Probabilistic seismic multi-hazard loss estimation of Iran gas trunklines

The location of Iran in addition to holding the world's second-largest gas reserves, makes this country an important transporter of natural gas in the world. Moreover, Iran is a country that suffers from hazards associated with frequent destructive earthquakes, which can severely damage buried gas transmission networks, different losses correspond to individuals, social, environmental, and the property is expected. Therefore, it is essential to identify potential seismic hazards and assess their risk will be induced to the country. This paper is performing a comprehensive probabilistic loss assessment of the entire network of the Iran Gas Trunklines (IGAT) due to seismic multi-hazard failure using GIS-based analyses and the HAZUS methodology proposed by FEMA. In the current study, all kinds of seismic hazards are considered for analyzing the IGAT as a spatially-distributed infrastructure for being exhaustive. As a result, seismic hazard maps, repair rate maps, the IGAT expected damage state map, and the IGAT economic loss map are presented. As an example of the outputs of this study, the economic loss of the IGAT is predicted by up to 380 US dollars per segment, which is related to the most vulnerable segments of the pipelines. The outputs of the current research not only can help to plan for mitigating the probable seismic losses but also can help anyone, who are involved in designing and developing new gas transmission lines, to design new trunklines with a more degree of safety.     

脉冲通风法治理“U”型工作面上隅角瓦斯积聚的理论及技术探讨

针对生产现场出现的“U”型采煤工作面上隅角瓦斯积聚问题 ,科学地分析了其形成的原因及目前解决上隅角瓦斯积聚的常用方法 ,提出了旋转脉冲法解决此问题的新途径 ,并进行了详细的理论分析。通过现场实验 ,验证了用旋转脉冲法解决上隅角瓦斯积聚是有效的、可行的。     

攀钢120t转炉屋顶电除尘器集水槽的设计与改进

集水槽是屋顶电除尘器的主要组成部件之一,也是屋顶电除尘器与常规电除尘器结构设计的重要区别之一。文中叙述了在屋顶电除尘器设计过程中对此部件设计所要考虑的问题及设计方法,并对其需改进之处提出了展望。     

PTR-MS measurements and analysis of models for the calculation of Henry's law constants of monosulfides and disulfides

Sulfides are known for their strong odor impact even at very low concentrations. Here, we report Henry’s law constants (HLCs) measured at the nanomolar concentration range in water for monosulfides (dimethylsulfide, ethylmethylsulfide, diethylsulfide, allylmethylsulfide) and disulfides (dimethyldisulfide, diethylsulfide, dipropylsulfide) using a dynamic stripping technique coupled to Proton Transfer Reaction-Mass Spectrometry (PTR-MS). The experimental data were compared with literature values and to vapor/solubility calculations and their consistency was confirmed employing the extra-thermodynamic enthalpy-entropy compensation effect. Our experimental data are compatible with reported literature values, and they are typically lower than averaged experimental literature values by about 10%. Critical comparison with other freely available models (modeled vapor/solubility; group and bond additivity methods; Linear Solvation Energy Relationship; SPARC) was performed to validate their applicability to monosulfides and disulfides. Evaluation of theoretical models reveals a large deviation from our measured values by up to four times (in units of M atm⁻¹). Two group contribution models were adjusted in view of the new data, and HLCs for a list of sulfur compounds were calculated. Based on our findings we recommend the evaluation and adaption of theoretical models for monosulfides and disulfides to lower values of solubility and higher values of fugacity.     

Recovery of volatile fatty acids via membrane contactor using flat membranes: Experimental and theoretical analysis

Volatile fatty acid (VFA) separation from synthetic VFA solutions and leachate was investigated via the use of a membrane contactor. NaOH was used as a stripping solution to provide constant concentration gradient of VFAs in both sides of a membrane. Mass flux (12.23 g/m² h) and selectivity (1.599) observed for acetic acid were significantly higher than those reported in the literature and were observed at feed pH of 3.0, flow rate of 31.5 ± 0.9 mL/min, and stripping solution concentration of 1.0 N. This study revealed that the flow rate, stripping solution strength, and feed pH affect the mass transfer of VFAs through the PTFE membrane. Acetic and propionic acid separation performances observed in the present study provided a cost effective and environmental alternative due to elimination of the use of extractants.     

Long Term Monitoring of Hydrocarbon Contamination Using Multi-Level Vapor Phase Piezometers

This study evaluated the feasibility of supplementing groundwater monitoring protocols by assessing the vadose zone for the extent of residual subsurface contamination. The study also characterized the response of the soil gas signatures with respect to different soil types and degrees of contamination. A field study was conducted at a former gasoline vending station located in Ottawa, Canada. The current state of contamination was determined by analysis of soil samples taken from boreholes. A series of 10 nested soil gas wells with monitoring depths of 0.75, 1.5, 2.25 and 3.0 m were then installed. Using these wells, soil gas surveys were performed at regular intervals over an extended period to quantify Gaseous TPH (TPH g ), oxygen and carbon dioxide concentrations in the soil gas. Results indicate that soil gas wells located near the source term exhibited characteristic soil gas signatures and significant fluctuations in TPH g , oxygen, and carbon dioxide concentrations with time. Soil gas wells located beyond the soil contamination demonstrated limited correlation between TPH g , oxygen and carbon dioxide concentrations and decreased seasonal variability.     

