Low-dose irradiation by electron beam for the treatment of high-SOx flue gas on a semi-pilot scale—Consideration of by-product quality and approach to clean technology

Attention has been focused on the treatment of lignite-fired flue gas in order to use lignite in an environmentally friendly way – (i) low-CO₂ emission, (ii) production of a valuable by-product, (iii) no discharge of wastewater, (iv) direct removal of SO₃ (strong toxicity), and (v) treatment of high SO₂ concentration. Based on these criteria, electron beam irradiation with ammonia injection was tested on a semi-pilot scale: 800 Nm³ h^?1 flow rate, 5500 ppm SO₂, 70 ppm NO_x, 22% flue gas moisture, and 75–80 °C at the reactor outlet.As an energy-saving measure, a low dose (5 kGy) of irradiation was applied: the problem lay in the by-product quality. It is considered that (NH₄)₂SO₃ and NH₄HSO₃ produced by thermal reactions are oxidized to form (NH₄)₂SO₄ (fertilizer) by an electron beam. However, not all reactions were complete because the by-product contained small amounts of H₂SO₄ and NH₂SO₃NH₄ (herbicide), so a vegetable pot test was performed to study the by-product quality: no adverse effect was observed. It is inferred from the pot test that slightly acidic soil may protect vegetables from disease and a small amount of NH₂SO₃NH₄ probably affects woody species and not herbaceous species.It is concluded that the electron beam system is noted as a multi-component pollution control process (removal of NO_x, SO₃, SO₂ and dioxins) and this system will contribute to environmentally friendly use of lignite as well as agricultural productivity via fertilizer supply.     

Enhanced NOx removal from flue gas by an integrated process of chemical absorption coupled with two-stage biological reduction using immobilized microorganisms

An integrated process of metal chelate absorption coupled with two stage bio-reduction using immobilized cultures has been proposed to continuously removal of NO_x, and the effects of SO₂, NO and O₂ concentration, gas/liquid flow rate on NO_x removal efficiency were investigated. Although nitrogen-containing components, such as Fe(II)EDTA-NO, NO₂^? and NO₃^? in the scrubbing solution, inhibited the bio-reduction of Fe(III)EDTA obviously, it was feasible to abate the inhibition effect by using the two stage bio-reduction system, and thus to improve NO_x removal efficiency. The removal efficiency decreased slowly with the increase of SO₂, O₂, NO concentration and gas flow rate, and increased with the increase of liquid flow rate. Continuously operating for 18 days, a high removal efficiency around 95% was reached by using the two-stage bio-reduction system with immobilized microorganisms, while the value decreased to 85% after 5 days of operation by using the suspended microorganisms, at a constant gas flow rate of 60 L/h containing 424–450 mg/m³ NO, 2428–2532 mg/m³ SO₂ and 3% O₂.     

上海工业街坊噪声对职工健康影响的研究和对策

作者对上海工业街坊固定源和流动源噪声进行了调查和测试,取得了大量的数据,找出了工业街坊中主要噪声源和噪声级的变化范围,提出了大城市工业区域噪声评价的方法并进行评价,得出各工业街坊噪声污染指数与评价等级。文章将处于此噪声等级下的职业工人和居民的职业病与人体健康状况,进行了特异性损伤与非特异性损伤的分析,并重点研究了纺织业等工业噪声对职工健康的影响。文章最后就工业街坊噪声污染治理对策,提出了合理工业布局和建立低噪声工业街坊的必要性。     

An improved method of removal for high concentrations of NO by electro-scrubbing process

In the Ag(II)/Ag(I) redox mediator integrated scrubber system, NO reacts with the Ag(II) ions produced by the electrochemical oxidation of Ag(I) in an electrochemical cell present in the scrubbing solution (aqueous HNO₃ acid) to form NO₂. This NO₂ is then absorbed into the scrubbing solution and degraded to nitrate. Numerous experimental runs were carried out to evaluate the feasibility of the integrated system to treat industrial waste gases containing high NO_x levels. The results showed that the levels of NO and NO_x removal increased with increasing Ag(II) loading and contact time. Under optimized conditions, 93.5% and 73.3% of the NO and NO_x, respectively, were removed by a single stage gas scrubber with 1.62 g L^?1 Ag(II) operating at 25 °C and atmospheric pressure.     

