两种垃圾焚烧炉灰渣的重金属成分与放射性检测

对8种重金属As、Hg、Mn、Cr、Cu、Cd、Co、Ni和Pb在两种垃圾焚烧炉灰渣中的浓度分布,浸出毒性及放射性进行检测.样品(炉渣和飞灰)分别取自北京(循环流化床焚烧炉CFBI)和深圳(炉排焚烧炉)两台不同燃烧方式的垃圾焚烧炉.研究表明,CFBI炉渣及飞灰中的重金属As、Mn、Cu、Cd、Co含量在炉渣中含量最低,中灰次之,飞灰中含量最高.重金属Hg在炉渣和飞灰中的含量相当,在中灰中的含量最低;Cr和Ni在炉渣中的含量也偏高,在中灰和飞灰中的含量相当Pb含量依中灰、炉渣和飞灰的顺序逐渐升高.浸出毒性检测结果显示,循环流化床垃圾焚烧后炉渣及飞灰中的重金属浸出毒性远低于国家标准1～2个量级,重金属总体排放量较低.炉排炉垃圾焚烧的炉渣及飞灰中的重金属含量却高很多,尤其是Cr、Pb、Cd和Cu.放射性检测结果表明,两种焚烧所产生的灰渣放射性均低于国家标准.在排放时无需作任何放射性方面的处理.最后,对焚烧灰渣的稳定化技术进行了讨论.     

提高垃圾焚烧电厂热能利用效率的几个途径

采用能量分析的方法,从几个侧面对垃圾焚烧发电厂热能利用效率低下的原因进行分析,提出了解决垃圾焚烧发电厂热能利用效率的途径:选择合适的炉型,降低散热损失以提高锅炉效率;对进厂垃圾进行堆酵以沥出其中水分,提高入炉垃圾低位热值;提高锅炉出口蒸汽参数,采用回热循环等措施增加蒸汽的可用能,提高系统发电效率。     

污泥掺烧对焚烧后固体废物污染物排放的影响

在佛山某生活垃圾焚烧发电厂开展生活垃圾掺烧市政污泥工业试验,分析5%、10%、15%的市政污泥掺烧对电厂焚烧后固体废物中重金属和二噁英排放的影响。结果表明,掺烧污泥使Cd在飞灰中的分布提高了40%以上,但其他重金属的分布特征仍主要受各自沸点的影响。焚烧固废中重金属含量受污泥的引入影响普遍不显著,飞灰中Cu浸出质量浓度上升20%,Ni、Pb、Hg、Cr的浸出质量浓度波动下降;炉渣中重金属浸出质量浓度波动较大。焚烧飞灰中总二噁英含量与污泥掺烧比例成负相关,且与投料中的Cl质量分数成正相关,与S质量分数成负相关。因此,低于15%的污泥掺烧比例不会显著提升焚烧固废中污染物排放浓度。     

生活垃圾焚烧发电厂烟尘中重金属沉降对土壤环境影响分析

本文以一日处理生活垃圾2250t的生活垃圾焚烧发电厂为例,根据其重金属的排放量,预测重金属随大气扩散、迁移,最终通过自然降水和自然沉降进入土壤后,对土壤环境的影响。结果表明,项目建成后的20年内,大气评价范围内土壤中重金属的累计值满足《土壤环境质量建设用地土壤污染风险管控标准(试行)》 (GB36600-2018)表1中第二类用地筛选值要求。     

LFX-20型逆燃式医疗废物焚烧炉二恶英实测分析

概述我国目前医疗废物焚烧处置中的主要炉型,着重介绍LFX-20型逆燃式焚烧炉焚烧处置医疗废物的实际运行工况。在1燃室、2燃室平均温度分别为869.5℃和898.7℃条件下,对医疗废物焚烧烟气进行检测。各项常规指标均低于国标限值,二恶英检测中其质量浓度实测值为15ng/m3,相应毒性当量为0.46ngTEQ/m3,同时对医疗废物焚烧后产生烟气中二恶英和灰渣的检测结果进行了分析,焚烧后底渣体积约为焚烧前医疗废物体积的1/10,重量为原来的12%～18%,飞灰热灼减率为34.6%,并给出分析结果。     

垃圾焚烧飞灰处理处置研究进展

针对作为危险废物的垃圾焚烧飞灰,介绍了近年来国内外对其进行处理处置的研究情况.飞灰的固化/稳定化处理主要从水泥(沥青)固化、熔融固化及化学药剂固化几方面进行论述,飞灰中重金属的提取主要从酸碱浸提、生物浸提、螯合剂浸提及电渗析法提取几方面进行论述.     