Determination of indicator polychlorinated biphenyls (PCBs) by gas chromatography–electron capture detector

An effective method for determination of indicator polychlorinated biphenyls (PCBs) has been validated using gas chromatography (GC) equipped with electron capture detector (ECD). The GC–ECD method was validated by determining the linear range (working range) for determination of the compounds, minimum detectable quantities (MDQ), the precision and accuracy of the method for the analysis of the compounds. MDQ obtained for the compounds ranges from 0.0005 to 0.002 ng. Indeed the method was found to be more sensitive as the number of chlorine atoms attached to the biphenyl increases. The precision and accuracy of the GC method validated ranges from 2.4% to 14.5% and −7.0% to 14.6% respectively. Coefficient of variation associated with the repeatability of the retention times and corresponding peak areas was found to be 0.0001–0.0007 for the retention times and 0.0014–0.059 for the peak areas. Percentage recoveries for the compounds were in the range of 95.7–101.0%. The validated method was then applied to determine levels of indicator PCBs in sediments sampled from eleven sampling points along the Lake Bosuntwi in Ghana and the highest PCB load of 19.17 ng g⁻¹ was recorded at Pipie No. 2. PCB 52 and PCB 101 were found to be the most ubiquitous indicator PCBs in the study area, both with 90.91% occurrence.     

Residues of organochlorine pesticides and PCBs in some Brazilian municipal solid waste compost

Persistent organic pollutants (POPs), organochlorine pesticides and polychlorinated biphenyls (PCBs), listed as per the Stockholm Convention (α -HCH, β -HCH, γ -HCH, p,p′-DDT, o,p′-DDT, p,p′-DDD, p,p′-DDE, aldrin, endrin, dieldrin, PCBs 28, 52, 118, 138, 153, and 180), were analyzed in municipal solid waste (MSW) compost samples from three different Brazilian composting plants located in three São Paulo State cities: Araras, Araraquara and São Paulo (Vila Leopoldinha). Quantitative and qualitative analyses were carried out using gas chromatography electron capture detection (GC-ECD) and gas chromatography mass spectrometry (GC-MS) (Ion Trap, electron impact ionization), respectively. The samples were analyzed in triplicate and the target POPs were not detected by GC-ECD. Twelve pollutants were identified in two samples when qualitative analysis (GC-MS) was used (β -HCH, γ -HCH, p,p′-DDT, o,p′-DDT, p,p′-DDD, and p,p′-DDE, PCBs 28, 118, 138, 153 and 180). The composting process has advantages such as urban solid waste reduction and landfill life-span increase, however the MSW compost quality, which can be utilized for agricultural purposes, should be evaluated and be controlled. This kind of study is the first step in making available information to answer questions regarding MSW compost for sustainable agricultural use, such as the pollutants accumulation in soil and in groundwater, and plants uptake.     

动态稀释法在汽车涂装行业固定污染源挥发性有机物测定中的应用

介绍了固定污染源中挥发性有机物(VOCs)的主要采样方法,并重点介绍了动态稀释法在固定污染源中采样的应用。采用动态稀释法取样,对某汽车企业涂装车间的排放废气进行了定性分析,并对其中主要的10种VOCs进行了定量分析。研究了方法测定的稳定性,10种化合物相对标准偏差为9%~32%,符合工况变动范围。将不同采样时间及不同吸附材料的测定结果与在线监控数据进行比较,结果显示动态稀释法的测定结果均在实际工况波动范围内,说明该方法能够较好地满足汽车涂装行业VOCs的采样要求。     

动态固相微萃取-气相色谱质谱法测定水中多种异味有机物

采用动态固相微萃取技术富集水样中2-异丙基-3-甲氧基吡嗪、2-异丁基-3-甲氧基吡嗪、2-MIB、β-环柠檬醛、2,4,6-三氯苯甲醚、GSM、α-紫罗酮和β-紫罗酮等8种异味有机物,并用气相色谱质谱法测定。通过优化试验条件,使方法在2. 00 ng/L～100 ng/L范围内线性良好,方法检出限为1. 0 ng/L～4. 4 ng/L。空白水样3个质量浓度水平的加标回收率为81. 0%～121%,6次测定结果的RSD为1. 7%～8. 9%。将该方法用于一水库实际水样的测定,结果 2-MIB、β-环柠檬醛、α-紫罗酮和β-紫罗酮检出,其余均为未检出。