秦皇岛市重点工业企业VOCs排放及分布特征

工业企业挥发性有机物(VOCs)污染排放对大气环境影响日益突出,工业源VOCs污染防治成为环境保护的重点工作。为进一步提高秦皇岛市工业源挥发性有机物(VOCs)治理的科学性、针对性和有效性,对2019年秦皇岛市重点排污企业VOCs的排污量、区域分布、排放行业等进行了详细调查分析:秦皇岛市重点工业源VOCs排放总量为6875.83t,排放量最大的区域是秦皇岛经济技术开发区,占比51.1%;排放量最大的行业是交通运输设备制造业,占总排放量的33.5%;溶剂使用源的排放量最大,占比52.3%。     

Experimental study on biomass advanced reburning for nitrogen oxides reduction

Advanced reburning (AR) is effective for nitrogen oxides (NO_x) reduction, which integrates the basic reburning (BR) with the injection of nitrogen agents and additive compounds. The basic reburning of poplar, cornstalk, wheat-straw and peanut shell, is studied on a boiler simulator facility (BSF). The influence of operating parameters and the synergistic effect of the injection of ammonia, urea or/and sodium carbonate on NO_x reduction are investigated. The results show that an efficiency of 54–67% NO_x reduction could be achieved during the basic reburning process under the optimum operating conditions and the efficiency would be increased if nitrogen agent is injected with the over-fire air or into the burnout zone. Further, co-injection of sodium carbonate with the nitrogen agent could make the NO_x reduction process more thorough. On the whole, 85–92% NO_x reduction could be achieved during the advanced reburning process with a reburning fuel heat input of 15–20%.     

Trends in bicycle-related injuries,hospital admissions,and deaths in the USA 1997–2013

Objective: Cycling is associated with numerous health benefits but also the risk of traumatic injury. Recent data demonstrate an increase in overall cycling injuries as well as hospital admissions from 1997 to 2013 in the United States. We seek to better understand the causes of the increase in cycling injuries and hospital admissions.

Methods: Data regarding cycling-related injuries and hospital admissions were obtained from the National Electronic Injury Surveillance System (NEISS). Participation data were derived from the National Sporting Goods Association Sports Participation Survey, and fatality data were collected from the Fatality Analysis Reporting System (FARS). Population estimates were obtained using a complex survey design. Linear regression was used to evaluate univariate relationships between cycling injuries, hospital admissions, deaths, and participation. To evaluate factors associated with hospital admission, we developed a multivariable logistic regression model that included year, age, gender, body part injured, and injury type (i.e., contusion, fracture, or laceration).

Results: The number of individuals who cycle did not change significantly over time, but there was a substantial increase in cycling-related injuries, leading to an increase in per participant injuries from 701/100,000 in 1997 to 1,164/100,000 in 2013. When the injuries were evaluated by age group, younger cyclists have an increased risk for injury, whereas the rise in injuries among older cyclists stemmed from an increase in ridership rather than a unique susceptibility to injury. Trends in hospital admissions and fatalities appeared to be driven by increases in the older age groups. In the multivariable model evaluating factors related to hospital admission, the odds of hospital admission increased for each decade after age 25, as well as male gender and body part injured.

Conclusion: On a per participant basis, the rate of cycling-related injuries and hospital admissions increased between 1997 and 2013. This trend likely reflects a combination of shifting demographics among cyclists with an increase in older cyclists who are at increased risk of severe injury.     

