Ion exchange membrane-assisted electro-activation of aqueous solutions: Effect of the operating parameters on solutions properties and system electric resistance

The properties of electro-activated (EA) aqueous solutions as well as the dynamics of their changes were considered in the current study using aqueous solutions of NaCl and NaHCO₃. The concentrations of the salt solutions were 0.5, 0.25, 0.125 and 0.05 M. The tests were performed at the DC current densities of 25, 37.5, and 50 Å/m². The electro-activation reactor consisted of three individual cells assembled together and separated by anion-exchange (AEM) and cation-exchange (CEM) membranes. During the experiments, four configurations of the membrane placements and solutions concentrations were studied. The obtained results showed the dynamics of the electro-activation process that allows obtaining electro-activated solutions with targeted properties such as pH and oxydo-reduction potential (ORP). It was possible to obtain electro-activated solutions at the anodic side (acid anolyte) with pH of 3.0, 3.5, and 4.0 and ORP of +1100 ± 15 mV when NaCl solution was used as electrolyte. Furthermore, several types of electro-activated solutions with high redox potential (ORP = +921 ± 12 mV) and neutral pH (6.48 ± 0.05) were obtained on the anode side when sodium carbonate was used. At the same time, two types of solutions, one with acid pH (2.14 ± 0.14) and the other one with alkaline pH (10.46 ± 0.03) with ORP = +689 ± 10 and 110 ± 21 mV, respectively, were obtained in the central compartment which considered as electro-activated solutions obtained by means of noncontact electro-activation.     

对应分析在CFIT事故致因研究中的应用

为揭示可控飞行撞地(CFIT)事故致因规律,根据Reason-SHEL模型得出的10个CFIT事故致因因子,分析从飞行安全基金会数据库中整理出的2006—2011年间40起CFIT事故。在此基础上建立CFIT事故年份-成因列联表,再利用SPSS软件对表格进行对应分析。将事故成因和年份同时反映在二维散点图中,实现数据可视化。最后对图形进行向量、圆心接近点以及区域化等3项分析。根据结果得出,CFIT事故的主成因是人因操作和外界环境;随着年份增加,飞行员状态(药物/疲劳、经验不足)对造成CFIT事故的重要性越来越明显;不同年份有不同的重要致因因子。     

河北生态环境建设与京津协同发展障碍因素及思路建议

本文就河北生态环境建设与京津协同发展中障碍因素进行初步探讨,并提出破解障碍因素的具体思路建议。在对行政区划、产业发展、环境与发展的矛盾、市场化资源配置机制、环京津贫困带及环境属地管理模式六大障碍因素分析基础上,认为河北生态环境建设与京津协同发展,要站在京津冀协同发展战略高度,在京津冀协同发展框架下统筹规划,确立以市场为纽带的新型合作关系,实现区域内各方的密切配合、通力合作。以此为理念,提出破解河北生态环境建设与京津协同发展障碍因素的几点思路建议。     

固定污染源烟气比对监测的几点思考

固定源烟气对比监测是保证自动监测数据质量的重要手段。但是,有效性审核比对监测过程中存在烟气排放连续监测系统安装不规范、手工监测抗干扰能力较差、烟气预处理效果不稳定及监测点位差异影响监测结果比对等问题。在此基础上,提出了严格规范环境监测点位的布置,针对不同的污染源确定适合的监测技术方法,研发完善的烟气预处理设施以及建立健全的自动监测质量保证体系等解决问题的对策。     

耦合发酵产氢尾液处理的微生物电化学系统研究

区别于传统的稀释或加缓冲剂调节pH值的方法,本文提出采用微生物电解池（MEC）电调控暗发酵尾液pH值,并进一步采用微生物电合成系统（MES）降解废液产甲烷.结果表明,在MEC处理产氢暗发酵尾液过程中,伴随着阴极侧氢气的产生,暗发酵尾液中大量H⁺被消耗,溶液pH值从4.5升高到8.7;随后在MES中,产氢发酵尾液中有机物被进一步降解产生甲烷,其平均产甲烷速率达到4.5mmol/（L·d）,且在21d内化学需氧量（COD）去除率达到89%,远优于没有经过pH调控的产氢发酵尾液MES中的产甲烷性能.     