北京市生活垃圾焚烧飞灰安全处置技术路线分析

调研了北京市生活垃圾焚烧处理及飞灰产生现状、污染特性以及处置方式,剖析了现行飞灰环境管理的技术政策标准法规,对比分析北京市目前处置生活垃圾焚烧飞灰采用的固化/稳定化—填埋和水泥窑协同处理两种技术路线,结合北京市水泥窑协同处置生活垃圾焚烧飞灰实例,深入分析了水泥窑协同处置生活垃圾焚烧飞灰技术路线及存在问题,分析了改进后的水泥窑协同处置方式的技术特点。文章最后提出北京市生活垃圾焚烧飞灰处置应选择适宜的技术路线、加强相关技术规范和标准制定和完善与推广安全可行的飞灰资源化处置技术等对策建议。     

城市生活垃圾焚烧灰渣熔融特性的分析

分析了城市生活垃圾焚烧灰渣熔融过程中CaO、SiO2、Al2O3等主要成分以及实验气氛对熔融特性的影响,并分析了熔渣的物理化学性能.实验结果表明,灰渣中CaO含量的高低决定了灰渣的酸碱度和灰渣的熔点.当CaO的质量分数占灰渣总量的33%左右,灰渣的熔融温度最低;而灰渣中总碱性氧化物的质量分数低于48%时,生活垃圾焚烧灰渣熔点随碱性氧化物质量分数的增加而降低;而当碱性氧化物质量分数大于48%时,碱性氧化物对生活垃圾焚烧灰渣熔点的影响则相反.以SiO2、Al2O3等氧化物为代表的酸性氧化物,其含量在生活垃圾焚烧灰渣中已经饱和,硅铝氧化物的添加,则会升高灰渣的熔点.为了降低灰渣的熔点,应将灰渣的酸碱度控制在1左右,并在弱还原性的气氛下进行熔融处理.熔融处理后的熔渣因具有性能稳定,重金属浸出量低,几乎不含有二噁英类毒性有机物,完全可以直接成为可利用再生资源.     

Safety lessons and reflections following incinerator vent commissioning in a chemical plant; a case study of a complex socio-technical system

In a bulk chemical plant producing resins, a flashback from an incinerator through the vent system into the reactor hall occurred during commissioning of a newly installed vent header system. The original design of the vent header system was seriously flawed not being in line with current practice. Subsequently the vent header was re-designed into a rich/lean vent header system. This paper explores the reasons behind a number of incidents and near misses that occurred during both the commissioning of a vent header system and its recommissioning following system re-design. Furthermore, it reflects on some broader implications for approaches to safety around what can be recognised as complex socio-technical systems.     

生活垃圾焚烧飞灰重金属在浸出柱中的浸出规律

通过浸出柱实验,研究生活垃圾焚烧飞灰中重金属的动态浸出规律.结果表明,浸出液中各种重金属的质量浓度均随浸取剂与飞灰比值(L/S)增大而减小,并在L/S＞2后趋于稳定.除Pb外,浸出质量浓度均低于污水综合排放标准(GB 8978-1996)限值.对比原灰与浸出残留物重金属多级提取结果表明,飞灰的重金属在浸出柱实验中释放能力由强到弱依次为:Cd、Ni、Cu、Pb、Zn和Cr.受浸取剂pH值和固液接触方式影响,浸出柱重金属累计浸出量都小于国家标准(GB 5086.2-1997)浸出量(Cd除外),尤其Cr、Hg和Pb的浸出柱累计浸出量分别是国标浸出量的23.25%、1.29%和14.29%     

垃圾焚烧飞灰的处理技术现状

系统论述了国内外垃圾焚烧飞灰的处理现状,从固化稳定化、湿法化学处理、安全填埋等几个方面分析了垃圾焚烧飞灰在各个技术领域的利用情况,以及以后的处理方向和发展前景,并且对各项技术的利用情况作了详细的阐述.     