Kinetic and 2D reactor modeling for simulation of the catalytic reduction of NOx in the monolith honeycomb reactor

Emission of NO_x is of primary environmental concern in the oil sands industry. Selective catalytic reduction (SCR) is one of the best NO_x reduction technologies. The present study discusses the testing of a mechanistic kinetic model for the SCR of NO_x to describe the kinetics of V₂O₅/TiO₂ catalysis at atmospheric pressure and a temperature of 623 K in a monolith honeycomb reactor. The modeling results impart insight into the significance of the diffusion with reaction steps and guidance for optimal monolith design for SCR. The validated expression would predict the conversion performance of the catalysts for different values of temperature inlet and ammonia concentration. A good agreement between experimental and model results has been obtained. A heterogeneous numerical model consisting of coupled mass and momentum balance equations was solved using the finite elements method without neglecting the axial dispersion term. The operating range for the catalyst relies on the NO conversion and emission. The optimum operating range for the best performance of the reactor is discussed.     

Thermal hazard and decomposition kinetics of 1-butyl-2,3-dimethylimidazolium nitrate via TGA/DSC and FTIR

1-Butyl-2,3-dimethylimidazolium nitrate ([Bmmim][NO₃]), a kind of versatile and novel ionic liquids, is widely applied in the modern petrochemical industry. Nevertheless, its thermal hazard safety data at high temperature or thermal disturbance conditions are currently unavailable. Therefore, this study aimed to characterize the thermal risk of [Bmmim][NO₃] through auto-ignition temperature measurements, flash point analysis, thermal gravimetric analysis/differential scanning calorimetry (TGA/DSC), TGA-Fourier transform infrared spectroscopy (TGA-FTIR) and thermal decomposition kinetics analysis. Additionally, [Bmmim][NO₃] was examined using isothermal thermogravimetric analysis at different temperatures (220, 230, 240, 250, 260 and 270 °C). The experimental results show that the flash point of [Bmmim][NO₃] is 305.70 ± 9.30 °C and the auto-ignition temperature is 341.00 ± 21.60 °C with an ignition delay time of 8.6 s. In addition, using the nitrogen atmosphere TGA data to calculate the activation energy according to the Friedman, Kissinger and Flynn-Wall-Ozawa methods, roughly the same results were obtained. Finally, TGA-FTIR results show that [Bmmim][NO₃] produced acetylene, butane, butanol and carbon dioxide during the thermal decomposition process. This study could provide data support and some guidance for the thermal hazard assessment and safety control of [Bmmim][NO₃] during its use and storage.     

Combustion products toxicity risk assessment in an offshore installation

Products of a hydrocarbon fire accident have both chronic and acute health effects. They cause respiratory issues to lung cancer. While fire is the most frequent phenomenon among the offshore accidents, predicting the contaminants’ concentration and their behavior are key issues. Safety measures design, such as ventilation and emergency routes based only on predicted contaminants’ concentration seems not to be the best approach. In a combustion process, various harmful substances are produced and their concentration cannot be added. The time duration that any individual spends in different locations of an offshore installation also varies significantly. A risk-based approach considers the duration a person is exposed to contaminants at various locations and also evaluates the hazardous impacts. A risk-based approach has also an additivity characteristic which helps to assess overall risk.Through the current study, an approach is proposed to be used for risk assessment of combustion products dispersion phenomenon in a confined or semi-confined facility. Considering CO, NO₂ and CH₄ as the contaminants of concern, the dispersion of the substances over the layout of the facility after a LNG fire is modeled. Considering different exposure times for three major parts of the facility including the processing area, office area and the accommodation module, the risk contours of CO, NO₂ and CH₄ over the entire facility are developed. The additivity characteristic of the risk-based approach was used to calculate the overall risk. The proposed approach helps to better design safety measures to minimize the impacts and effective emergency evacuation planning.     

