HRT对CO2-MBfR去除高SO42-废水中NO3--N的影响

针对含NO₃^--N与较高浓度SO₄^2-实际工业废水处理较难的问题,考察了不同水力停留时间（HRT）下连续运行的CO₂-氢基质膜生物膜反应器（CO₂-MBfR）处理模拟废水和实际工业废水的性能,结果表明,2种废水的出水NO₃^--N浓度均随着HRT的减小而增大,模拟废水中NO₃^--N的处理效果和电子通量分配比例均优于实际废水,但其电子通量分配的格局基本不变：NO₃^--N和SO₄^2-的电子通量分别在90.09%~97.49%和2.51%~9.91%左右.要实现实际废水总氮达到15mg/L的排放标准,需维持HRT不少于10.4h.     

A case study of development and application of a streamlined control and response modeling system for PM2.5 attainment assessment in China

This article describes the development and application of a streamlined air control and response modeling system with a novel response surface modeling-linear coupled fitting method and a new module to provide streamlined model data for PM_(2.5) attainment assessment in China.This method is capable of significantly reducing the dimensions required to establish a response surface model,as well as capturing more realistic response of PM_(2.5) to emission changes with a limited number of model simulations.The newly developed module establishes a data link between the system and the Software for Model Attainment Test—Community Edition(SMAT-CE),and has the ability to rapidly provide model responses to emission control scenarios for SMAT-CE using a simple interface.The performance of this streamlined system is demonstrated through a case study of the Yangtze River Delta(YRD) in China.Our results show that this system is capable of reproducing the Community Multi-Scale Air Quality(CMAQ) model simulation results with maximum mean normalized error 3.5%.It is also demonstrated that primary emissions make a major contribution to ambient levels of PM_(2.5) in January and August(e.g.,more than50%contributed by primary emissions in Shanghai),and Shanghai needs to have regional emission control both locally and in its neighboring provinces to meet China's annual PM_(2.5)National Ambient Air Quality Standard.The streamlined system provides a real-time control/response assessment to identify the contributions of major emission sources to ambient PM_(2.5)(and potentially O_3 as well) and streamline air quality data for SMAT-CE to perform attainment assessments.     

Practical Perspectives of 1,4‐Dioxane Investigation and Remediation

1,4‐Dioxane (dioxane) is a contaminant of emerging concern that is classified by the U.S. Environmental Protection Agency as a likely human carcinogen. Dioxane has been used as a minor or major ingredient in many applications, and is also generated as an unwanted by‐product of industrial processes associated with the manufacturing of polyethylene, nonionic surfactants, and many consumer products (cosmetics, laundry detergents, shampoos, etc.). Dioxane is also a known stabilizer of chlorinated solvents, particularly 1,1,1‐trichloroethane, and has been commonly found comingled with chlorinated solvent plumes. Dioxane plumes at chlorinated solvent sites can complicate site closure strategies, which to date have not typically focused on dioxane. Aggressive treatment technologies have greatly advanced and are clearly capable of achieving lower parts per billion cleanup criteria using ex situ advanced oxidation processes and sorption media. In situ chemical oxidation has also been demonstrated to effectively remediate dioxane and chlorinated solvents. Other in situ remedies, such as enhanced bioremediation, phytoremediation, and monitored natural attenuation, have been studied; however, their ability to achieve cleanup levels is still somewhat questionable and is limited by co‐occurring contaminants. This article summarizes and provides practical perspectives on dioxane analysis, plume stability relative to other contaminants, and the development of investigation tools and treatment technologies.     

Design and modeling of optimal distillation sequence for recovery of valuable components from a waste photoresist stripper

Currently, waste photoresist stripper from the semiconductor industries is generally incinerated at high temperatures or processed as a high-calorie fuel, which can have adverse effects on the environment and economy. Recovery of valuable solvents from waste photoresist strippers is, therefore, very important for thin flat transistor-liquid crystal display (TFT-LCD) manufactures to reduce the production costs and protect the environment against industrial waste. In the present work, systematic laboratory-scale distillation experiments were carried out to regenerate the organic solvents from the waste photoresist stripper and determine if they are feasible to recycle for commercial TFT-LCD grade chemicals: in particular, 1-hydroxyethylpiperazine and methyl diglycol were mainly tried to retrieve. Based on the experiment results, possible alternative distillation sequences were examined through intensive techno-economic analysis using a rigorous process simulator. As a result, an optimal distillation sequence and condition were drawn to separate valuable organic solvents from waste photoresist stripper for a commercial purpose recovery process.     

