A hybrid model for human factor analysis in process accidents: FBN-HFACS

Human factors are the largest contributing factors to unsafe operation of the chemical process systems. Conventional methods of human factor assessment are often static, unable to deal with data and model uncertainty, and to consider independencies among failure modes. To overcome the above limitations, this paper presents a hybrid dynamic human factor model considering Human Factor Analysis and Classification System (HFACS), intuitionistic fuzzy set theory, and Bayesian network. The model is tested on accident scenarios which have occurred in a hot tapping operation of a natural gas pipeline. The results demonstrate that poor occupational safety training, failure to implement risk management principles, and ignoring reporting unsafe conditions were the factors that contributed most failures causing accident. The potential risk-based safety measures for preventing similar accidents are discussed. The application of the model confirms its robustness in estimating impact rate (degree) of human factor induced failures, consideration of the conditional dependency, and a dynamic and flexible modelling structure.     

Density functional theory (DFT) studies of vanadium-titanium based selective catalytic reduction (SCR) catalysts

Based on density functional theory (DFT) and basic structure models, the chemical reactions on the surface of vanadium-titanium based selective catalytic reduction (SCR) denitrification catalysts were summarized. Reasonable structural models (non-periodic and periodic structural models) are the basis of density functional calculations. A periodic structure model was more appropriate to represent the catalyst surface, and its theoretical calculation results were more comparable with the experimental results than a non-periodic model. It is generally believed that the SCR mechanism where NH₃ and NO react to produce N₂ and H₂O follows an Eley-Rideal type mechanism. NH₂NO was found to be an important intermediate in the SCR reaction, with multiple production routes. Simultaneously, the effects of H₂O, SO₂ and metal on SCR catalysts were also summarized.     

铁路运输业污水治理系统分析

研究了乌鲁木剂铁路局系统污水治理污染控制方法及途径，提出了主要污染物为石油类，其最佳治理对策是：确定重点污染单位、污染源、用最低的治理投入，选择斜板隔油气浮工艺治理重点污染和次重点污染部门，得到较好的治理效果，否定盲目追求“零排放”的高投入方案。     

含柠檬酸盐电镀废水的处理

对含柠檬酸盐电镀废水的几种处理方法的比较表明,氯化钡添加法能较好地使柠檬酸盐沉淀,操作简便,处理效果理想,其柠檬酸根离子的去除率达98％以上。     

膨润土吸附－絮凝法处理污水中的重金属离子

研究了天然膨润土对Ｐｂ￣（２＋）、Ｃｄ￣（２＋）、Ｃｒ￣（３＋）的吸附和膨润土的絮凝沉降条件，将吸附与絮凝过程结合起来形成处理污水的新工艺，加入０．０４％膨润土和０．００６％的ＰＡＣ可使低浓度污水中Ｐｂ￣（２＋）脱除９３．１％。     

SBR法处理中药材有机废水工艺研究

应用ＳＢＲ法对中药材有机废水进行了研究。考察了ＣＯＤＣＲ、ＢＯＤ５、ＳＳ、ＮＨ３－Ｈ的处理效果，以及ＰＨ、水温、污泥负荷等条件对去除率的影响。运行结果表明，ＰＨＯ ６．０－９．０、ｔ为１５－３０℃、污沁荷０．３ｋｇＢＯＤ５／ｋｇＭＬＳＳ．ｄ，运行程序：进水０．５ｈ（限制曝气）、曝气１０ｈ、脱氮１．５ｈ，沉降０．５ｈ，排水０．５ｈ、闲置１１ｈ，周期时间２４ｈ时ＣＯＤＣＲ去除率８８％、ＢＯＤ５９４％、     

冷摆辗模具的材料选择及其热处理

模具寿命是冷摆辗的关键问题之一。选择合理的模具材料以及采用适宜的热处理工艺可以提高冷摆辗模具的强韧性,从而提高模具寿命。基于摆动辗压工艺的基本原理,分析研究了冷摆辗模具的受力情况,并对冷摆辗模具材料的选择及热处理工艺作了探讨。     

清洁生产工艺在造纸工业中的应用

介绍了清洁生产这个新概念,清洁生产工艺在造纸工业中的应用,实例表明:造纸废水再循环,不准能节约水资源,节约能源,防止环境污染,而且可以取得良好的经济效益和社会效益,为造纸废水在2000 年前达到国家排准排放奠定了良好基础     

餐饮废水处理技术探讨

介绍了我国餐饮业的发展趋势，指出餐饮废水已经成为城市的主要高浓度污染源之一，同时适当地讨论了目前餐饮废水处理技术研究的现状以及处理系统的技术要求，最后提出了对不同规模的餐饮废水处理的适当方法。     

SBR工艺处理城市垃圾渗滤液的可行性分析

在参考国内外垃圾渗滤液的处理方案后，选择厌氧预处理 SBR工艺作为处理方案，通过实验对该废水处理的情况来看，该工艺较好地适应了垃圾渗滤液的处理特点，能达到比较良好的效果。