Meteorological mechanism for a large-scale persistent severe ozone pollution event over eastern China in 2017

An intensive and persistent regional ozone pollution event occurred over eastern China from 25 June to 5 July 2017.73 out of 96 selected cities,most located in the Beijing-TianjinHebei and the surrounding area(BTHS),suffered severe ozone pollution.A north-south contrast ozone distribution,with higher ozone(199±33 μg/m³) in the BTHS and lower ozone(118±25 μg/m³) in the Yangtze River Delta(YRD),was found to be dominated by the position of the West Pacific Subtropical High(WPS...     

毒气泄漏场景下基于蒙特卡罗的工厂布局研究

由于在工业生产中使用危险化学品会引起各种工业事故的发生,为了减小事故风险,降低由此产生的经济损失,必须将安全问题考虑在内,对工厂进行合理布局。采用蒙特卡罗模拟技术,研究某生产设施发生有毒气体泄漏的场景下,气象条件的不确定性对工厂布局的影响。以风向、风速及大气稳定性作为随机变量,通过扩散模型、概率函数和蒙特卡罗模拟得到中毒死亡概率。将上述随机方法应用在天津某个处于规划布局阶段的工厂内,以氨气泄漏为例,根据该地区常年风向分布及所得风险等值线图对工厂设施布局提出建议。案例分析表明:该工厂需要进行重新布局,应将受体设施布置在风险较小、风频较小的方位上;同时该随机方法能够为工厂布局提供决策支持。     

湿法脱硫系统设计无旁路相关问题的探讨

介绍国内电厂首次投运的无旁路脱硫系统,其具有无GGH、引风机和增压风机合并、"烟塔合一"的特点。通过与其他脱硫系统的比较,讨论了无旁路脱硫系统吸收塔、烟道、公用系统以及除尘器的设计和选型特点,总结了其易出现的问题及运行中的控制方法。根据调试经验,给出了无脱硫旁路系统的运行步序原则。     

落石冲击下多种类型土壤缓冲性能研究

针对现有研究对落石灾害中不同类型土壤中落石的最大冲击力和冲击力变化规律偏差较大的情况,对落石在四种土壤中的冲击力进行研究。通过试验验证SPH-FEM方法在冲击力方面的适用性。采用SPH-FEM模型分析落石在四种土壤中的最大冲击力、冲击力时程曲线规律和在砂土中的冲击力时程曲线公式。分析结果表明:SPH-FEM数值模型能够准确用于研究落石在土层中的最大冲击力和冲击力时程曲线。四种土壤的缓冲性能顺序为砂土、黏土、壤土和黄棕壤。研究得到落石在四种土壤中的最大冲击力与落体直径、冲击速度的关系曲线以及在砂土中的冲击力时程曲线公式。     

Effects of La3+, Ce3+ on nitrogen removal in sequencing batch reactor

Batch experiments were conducted to study the short-term biological effects of rare earth ions (La³⁺, Ce³⁺) and their mixture on the nitrogen removal in a sequencing batch reactor (SBR). The data showed that higher NH₄ ⁺-N removal rate, total inorganic nitrogen removal efficiency, and denitrification efficiency were achieved at lower concentrations of rare earth elements (REEs) (<1 mg/L). In the first hour of the aeration stage of SBR, the presence of REEs increased the total inorganic nitrogen removal efficiency and NH₄ ⁺-N removal efficiency by 15.7% and 10%–15%, respectively. When the concentrations of REEs were higher than 1 mg/L, the total inorganic nitrogen removal efficiency decreased, and nitrate was found to accumulate in the effluent. When the concentrations of REEs was up to 50.0 mg/L, the total inorganic nitrogen removal efficiency was less than 30% of the control efficiency with a high level of nitrate. Lower concentrations of REEs were found to accelerate the nitrogen conversion and removal in SBR.     

塔河县环境监测能力建设的必要性和可行性分析

文章从塔河县环境监测站现状出发,分析了塔河县环境监测能力建设的必要性和可行性,最后提出了塔河县环境监测站建设标准.     

Collaborative influence of morphology tuning and RE (La,Y, and Sm) doping on photocatalytic performance of nanoceria

Environmental Science and Pollution Research - Tuning morphology and doping additional rare earth (RE) cations are potential techniques to promote the photocatalytic performance of ceria (CeO2),...     

Global burden analysis and AutoGluon prediction of accidental carbon monoxide poisoning by Global Burden of Disease Study 2019

Environmental Science and Pollution Research - Accidental carbon monoxide poisoning (ACOP) is the most common occupational toxic disease, but related data are scarce or non-existent in many...     

Associations between exposure to different heavy metals and self-reported erectile dysfunction: a population-based study using data from the 2001-2004 National Health and Nutrition Examination Survey

Environmental Science and Pollution Research - Heavy metals are ubiquitous and nonbiodegradable pollutants that are widely distributed in the environment. Heavy metal exposure can damage various...     

Application of a combined response surface methodology (RSM)-artificial neural network (ANN) for multiple target optimization and prediction in a magnetic coagulation process for secondary effluent from municipal wastewater treatment plants

Environmental Science and Pollution Research - In this study, an enhanced coagulation-flocculant process incorporating magnetic powder was used to further treat the secondary effluent of domestic...