒ２Ｏ７复氧化物提供了可能。复合氧化物固溶体的表面阳离子配置情况与样品的催化氧化性能密切相关，软团聚前体的烧结产物对甲烷燃烧反应具有更高的催化活性。     

浅谈陆上石油钻井现场安全监督的考核与管理

石油行业,特别是石油钻井行业历来被认为是个高风险、多事故的行业.受钻井公司HSE 管理委员会的委派,安全监督对所负责施工现场的QHSE 管理实施全员、全方位、全天候、全过程的监督管理;监督现场所有的施工单位、人员、施工作业严格执行钻井公司QHSE 管理体系的相关规定,对生产现场违章指挥、违章操作、违反劳动纪律及其它违反企业安全管理规章制度、体系文件的现象进行纠正、制止并给予经济处罚.为了规范安全监督人员的行为和管理工作,公正、合理地评价每位驻井安全监督的工作业绩和管理水平,应通过加大对安全监督的考核力度,激励安全监督人员加强理论知识的学习和责任心,不断提高生产现场的监督管理水平.     

Characterization of livestock odors using steel plates, solid-phase microextraction, and multidimensional gas chromatography-mass spectrometry-olfactometry

Livestock operations are associated with emissions of odor, gases, and particulate matter (PM). Livestock odor characterization is one of the most challenging analytical tasks. This is because odor-causing gases are often present at very low concentrations in a complex matrix of less important or irrelevant gases. The objective of this project was to develop a set of characteristic reference odors from a swine barn in Iowa and, in the process, identify compounds causing characteristic swine odor. Odor samples were collected using a novel sampling methodology consisting of clean steel plates exposed inside and around the swine barn for < or =1 week. Steel plates were then transported to the laboratory and stored in clean jars. Headspace solid-phase microextraction was used to extract characteristic odorants collected on the plates. All of the analyses were conducted on a gas chromatography-mass spectrometry-olfactometry system where the human nose is used as a detector simultaneously with chemical analysis via mass spectrometry. Multidimensional chromatography was used to isolate and identify chemicals with high-characteristic swine odor. The effects of sampling time, distance from a source, and the presence of PM on the abundance of specific gases, odor intensity, and odor character were tested. Steel plates were effectively able to collect key volatile compounds and odorants. The abundance of specific gases and odor was amplified when plates collected PM. The results of this research indicate that PM is major carrier of odor and several key swine odorants. Three odor panelists were consistent in identifying p-cresol as closely resembling characteristic swine odor, as well as attributing to p-cresol the largest odor response out of the samples. Further research is warranted to determine how the control of PM emissions from swine housing could affect odor emissions.     

Study Progress and Trends of Strategic Environmental Assessment in China

Abstract

Strategic environmental assessment (SEA) in China has developed rapidly since it was introduced into China in the 1990s. Chinese government promulgated the Environmental Impact Assessment Law of China (hereinafter referred to as the EIA Law) in 2002. In this law, it is stipulated clearly that regional and sector plans should be assessed. Through investigating materials and analyzing literatures, this article analyses the practical and academic study achievements of SEA in China that have been achieved since the EIA Law was implemented, probes into the current situation of the main level of SEA in China—plan EIA, then summarizes the development characteristics, and eventually, puts forward the development trends of SEA in China. The research conclusions can offer the foundations for comprehending systematically the progress of SEA in China.     

镇海炼化公司作业场所健康促进效果评价

对镇海炼化公司所采取的石油化工作业场所作业人员健康促进措施进行了效果评价.评价结果发现,职工职业安全卫生知识知晓率、正确态度和行为形成率有所提高,健康促进工作初见成效.     

Reliability analysis of subsea blowout preventer control systems subjected to multiple error shocks

Two configurations of subsea blowout preventer (BOP) distributed control systems, which are triple modular redundancy (TMR) control system and double dual modular redundancy (DDMR) control system, are presented. With respect to common-cause failures, the performances of the two systems are evaluated by using Markov method with multiple error shock model. Due to the complexity, each system is split into three independent modules, and the corresponding Markov models are proposed subsequently. The probability of failure on demand, availability and reliability of the systems are evaluated by merging the independent Markov modules by Kronecker product approach. The results indicate that a same safety integrity level of SIL3 can be attained for the two configurations, which satisfies the requirement of subsea BOP control system, even though both of them have some advantages and shortcomings. In addition, for TMR control system, the effects of multiplicity distribution of multiple error shock and mean time to repair on reliability performances are studied.     

燃油流量对防火试验火焰特征的影响

为了研究燃油流量对防火试验火焰特征的影响,为防火试验方案的设计提供参考和指导,采用Ansys Fluent软件对NexGen燃烧器进行三维定常数值模拟,分析了不同燃油流量条件下的火焰特征。结果表明:燃油流量对火焰最高温度和火焰形状几乎没有影响,但对火焰长度、监测面上温度分布、7个测量点的平均温度和热流密度有很大影响,通过分析各燃油流量条件下的火焰特征,发现当空气流量为35.8 g/s时,燃油流量在2.0~2.11 g/s——即余气系数为1.15~1.22时,能够用于防火试验。     

Environmental contamination from electronic waste recycling at Guiyu, southeast China

The disposal, recycling, and part salvaging of discarded electronic devices such as computers, printers, televisions, and toys are now creating a new set of waste problems. This study is aimed at identifying the sources and quantifying the pollution levels generated from electronic waste (e-waste) activities at Guiyu, Guangdong Province, China, and their potential impacts on the environment and human health. The preliminary results indicate that total polycyclic aromatic hydrocarbons (PAHs) in soil obtained from a printer roller dump site was 593 μg/kg dry weight (dry wt.) and in sediment from a duck pond, the PAH concentration was 514 μg/kg (dry wt.). Sediment from the Lianjiang River was found to be contaminated by polychlorinated biphenyls (743 μg/kg) at a level approaching three times the Canadian Environmental Quality Guidelines probable effect level of 277 μg/kg. Total mono- to hepta-brominated diphenyl ether homologue concentrations (1140 and 1169 μg/kg dry wt.) in soils near dumping sites were approximately 10–60 times those reported for other polybrominated diphenyl ether-contaminated locations in the world. In-house study on the open burning of cable wires showed extremely high levels of polychlorinated dibenzo-p-dioxins and dibenzofurans resulting in 12419 ng toxic equivalents (TEQ)/kg of waste input and 15 610 ng TEQ/kg for two separate tests, respectively, which were about three orders of magnitude higher than those for the open burning of household waste. High levels of Cu (712, 528, and 496 mg/kg), exceeding the new Dutch list action value, were determined for soil near the printer roller dumping area, sediment from Lianjiang River, and soil from a plastic burn site, respectively. A more thorough study is underway to elucidate the extent of contamination of toxic pollutants in different ecological compartments to establish whether these pollutants are bioaccumulated and biomagnified through food chains. Assessments of human health impacts from oral intake, inhalation, and dermal contact will be subsequently investigated. An erratum to this article is available at.