Ecotoxicological effects of Trichloroethene upon plankton

A case study in an experimental pond was performed to evaluate the ecotoxic effects of Trichloroethene (TRI) upon the population density and productivity of phyto‐ and zooplankton. TRI was continuously released into two pond enclosures over 11 weeks (mean concentrations 1.5 and 7.5 mg/l). The chronic chemical treatment showed distinctive toxic influences upon the biota. Following the high TRI concentration, the phytoplankton density slightly increased; the productivity per single cells, however, was significantly reduced compared to the controls and the low TRI concentration. Cryptophyceae were the most sensitive algae taxa. The density and reproductivity of Daphniae and Phyllopodae decreased by the high TRI concentration. Most of the Rotatoriae were not negatively influenced. With increasing TRI concentrations two different bacteria forms showed a mass development. Small amounts of Trichloroacetic acid were detected in both enclosures as a conversion product of TRI (～3 μg/l after 80 days treatment).     

Removal of nitrogen and phosphorus from textile wastewater by soilless culture of Lolium multiflorum

A technique of soilless culture for removal of total nitrogen (TN) and total phosphorus (TP) from textile wastewater using Lolium multiflorum was conducted in this research. The TN concentration decreased from 50.72 mg/L to 24.64–27.89 mg/L and TP decreased from 6.9 mg/L to 3.7–4.1 mg/L in the experimental tank with the size of 4.7 m x 1.2 m x 0.75 m. The results suggested that L. multiflorum could absorb a large amount of N and P elements from the wastewater. This technique of soilless culture has many advantages such as simple equipment, low cost, easy operation, low energy consumption, convenient management and flexible disposition.     

Post-seismic allocation of medical staff in the Longmen Shan fault area: case study of the Lushan Earthquake

In April 2013, a 7.0 magnitude earthquake struck along the Longmen Shan fault in the city of Ya'an, Sichuan province, China, causing 200 deaths, 11,470 injuries and 21 people to go missing. As no scientific disaster management studies have been done on medical staff dynamic behavior in the Longmen Shan fault area, this paper develops a system dynamics (SD) model to simulate the relief activities in the area after the 2008 Sichuan Earthquake shook Wenchuan County. Based on this SD model, the simulation showed that the results regarding the cumulative number of deaths and the final death toll fit the reality well for the 2008 Sichuan Earthquake in the Longmen Shan fault area. Findings from the simulation confirmed the best ratio of medical staff to rescue workers. After implementing the findings for the medical relief work at the 2013 Sichuan Lushan Earthquake, reasonable earthquake rescue policies were developed for the Longmen Shan fault area. The SD model demonstrated that it was possible to predict the optimum number of medical staff and that medical staff need to be trained to improve their treatment abilities. Furthermore, it is suggested that search and rescue workers should also assist in restoring road transport during any medical relief activities in the Longmen Shan fault area. These policies can be generalized to other earthquake relief activities in the Longmen Shan fault area as well as being a valuable reference for similar mountainous earthquake areas.     

苹果和土壤中丙森锌的消解动态及残留规律

研究了苹果和土壤中丙森锌残留的气相色谱分析方法,及其代谢物乙撑硫脲的高效液相色谱分析方法,并在天津、山东烟台和陕西咸阳进行了苹果和土壤中丙森锌及其代谢物乙撑硫脲残留消解动态和残留规律田间试验研究.结果表明,在0.05—2 mg.kg-1的加标水平下,苹果和土壤中丙森锌的加标回收率分别为77.12%—92.85%和9.24%—94.68%,变异系数分别为3.30%—6.56%和3.29%—5.29%;在0.05—1 mg.kg-1的加标水平下,苹果和土壤中乙撑硫脲的加标回收率分别为80.91%—97.47%和84.11%—99.97%,变异系数分别为3.23%—3.82%和2.80%—3.40%.苹果和土壤中丙森锌和乙撑硫脲的最小检出量分别为5.0×10-10g和1.0×10-10g,其中苹果和土壤中丙森锌的最低检出浓度为0.025 mg.kg-1,乙撑硫脲的最低检出浓度为0.005 mg.kg-1.按1.5倍推荐剂量600倍稀释液在苹果上施用65%戊唑醇.丙森锌可湿性粉剂1次,丙森锌在苹果和土壤中的残留消解半衰期分别为6.0—6.8 d和8.7—10.1 d.按推荐剂量和1.5倍推荐剂量在苹果上各施用65%戊唑醇.丙森锌可湿性粉剂3—4次,2次施药间隔为10 d,距最后一次施药21 d时,丙森锌在苹果中的最高残留量低于我国农业行业标准规定的最大残留限量2 mg.kg-1.     