北京市工业污染源大气污染物排放特征

北京市工业污染源大气污染物排放比较严重，其TSP，PM10，PM2．5，SO2，NOx和CO的排放量均占北京市固定污染源排放量的54％以上，煤烟型污染是工业污染的主要部分，占源污染物排放量比面源大，污染物排放主要集中在电力行业和冶金行业，污染源主要分布在城八区中的外四区，特别是工业比较集中的石景山地区和朝阳区，工业污染源排放的颗粒物中细颗粒物比例较高。     

光污染与城市建设

随着我国城市建设的不断发展,产生了一种新的城市环境污染光污染.由于对其缺乏足够的重视和研究,光污染问题日益严重.指出了光污染产生的原因和光污染的定义及分类,从对人、交通安全、生态环境、天文观测和能源利用5个方面分析了光污染的危害,最后从城市建设的角度,提出了光污染的防治措施.     

Risk assessment in a hypothetical network pipeline in UK transporting carbon dioxide

With the advent of Carbon Capture and Storage technology (CCS) the scale and extent of its handling is set to increase. Carbon dioxide (CO₂) capture plants are expected to be situated near to power plants and other large industrial sources. Afterward CO₂ is to be transported to storage site using one or a combination of transport media: truck, train, ship or pipeline. Transport by pipeline is considered the preferred option for large quantities of CO₂ over long distances. The hazard connected with this kind of transportation can be considered an emerging risk and is the subject of this paper.The paper describes the Quantitative Risk Assessment of a hypothetical network pipeline located in UK, in particular the study of consequences due to a CO₂ release from pipeline.The risk analysis highlighted that some sections of pipeline network cross densely populated areas. For this reason, some changes in the original path of the network have been proposed in order to achieve a significant reduction in the societal risk.     

Evaluation of thermal properties and process hazard of three ionic liquids through thermodynamic calculations and equilibrium methods

Industrial and new energy applications of ionic liquids (ILs) may have to be used at high temperatures conditions, such as in batteries and fuel applications, which may cause thermal hazards. However, there are few studies on the thermal hazards of ILs. To ensure the thermal safety of ILs processes, three commonly used ILs were selected for analysis: 1-butyl-3-methylimidazolium nitrate ([Bmim]NO₃), 1-butyl-2,3-dimethylimidazolium nitrate ([Bmmim]NO₃), and 1,3-dimethylimidazolium nitrate ([Mmim]NO₃). The process hazards under adiabatic conditions demonstrated that [Bmmim]NO₃ and [Mmim]NO₃ have extensive explosion hazards. The self-reaction characteristics determined by the isothermal test indicated that the ILs are nth reactions, and the thermal decomposition features were also determined by thermogravimetric analysis. The data were obtained with a nonlinear thermodynamic model and used to establish the basic thermal hazards of the three ILs. In addition, based on the thermal equilibrium theory, the critical safety parameters can be inferred. The effects of heat transfer in 25.0 g and 50.0 g containers were discussed. The results show that [Mmim]NO₃ will produce a thermal runaway reaction at a lower temperature (<100 °C) and has the shortest reaction time (<1 day), which means [Mmim]NO₃ is considered to be the most hazardous material among the three ILs studied.     

Older Adults at Increased Risk as Pedestrians in Victoria,Australia: An Examination of Crash Characteristics and Injury Outcomes

Objectives: Engaging in active transport modes (especially walking) is a healthy and environmentally friendly alternative to driving and may be particularly beneficial for older adults. However, older adults are a vulnerable group: they are at higher risk of injury compared with younger adults, mainly due to frailty and may be at increased risk of collision due to the effects of age on sensory, cognitive, and motor abilities. Moreover, our population is aging, and there is a trend for the current cohort of older adults to maintain mobility later in life compared with previous cohorts. Though these trends have serious implications for transport policy and safety, little is known about the contributing factors and injury outcomes of pedestrian collision. Further, previous research generally considers the older population as a homogeneous group and rarely considers the increased risks associated with continued ageing.