混合多目标遗传算法求解地下水污染修复管理模型

为了提高多目标遗传算法Pareto解的局部最优性,本文将快速非支配遗传算法(NSGAII)与一种迭代式的局部搜索算法(Hill Climber with Step,HCS)相结合,开发了一种新的混合多目标遗传算法NSGAII-HCS.利用CONV1和ZDT6两个经典的多目标优化函数对NSGAII-HCS的性能进行测试,与传统的多目标算法NSGAII相比,CONV1得到的Pareto锋面与真实Pareto最优解锋面的平均距离由5.49减小到1.74,ZDT6则由0.16减小到0,表明NSGAII-HCS在保证解多样性的前提下,能使解接近或收敛到真实的Pareto最优解锋面.最后,将NSGAII-HCS与地下水流模拟软件MODFLOW和溶质运移模拟软件MT3DMS相耦合,并应用到一个理想的二维地下水污染修复管理模型中,结果分析表明该方法可为地下水污染治理提供多样的和收敛的Pareto管理策略,是一种稳定可靠的多目标优化方法.     

New insight into adsorption characteristics and mechanisms of the biosorbent from waste activated sludge for heavy metals

The adsorption characteristics and mechanisms of the biosorbent from waste activated sludge were investigated by adsorbing Pb2+and Zn2+in aqueous single-metal solutions. A p H value of the metal solutions at 6.0 was beneficial to the high adsorption quantity of the biosorbent. The optimal mass ratio of the biosorbent to metal ions was found to be 2. A higher adsorption quantity of the biosorbent was achieved by keeping the reaction temperature below 55°C. Response surface methodology was applied to optimize the biosorption processes, and the developed mathematical equations showed high determination coefficients(above 0.99 for both metal ions) and insignificant lack of fit(p = 0.0838 and 0.0782 for Pb2+and Zn2+, respectively). Atomic force microscopy analyses suggested that the metal elements were adsorbed onto the biosorbent surface via electrostatic interaction. X-ray photoelectron spectroscopy analyses indicated the presence of complexation(between –NH2,-CN and metal ions) and ion-exchange(between –COOH and metal ions). The adsorption mechanisms could be the combined action of electrostatic interaction, complexation and ion-exchange between functional groups and metal ions.     

Are there higher pedestrian fatalities in larger cities?: A scaling analysis of 115 to 161 largest cities in the United States

Objective: In 2012, 4,743 pedestrians were killed in the United States, representing 14% of total traffic fatalities. The number of pedestrians injured was higher at 76,000. Therefore, 36 out of 52 of the largest cities in the United States have adopted a citywide target of reducing pedestrian fatalities. The number of cities adopting the reduction goal during 2011 and 2012 increased rapidly with 8 more cities. We examined the scaling relationship of pedestrian fatality counts as a function of the population size of 115 to 161 large U.S. cities during the period of 1994 to 2011. We also examined the scaling relationship of nonpedestrian and total traffic fatality counts as a function of the population size.

Methods: For the data source of fatality measures we used Traffic Safety Facts Fatality Analysis Reporting System/General Estimates System annual reports published each year from 1994 to 2011 by the NHTSA. Using the data source we conducted both annual cross-sectional and panel data bivariate and multivariate regression models. In the construction of the estimated functional relationship between traffic fatality measures and various factors, we used the simple power function for urban scaling used by Bettencourt et al. (2007 Bettencourt LMA, Lobo J, Helbing D, Kühnert C, West GB. Growth, innovation, scaling and the pace of life in cities. Proc Natl Acad Sci USA. 2007;104:7301–7306.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar], 2010 Bettencourt LMA, Lobo J, Strumsky D, West GB. Urban scaling and its deviations: revealing the structure of wealth, innovation and crime across cities. PLoS ONE. 2010;5:e13541.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and the refined STIRPAT (stochastic impacts by regression on population, affluence, and technology) model used in Dietz and Rosa (1994 Dietz T, Rosa EA. Rethinking the environmental impacts of population, affluence and technology. Human Ecology Review. 1994;1:277–300. [Google Scholar], 1997 Dietz T, Rosa EA. Effects of population and affluence on CO₂ emissions. Proc Natl Acad Sci USA. 1997;94:175–179.[Crossref], [PubMed], [Web of Science ®] , [Google Scholar]) and York et al. (2003 York R, Rosa EA, Dietz T. STIRPAT, IPAT and IMPACT: analytic tools for unpacking the driving forces of environmental impacts. Ecol Econ. 2003;46:351–365.[Crossref], [Web of Science ®] , [Google Scholar]).

