LNG accident dynamic simulation: Application for hazardous consequence reduction

The evaluation of exclusion (hazard) zones around the LNG stations is essential for risk assessment in LNG industry. In this study, computational fluid dynamics (CFD) simulations have been conducted for the two potential hazards, LNG flammable vapor dispersion and LNG pool fire radiation, respectively, to evaluate the exclusion zones. The spatial and temporal distribution of hazard in complex spill scenario has been taken into account in the CFD model. Experimental data from Falcon and Montoir field tests have been used to validate the simulation results. With the valid CFD model, the mitigation of the vapor dispersion with spray water curtains and the pool fire with high expansion foam were investigated. The spray water curtains were studied as a shield to prevent LNG vapor dispersing, and two types of water spray curtain, flat and cone, were analyzed to show their performance for reduction and minimization of the hazard influencing distance and area. The high expansion foam firefighting process was studied with dynamic simulation of the foam action, and the characteristics of the foam action on the reduction of LNG vaporization rate, vapor cloud and flame size as well as the thermal radiation hazard were analyzed and discussed.     

Noise Control Strategies for Occupational Safety and Better Working Environments

Hearing impairment in humans due to occupational noise exposure is one of the significant occupational diseases in many countries. The equipment to measure noise levels and daily noise exposure in existing noisy environments is readily available and can be used to assess the risk of hearing damage. This article examines the currently legislated hearing damage risk criterion and compares the two main noise level-time trade-off schemes being used. The engineering methods for controlling excessive noise levels and techniques to either bring them below the hearing damage risk threshold or to within an acceptable range for the workplace requirement are discussed, together with the expected improvements by such measures.     

利用水蚯蚓进行污泥减量的研究

常规的污泥处理需要花费大量的人力和物力,且处置不当极易对环境造成二次污染.利用微型生物的捕食作用进行污泥减量,清洁无污染,是一项实现污泥源头治理的绿色技术.利用水蚯蚓原位消解污泥技术对成都市凤凰河二沟污水处理厂配水池污泥进行消解实验,通过实验监测来分析污泥减量情况以及对水质的影响.结果表明改造后的工艺污泥减量效果明显,每年可消解污泥240.9t,污泥的沉降性能变好,MLVSS/MLSS降低至35.3％,且出水COD降解率一般为30％,为后续工艺减少负荷.     

江苏省畜禽养殖污染减排措施与政策研究

为提高江苏省畜禽养殖污染治理水平,达到污染减排要求,完成污染减排任务,本文从分析江苏省畜禽养殖业污染产生量、排放量和污染特征入手,对污染治理措施和法律、法规及政策支撑等进行了归纳总结,深入分析了目前治理中存在的主要问题,提出了适合江苏畜禽养殖污染治理的技术模式,以及促进污染减排目标实现的管理机制和保障条件。     

验证污染物减排成效方法研究

验证污染减排成效,创建污染物排放量、浓度与环境质量的相关性,分析污染物减排与环境质量之间复杂的交互关系,研究二者之间的作用响应机制;引入定义减排率与浓度降低率,创建相关性,更能真实反映减排成效。对加强环境管理、削减污染物排放、治理污染、调整产业结构、制定环境保护政策具有现实和重要的指导作用。     

轿车前制动噪声降噪方案研究

本文针对轿车出现的前制动噪声问题进行了研究和改进,以及采取改进方案后是否会对制动性能造成影响进行了系统的阐述。     

气田增压机组烟气余热利用技术

综述国内外烟气余热利用技术的研究及应用现状,主要包括热能直接回收、吸收式制冷、有机朗肯循环和温差发电等方式。结合气田开采实际,分析讨论各类余热利用技术在气田增压机组烟气余热利用中的应用潜力和发展方向。在选择余热利用方案时,应结合气田增压机组现有条件、机组性能以及运行模式等因素进行综合评估。     

光催化还原法处理含cr（Ⅵ）废水的研究

采用自制TiO2作为光催化剂,利用光催化-混凝联合处理含Cr（Ⅵ）废水,研究了废水的pH值、催化剂用量、反应时间、有机物和混凝剂种类对含Cr（Ⅵ）废水中Cr（Ⅵ）去除率的影响。结果表明,在添加EDTA,pH值为1,紫外灯120min左右,二氧化钛加入量为0．4g,采用FeCl3和PAM作为混凝剂时,Cr（Ⅵ）的去除效率最好。     

One-dimensional model for biogeochemical interactions and permeability reduction in soils during leachate permeation

This paper uses the findings from a column study to develop a reactive model for exploring the interactions occurring in leachate-contaminated soils. The changes occurring in the concentrations of acetic acid, sulphate, suspended and attached biomass, Fe(II), Mn(II), calcium, carbonate ions, and pH in the column are assessed. The mathematical model considers geochemical equilibrium, kinetic biodegradation, precipitation-dissolution reactions, bacterial and substrate transport, and permeability reduction arising from bacterial growth and gas production. A two-step sequential operator splitting method is used to solve the coupled transport and biogeochemical reaction equations. The model gives satisfactory fits to experimental data and the simulations show that the transport of metals in soil is controlled by multiple competing biotic and abiotic reactions. These findings suggest that bioaccumulation and gas formation, compared to chemical precipitation, have a larger influence on hydraulic conductivity reduction.     

要强化减灾的非工程性措施

本文对我国目前在防减灾工程性措施方面存在的问题进行了分析探讨,阐述了在目前国情下强化减灾的非工程性措施的必要性和重要性,并对减灾的非工程性措施的具体作法进行了论述。