Method: Collision characteristics and injury outcomes for 2 subgroups of older pedestrians (65–74 years and 75+ years) were examined by extracting data from the state police–reported crash dataset and hospital admission/emergency department presentation data over the 10-year period between 2003 and 2012. Variables identified for analysis included pedestrian characteristics (age, gender, activity, etc.), crash location and type, injury characteristics and severity, and duration of hospital stay. A spatial analysis of crash locations was also undertaken to identify collision clusters and the contribution of environmental features on collision and injury risk.

Results: Adults over 65 years were involved in 21% of all pedestrian collisions. A high fatality rate was found among older adults, particularly for those aged 75 years and older: this group had 3.2 deaths per 100,000 population, compared to a rate of 1.3 for 65- to 74-year-olds and 0.7 for adults below 65 years of age. Older pedestrian injuries were most likely to occur while crossing the carriageway; they were also more likely to be injured in parking lots, at driveway intersections, and on sidewalks compared to younger cohorts. Spatial analyses revealed older pedestrian crash clusters on arterial roads in urban shopping precincts. Significantly higher rates of hospital admissions were found for pedestrians over the age of 75 years and for abdominal, head, and neck injuries; conversely, older adults were underrepresented in emergency department presentations (mainly lower and upper extremity injuries), suggesting an increased severity associated with older pedestrian injuries. Average length of hospital stay also increased with increasing age.

Conclusion: This analysis revealed age differences in collision risk and injury outcomes among older adults and that aggregate analysis of older pedestrians can distort the significance of risk factors associated with older pedestrian injuries. These findings have implications that extend to the development of engineering, behavioral, and enforcement countermeasures to address the problems faced by the oldest pedestrians and reduce collision risk and improve injury outcomes.     

Injury Severity Score alone predicts mortality when compared to EMS scene time and transport time for motor vehicle trauma patients who arrive alive to hospital

ABSTRACT

Objective: This study aims to identify the association, if any, between prehospital scene time, prehospital transport time, and Injury Severity Score (ISS) with in-hospital mortality.

Methods: A retrospective analysis was performed on patients at least 18 years of age who arrived to the hospital alive via emergency medical services (EMS) after a motor vehicle collision (MVC) between 1992 and 2016. These patients were divided into groups based on minutes spent at the scene and in transport. The ISS of the in-hospital mortalities, as well as the entire patient sample for each time frame, was collected. Patients without documented scene time, transport time, or ISS were excluded.

Results: Four thousand one hundred ninety-four patients were captured when analyzing scene time, though only 3,980 met inclusion criteria. In addition, 4,177 patients were captured when analyzing transport time, though only 3,979 met inclusion criteria. Scene time and transport time were not statistically significant predictors of in-hospital mortality (P = .31 and P = .458, respectively). ISS was found to be a statistically significant predictor of in-hospital mortality (P < .001).

Conclusions: ISS predicts mortality independent of scene time or transport time for patients who arrive to the hospital alive following an MVC at Guthrie Robert Packer Hospital. Limitations of our study include inability to capture prehospital deaths and inability to correlate ISS with prehospital injury severity scores.     

Corrosion behavior of steels for CO2 injection

The process chain for Carbon Capture and Sequestration (CCS) includes tubing for injection of CO₂ into saline aquifers. The compressed CO₂ is likely to contain specific impurities; small concentrations of SO₂ and NO₂ in combination with oxygen and humidity are most harmful. In addition, CO₂ saturated brine is supposed to rise in the well when the injection process is interrupted. The material selection has to ensure that neither CO₂ nor brine or a combination of both will leak out of the inner tubing. In this comprehensive paper the investigated materials range from low-alloy steels and 13% Cr steels up to high-alloy materials. Electrochemical tests as well as long term exposure tests were performed in CO₂, in brine and combination of both; pressure was up to 100 bar, temperature up to 60 °C. Whereas the CO₂ stream itself can be handled using low alloy steels, combinations of CO₂ and brine require more resistant materials to control the strong tendency to pitting corrosion. The corrosion behavior of heat-treated steels depends on factors such as microstructure and carbon content. For different sections of the injection tube, appropriate materials should be used to guarantee safety and consider cost effectiveness.     