Results: We found that the scaling relationship display diseconomies of scale or sublinear for pedestrian fatalities. However, the relationship displays a superlinear relationship in case of nonpedestrian fatalities. The scaling relationship for total traffic fatality counts display a nearly linear pattern. When the relationship was examined by the 4 subgroups of cities with different population sizes, the most pronounced sublinear scaling relationships for all 3 types of fatality counts was discovered for the subgroup of megacities with a population of more than 1 million.

Conclusions: The scaling patterns of traffic fatalities of subgroups of cities depend on population sizes of the cities in subgroups. In particular, 9 megacities with populations of more than 1 million are significantly different from the remaining cities and should be viewed as a totally separate group. Thus, analysis of the patterns of traffic fatalities needs to be conducted within the group of megacities separately from the other cities with smaller population sizes for devising prevention policies to reduce traffic fatalities in both megacities and smaller cities.     

Reducing the risk of rear-end collisions with infrastructure-to-vehicle (I2V) integration of variable speed limit control and adaptive cruise control system

Objective: Adaptive cruise control (ACC) has been investigated recently to explore ways to increase traffic capacity, stabilize traffic flow, and improve traffic safety. However, researchers seldom have studied the integration of ACC and roadside control methods such as the variable speed limit (VSL) to improve safety. The primary objective of this study was to develop an infrastructure-to-vehicle (I2V) integrated system that incorporated both ACC and VSL to reduce rear-end collision risks on freeways.

Methods: The intelligent driver model was firstly modified to simulate ACC behavior and then the VSL strategy used in this article was introduced. Next, the I2V system was proposed to integrate the 2 advanced techniques, ACC and VSL. Four scenarios of no control, VSL only, ACC only, and the I2V system were tested in simulation experiments. Time exposed time to collision (TET) and time integrated time to collision (TIT), 2 surrogate safety measures derived from time to collision (TTC), were used to evaluate safety issues associated with rear-end collisions. The total travel times of each scenario were also compared.

Results: The simulation results indicated that both the VSL-only and ACC-only methods had a positive impact on reducing the TET and TIT values (reduced by 53.0 and 58.6% and 59.0 and 65.3%, respectively). The I2V system combined the advantages of both ACC and VSL to achieve the most safety benefits (reduced by 71.5 and 77.3%, respectively). Sensitivity analysis of the TTC threshold also showed that the I2V system obtained the largest safety benefits with all of the TTC threshold values. The impact of different market penetration rates of ACC vehicles in I2V system indicated that safety benefits increase with an increase in ACC proportions.

Conclusions: Compared to VSL-only and ACC-only scenarios, this integrated I2V system is more effective in reducing rear-end collision risks. The findings of this study provide useful information for traffic agencies to implement novel techniques to improve safety on freeways.     

A New Perspective on Sustainable Soil Remediation—Case Study Suggests Novel Fungal Genera Could Facilitate in situ Biodegradation of Hazardous Contaminants

Deciding upon a cost effective and sustainable method to address soil pollution is a challenge for many remedial project managers. High pressure to quickly achieve cleanup goals pushes for energy‐intensive remedies that rapidly address the contaminants of concern with established technologies, often leaving little room for research and development especially for slower treatment technologies, such as bioremediation, for the more heavily polluted sites. In this case study, new genomic approaches have been leveraged to assess fungal biostimulation potential in soils polluted with particularly persistent hydrophobic contaminants. This new approach provides insights into the genetic functions available at a given site in a way never before possible. In particular, this article presents a case study where next‐generation sequencing has been used to categorize fungi in soils from the Atlantic Wood Industries Superfund site in Portsmouth, Virginia. Data suggest that original attempts to harness fungi for bioremediation may have focused on fungal genera poorly suited to survive under heavily polluted site conditions, and that more targeted approaches relying on native indigenous fungi which are better equipped to survive under site‐specific conditions may be more appropriate. ©2016 Wiley Periodicals, Inc.     

民用飞机机载设备振动试验要求和应用分析(一) DO 160F/G民用固定翼飞机机载设备振动试验要求

阐述了民用飞机机载设备振动环境的特点和振动试验分类,归纳和汇总了DO 160F/G中的各类民用飞机机载设备的振动试验要求,包括振动谱、振动量值和试验持续时间等,并进行了分析和说明,以便于查阅和使用。最后对民用飞机机载设备振动试验方法的应用进行了概括,介绍了民用固定翼飞机的机载设备振动试验要求,按设备在机上的区域不同进行分类,详细地对比说明各个位置上设备的振动试验要求;介绍了民用直升机的机载设备振动试验要求。