系统动力学在空港区域规划环境影响评价中的应用

作为机场与城市间的过渡区,空港区域具有经济-社会-环境发展影响因素众多、变化快的特征.针对此,本文基于空港区域系统动力学模拟模型,结合类比法和情景分析法,用于空港区域不同发展方案的经济、社会、环境影响预测和评价.具体步骤包括:发展分析-影响识别-模型构建-零方案/规划方案模拟-替代方案设计-减缓措施,各步骤间动态反馈.对郑州航空港区进行案例研究,结果表明,相较于零方案,规划方案具有经济社会发展优、污染排放少的优点,但仍无法满足环境容量要求;设计了3种替代情景方案,据此提出产业结构优化、能源结构调整等减缓措施.     

水体沉积物中石油类物质释放过程动力学研究

模拟水体沉积物中石油类物质向水相中释放的动力学过程,探讨在不同石油污染强度下,石油物质在水相中饱和浓度的变化。研究结果表明:上述过程可以用滞膜模型进行描述,释放过程为典型的一级动力学过程,沉积物中石油含量与水相中石油的释放浓度呈正向关系,在相同的释放条件下,污染强度越高,水相中石油的饱和浓度越高,释放速度也越快。     

概率火灾安全分析方法研究

为分析和评估火灾对设备、建筑物等敏感目标结构安全的影响,结合化工定量风险评估方法和气体爆炸概率安全分析方法,提出概率火灾安全分析策略和实施流程。该方法包括火灾危害辨识、泄漏速率计算、火灾后果模拟、频率分析、绘制频率超越热载荷曲线、结构响应分析等关键步骤。以某柴油罐区为例,通过频率分析和火灾模拟,绘制出频率超越热载荷曲线,假定火灾风险可接受准则为10-4/a,求得对应的可信热载荷为21 kW/m2,并以此值作为结构热响应分析的输入参数。火灾概率安全分析方法侧重于描述火灾热辐射强度及其对应的发生可能性,判定敏感目标遭遇的可信火灾热载荷强度和结构热响应行为,评估消防减灾措施效果,确保结构完整性和可用性,不评价工艺系统潜在火灾风险的高低。     

层状节理岩体模型冲击实验

为研究层状节理岩体在冲击荷载作用下的力学特性,实验采用水泥砂浆预制层状节理岩体模型,设计4个落锤高度对不同节理组数的岩体进行冲击加载。通过对冲击过程中载荷及加速时程信号的分析处理,得出节理岩体动态承载力与节理组数呈负相关性,压缩位移与冲击高度呈正相关性;当冲击荷载较小时,节理岩体动态压缩位移主要来自节理法向闭合,节理周边开始产生细微裂缝;随着冲击荷载的逐渐增大,裂缝逐渐沿节理面扩展贯通导致岩体破坏。     

Study of chemical supply system of high-tech process using inherently safer design strategies in Taiwan

The photoelectric, semiconductor and other high-tech industries are Taiwan's most important economic activities. High-tech plant incidents are caused by hazardous energy, even when that energy is confined to the inside of the process machine. During daily maintenance procedures, overhauling or troubleshooting, engineers entering the interior of the machines are in direct contact with the source of the energy or hazardous substances, which can cause serious injury. The best method for preventing such incidents is to use inherently safer design strategies (ISDs); this approach can fully eliminate the dangers from the sources of hazardous energy at a facility.This study first conducts a lithography process hazard analysis and compiles a statistical analysis of the causes of the fires and losses at high-tech plants in Taiwan since 1996, the aim being to establish the necessary improvement measures by using the Fire Dynamics Simulation (FDS) to solve relevant problems. The researchers also investigate the lithography process machine in order to explore carriage improvement measures, and analyse the fires' causes and reactive materials hazardous properties, from 1996 to 2012. The effective improvement measures are established based on the accident statistics. The study site is a 300 mm wafer fabrication plant located in Hsinchu Science Park, Taiwan.After the completion of the annual maintenance jobs improvement from September 2011 to December 2012, the number of lithography process accidents was reduced from 6 to 1. The accident rate was significantly reduced and there were no staff time losses for a continuous 6882 h. It is confirmed that the plant safety level has been effectively enhanced. The researchers offer safety design recommendations regarding transport process appliances, chemical storage tanks, fume cupboard devices, chemical rooms, pumping equipment, transportation pipelines, valve manual box (VMB) process machines and liquid waste discharge lines. These recommendations can be applied in these industries to enhance the safety level of high-tech plants, facilities or process systems.     

零价纳米铁吸附去除水中六价铬的研究

利用液相还原法制备的零价纳米铁(nZVI)进行了去除水中Cr(Ⅵ)的实验研究.结果表明,nZVI对Cr的去除效果明显优于还原铁粉和粉末活性碳;pH值越小、初始Cr浓度越低、nZVI放置时间越短及投加量越大均有利于水中Cr(Ⅵ)的去除,最佳去除率近100%;反应动力学拟合结果表明,nZVI去除六价铬符合准二级动力学模型;反应后nZVI颗粒的扫描电镜及电子能谱结果显示Cr占12.02%(wt),结合对反应溶液中Cr(Ⅵ)和Cr(Ⅲ)分析,说明吸附、还原与共沉淀可能是nZVI去除水中六价铬的主要机理.