基于灰色关联分析理论的典型区域土壤重金属污染评价研究

选择包头作为研究区,实地调研获得221个土壤试样,利用原子荧光光谱法和等离子体质谱法测试得到样品中8种重金属质量比。利用灰色关联分析,建立土壤中As、Cd、Cr、Cu、Hg、Ni、Pb、Zn与污染等级的关联度,结合Kriging空间插值方法对土壤污染等级的空间分布进行研究。统计结果表明,研究区主要为Pb和Zn污染。根据统计量所反映出的地区差异性,构建评价对象的因子集、评价因子等级标准,建立灰色关联土壤环境质量评价模型。并且利用Kriging插值将评价结果绘制成包头土壤环境污染等级专题图。研究表明:包头土壤环境呈现沿昆都仑河被污染的条带特点;市区郊区有Hg、Pb、Zn的点源污染。利用Kriging插值的线性无偏最优估计,可以得到研究区域的土壤污染评价专题图。实例验证了根据灰色关联分析建立的土壤重金属污染评价模型,能够充分利用污染数据的统计特性,克服内梅罗综合污染指数评价突显算术平均值与最大值的不合理性,通过对各污染属性的相对最优灰关联度进行排序,能够增强模型对灰关联度的分辨能力,更加客观地确定重金属在土壤污染等级评定中的权重,符合实际情况。     

Failure of a heat exchanger generated by an excess of SO2 and H2S in the Sulfur Recovery Unit of a petroleum refinery

The aim of this work is to investigate the level of damage to the heat exchanger in a Sulfur Recovery Unit (SRU) of a petroleum refinery. The by-products of oil refining are submitted to special treatment in order to meet technical specifications of corrosivity, sulfur content, acidity, formation of pollutant compounds, and color alteration. Sulfur is removed from the by-products in the form of H₂S, which is an acid gas that is sent to the SRU for sulfur production. The gases in the SRU are H₂S, CO₂, SO₂, and SO₃, which are corrosive to the mild steel equipment. The Unit is frequently forced to paralyze its activities due to the corrosion of its heat exchangers and pressure vessels, and the acid gas load is burnt causing the release of SO_x into the atmosphere. The above occurs when generalized corrosion damages SRU equipment. The importance of this work is to emphasize that the leakage of acid gas and sulfur into the atmosphere is a direct result of corrosion, which causes economical and environmental damage. This study may be used to improve the control of The Claus Process and to minimize corrosion damage. The SRU does not, at present, carry out any corrosion prevention methods. The corrosion of mild steel is controlled by correct air admission to oxide H₂S, and to produce SO₂, which is the reagent in the reaction of sulfur production.     

An explosion of a tank car carrying waste hydrogen peroxide

On the Metropolitan Expressway in Tokyo, a tank car exploded because it was carrying hydrogen peroxide (H₂O₂) in a compartment in which copper chloride (CuCl₂) remained. Although the main cause of the accident was trivial, the background on the accident suggested that an induction period in the reaction led to a mistake. This report describes the experimental investigation of the catalytic ability of CuCl₂, and comparing it with two other copper(II) compounds (nitrate: Cu(NO₃)₂; and copper sulfate: CuSO₄) and three iron(III) compounds (chloride: FeCl₃; nitrate: Fe(NO₃)₃; and sulfate: Fe₂(SO₄)₃).The experiments were performed using a reaction calorimeter. During the experiments at 35 °C, 2×10⁻⁵ mol of copper compounds slowly reacted with H₂O₂ and generated a precipitate. The iron compounds allowed the hydrogen peroxide to violently decompose. A 1×10⁻⁴ mol solution of CuCl₂, however, produced a violent decomposition at 35 °C. At 15 °C, a moderate heat release occurred.Based on these results, the concentration and temperature dependence of the catalytic ability of CuCl₂ were postulated to contribute to the induction period observed in the accident.