液体推进剂职业中毒风险评价及防护对策研究

本文以某发射场为例,通过主要危险源辨识、作业单元划分、现场调查和监测统计,利用风险指数评估法对液体推进剂职业中毒风险进行量化评价,结果表明:液体推进剂作业存在极度和高度职业中毒风险,发射场液体推进剂作业职业中度风险主要来源于液体推进剂及氮气;液体推进剂设备维修、应急救援及进罐作业存在极度职业中毒风险,转注/加注、取样为高度风险,化验及"三废"处理属于中度风险。根据评价结果并借鉴以往事故经验教训,指出职业中毒伤害与工程控制、个体防护措施和安全意识密切相关,不使用或不能正确使用呼吸防护装备是引发职业中毒的主要原因,并提出针对性的防护措施建议。     

Concentration Evolution of Gas Species within a Collapsing Bubble in a Liquid Medium

In this study numerical methods are used to investigate the relationship between chemical concentration of gas species within a cavitating bubble, equilibrium radius of the gas bubble and pressure variations in the ambient liquid. For this purpose, governing equations are developed to describe the dynamic equilibrium of a bubble in a flowing fluid and mass transfer between gas and liquid phases, where it was assumed that gases undergo isothermal compression, obey the ideal gas law, Henry law. It is further assumed that the concentration of each phase within the bubble is uniform. The resulting nonlinear equations are solved using implicit Trapezoidal method with Newton iteration. Four gas species are modeled under various initial and ambient pressure variation conditions. These conditions maybe considered to represent typical cavitation events. The numerical results obtained are presented in terms of dimensionless numbers. These results indicate that chemical damage maybe an important component of cavitation surface damage, since high concentration profiles may develop within a collapsing bubble. Proposed formulation and numerical solutions are simple and cost effective to implement. The results presented in this study maybe used to benchmark experimental investigations or other more complex solutions, which are outside the scope of this study.     

Implementation of the ecosystem services approach in Swedish municipal planning

While ecosystem-based planning approaches are increasingly promoted through international and national policies, municipalities are still struggling with translating them into practice. Against this background, this paper aims to increase the knowledge of current advances and possible ways to support the implementation of the ecosystem services (ES) approach at the municipal level. More specifically, we analyze how ES have been integrated into comprehensive planning within the municipality of Malmö in Sweden over the last 60 years, a declared forerunner in local environmental governance. Based on a content analysis of comprehensive plans over the period 1956–2014 and interviews with municipal stakeholders, this paper demonstrates how planning has shifted over time toward a more holistic view of ES and their significance for human well-being and urban sustainability. Both explicit and implicit applications of the ES concept were found in the analyzed comprehensive plans and associated programs and projects. Our study shows how these applications reflect international, national, and local policy changes, and indicates how municipalities can gradually integrate the ES approach into comprehensive planning and facilitate the transition from implicit to more explicit knowledge use.     

对硝基苯胺的光化学降解研究

系统研究了氙灯和高压汞灯照射下对硝基苯胺(PNA)在蒸馏水、人工海水和天然海水中的光化学降解情况.结果表明,PNA光降解速率会受到光源、溶液介质、温度、起始浓度、重金属离子、甲醇及过氧化氢浓度的影响.随着光源强度的增强、起始浓度的增大、温度的增高和过氧化氢量的增加,PNA在海水中光降解速率相应加快;然而甲醇的加入可有效...     

饮食业油烟监测中存在的问题及解决对策

从实际的饮食业油烟监测出发,结合执行与实践《饮食业油烟排放标准》(GB18483-2001)过程中的各种体会,从采样位置、采样工况以及基准灶头数这三个方面,对饮食业油烟监测中存在的问题进行了探讨,并提出了相应的解决对策:油烟监测前,应确保采样位置的规范,必须对采样断面和位置进行优化选择;油烟监测中,应确保采样工况的正常,油烟净化设备务必处于正常工作状态,要派专人负责工况的监督,维持工况的稳定;在今后的标准修订中,建议对基准灶头数的折算方式予以明确,而不是目前按灶的总发热功率或排气罩灶面总投影面积两种方式并存。