Metrics and analytics for process hazard analysis

Process hazard analysis (PHA) studies (e.g. HAZOP) identify hazard scenarios and each scenario is examined individually to decide whether risk reduction measures are needed. However, much more can be done to benefit from the contents of studies.PHA studies contain so much data that a manual review is precluded from yielding insights into their results. Fortunately, valuable information can be extracted using metrics and analytics that consider all the contents of a PHA study. The management of safety, operability, reliability, utilization, and loss prevention can all be improved.Metrics evaluate the contents of PHA studies to provide insights into the safety of processes and the quality of studies. Measures of process safety and study quality can be compared with norms to identify possible departures that may need to be addressed.Rather than focusing decision making on the risks of individual hazard scenarios, as is common practice, analytics enable a deeper analysis of the entire set of scenarios for a process. This enables better decisions to be made on where and how risk reduction resources should be allocated. Analytics can also be used to prioritize maintenance, training, and other activities.Various analytics and metrics for PHA studies are described together with examples that illustrate their use.     

危险分析AHP模型

采用层次分析法（ＡＨＰ），建立危险分析的ＡＨＰ模型，实现对危险因素的定性和定量相结合的全面分析，排列出危险因素的重要性的顺序，从而为消除潜在的事故危险性提供思路和依据     

SBR及其改良型技术分析

通过分析研究SBR及其衍生的各种改良型技术用于污水处理的运行方式及特点,指出SBR及其衍生的改良型技术可在中小型污水处理领域降低建设成本和运行费用,是一种适合中国国情的绿色小区污水回用处理技术.     

黄河三角洲土地资源开发对策的探讨

黄河三角洲是我国三大三角洲之一,面积约5930km²,它拥有丰富的土地资源,但从大农业角度来看,其土地质量较差,生态环境脆弱。当前,其土地资源的合理开发利用具有十分重要的现实意义。 首先,本文将区内土地类型划为 5类和19个亚类。其次,应用二级模糊综合评判,将其土地质量分为8等13级。其中宜农地占28.83％,宜牧地占34.44％,渔业用地占27.98％。最后,应用层次分析法（AHP）对土地资源合理开发利用的对策作了分析探讨。认为:对于黄河三角洲土地资源的开发,必须强调遵循经济效益服从社会效益和生态效益的总原则。在此前提下,提出了以保证工矿业用地为首的6项开发策略,以及以引黄放淤改良盐碱地为首的20项开发措施。     

污水处理的改良型SBR工艺

简要介绍了一种新型污水处理工艺———改良型序批式活性污泥法。主要介绍了它的结构组成、流程控制、生物脱氮除磷基本原理、自动化管理。     

厌氧水解-活性污泥法的生命周期能耗分析

运用生命周期分析技术可从全过程的视角识别和比较不同城市污水处理工艺在其生命周期各个阶段的能耗 ,并在此基础上提出改善其能效的措施。本文运用LCA方法对厌氧水解 -活性污泥法处理系统从其原材料开采和加工开始直至污水厂施工建设、处理运行以及废弃拆除的LC全过程能耗进行了识别和量化分析 ,并与普通活性污泥法进行了平行对照。研究结果表明 ,在微孔和穿孔管两种曝气条件下与普通活性污泥法相比 ,厌氧水解法的LC能耗分别节省 14.0 %和 17.6%。由于污泥产量较低 ,厌氧水解法的比能耗大幅度提高 67.7%～ 77.7%。     

制药行业中污水处理技术及实践

采用物理灭活与生物处理相结合的废水处理技术对药厂污水进行处理,高温灭菌灭活了废水中的病毒、病菌等,生化处理化解污水中大分子的有机物.工程实践表明:两者相结合的处理方法,处理后的水质能够达到国家污水综合排放二级标准.     

螺旋钢管盘制成形的一种新方法

对如何在三辊卷板机上进行盘制螺旋钢管、盘管所用模具及成形工艺作了介绍.     

Ferrioxalate-mediated photodegradation and mineralization of 4-Chlorophenol

INTENTION, GOAL, SCOPE, BACKGROUND: Advanced oxidation processes are powerful methods which are capable of transforming refractory, nonbiodegradable and/or toxic organic compounds into harmless end products such as carbon dioxide and water. However, one commen problem of all advanced oxidation processes is the high demand of electrical energy for ultraviolet lamps, which causes high operational costs. Minimization of the required irradiation time, and therefore the energy consumption, by optimization of other reaction conditions such as catalyst-oxidant type and concentration, pH, temperature, pollutant/oxidant ratio etc., therefore continues to gain importance. OBJECTIVE: The main objective of this study was the minimization of the required irradiation time through optimization of the use of a newly patented catalyst, ferrioxalate, and also to compare the performance of this catalyst with the performance of other AOPs. METHODS: Oxidation of 4-chlorophenol by photo-Fenton process using potassium ferrioxalate as a mediator was studied in a lab scale photoreactor. The influence of parameters such as hydrogen peroxide and ferrioxalate concentrations, initial pH, power-output, oxalate/iron ratio and different iron sources was evaluated. An upflow photoreactor equipped with a 1000 Watt high-pressure mercury vapour lamp and operating in a recirculation mode was used during photodegradation experiments. The extent of the reduction of 4-chlorophenol, Total Organic Carbon and Chemical Oxygen Demand was used to evaluate the photodegradation reaction. RESULTS AND DISCUSSION: The optimum pH range observed was found to be 2.7-3. The efficiency of 4-chlorophenol oxidation increased with increasing concentrations of hydrogen peroxide and ferrioxalate, reaching a plateau after the addition of 10 and 0.072 mM of those reagents, respectively. Using an Oxalate/iron ratio of 12 was 18% less efficient than using a ratio of 3:1. The efficiency increased with increasing radiation power. However, this increase was not linear. The UV/ferrioxalate/H2O2 process, by which complete mineralization of 100 mg l(-1) 4-chlorophenol was achieved in 20 min of total reaction time, was the most efficient process among the alternatives applied. CONCLUSIONS: The use of ferrioxalate as the catalyst was found to be more efficient than the use of Fe(II) and Fe(III) iron species. It was possible to completely mineralize 4-chlorophenol. RECOMMENDATION AND OUTLOOK: The results of this study demonstrate that the ferrioxalate-mediated degradation of 4-chlorophenol requires less irradiation times than other advanced oxidation processes. There are mainly 19 phenol isomers and other toxic and nonbiodegradable organic compounds. We recommend that similar studies should be performed on many such compounds in order to attain a clear understanding of the performance of this catalyst. Because of its light sensitivity, this catalyst should be used immediately after its preparation. The use of low pressure mercury vapour lamps in this process should also be considered, since low power outputs may be enough for the process.     

广西贵港市土地利用总体规划实施评价

目前沿用的土地利用总体规划实施评价的方法多为定性的直接描述法，缺乏科学的评价体系，难以对规划实施的效果作出客观、科学的评判。文章引入层次分析法（AHP），对贵港市土地利用总体规划实施效果进行量化研究。结果表明，虽然当地政府高度重视规划的实施，实施情况总体良好，但社会经济成效指标和完成性指标评价得分较低。建议该市今后加快“三农”政策的落实，以提高农民种粮的积极性和农民的收入水平；加大土地开发复垦、退耕还林资金投入，并制定有力的保障措施，促进完成性指标的实施。同时，提高社会意识度，是规划实施工作的重中之重，今后的规划要强化公众参与。