A superstructure model for the synthesis of single-contaminant water networks with partitioning regenerators

This paper presents a novel superstructure-based optimization model for the synthesis of industrial water networks with partitioning regenerators. Such regenerators function by splitting a contaminated water stream into a regenerated lean stream and a low-quality reject stream. Membrane separation-based processes are examples of these types of regenerators. The optimization model presented in this work integrates a single, centralized partitioning regenerator with a source–demand superstructure under the assumption that the processes within the plant are of the fixed flow rate type. The formulation is non-linear as a result of the presence of bilinear terms in the regenerator balance equations, but global optimal solutions can be found using commercial software. The features of the model are illustrated by solving case studies from the literature. It is notable from these examples that considerable design flexibility exists in networks of this type, since potentially both the lean and reject streams from the partitioning regenerator can be reused/recycled within the plant.     

A general kinetic law for heavy metal vaporization during municipal solid waste incineration

Metal emissions from waste incineration plants become a great environmental concern because of their toxicity for both human health and environment. Metals are not destroyed by high-temperature thermal treatment and some vaporized metals may be emitted. It is thus essential to understand the release mechanism of metals during high-temperature waste treatment, in order to improve the understanding of their behavior and the control of their emission. The objective of this study is to identify the kinetic law for metal release from realistic artificial waste. The vaporization of three metals of most concern (Cd, Pb and Zn) during municipal waste incineration was studied. The vaporization rate at the particle level was determined from the experimental concentration profile in the outlet gas of a fluidized bed reactor, by using the inverse method that was previously developed and validated by our team. As a first step, the kinetic parameters were determined thanks to experiments carried out at several temperatures. Specific laws, for each studied metal, were thus obtained as a function of temperature. Nevertheless, it is very useful to identify all the experimental kinetic curves (all studied metals at all temperatures) to one single mathematical law. Therefore, a general kinetic law, expressing the solid matrix influence on the metal vaporization dynamic, was determined as a second step. It permits to predict the vaporization characteristic time and the time course of the metal concentration in the waste.     

生物质气化灰的肥效试验研究

通过试验对生物质气化发电的副产物--生物质气化灰的肥效进行研究.结果表明,在施肥量相同的条件下,添加生物质气化灰的试样,除黄瓜外,空心菜、油麦菜、樱桃萝卜、上海青试样的发芽时间都略早于单施化学肥料的试样; 后期长势也明显优于单施化学肥料的试样,叶片厚而有光泽; 前者在生长过程中没有虫害现象,后者有虫害现象.在生物质气化灰中添加氮、磷的试样比施单一肥料的试样长势好.研究表明,生物质气化灰具有替代钾肥的广阔市场前景.     

Analysis of gas dispersion and ventilation within a comprehensive CAD model of an offshore platform via computational fluid dynamics

Maintaining an adequate air flow with a desired air quality that is free from hazardous gases is among the most important actions taken toward the improvement of safety in any process plant. Due to the increased focus on the consequences of existing hazardous material on safety, health, and the environment, air quality and sufficient ventilation within a plant has been increasingly considered in the design stage. This paper investigates and analyzes methane and hydrogen sulfite dispersion and the effect of air ventilation within a CAD model of an offshore platform using computation fluids dynamics (CFD). In addition, this method and its principals could be utilized in any other hazardous environment. Simulations of possible hazardous events along with solutions for preventing or reducing their probability are presented to better assess the data. These investigations are performed by considering hypothetical hazardous scenarios which consist of gas leakages from pipes and process equipment under different conditions. After drafting a precise and highly detailed CAD model of the plant and performing CFD simulations on this model, the results of gas behaviors, dispersion, distribution, accumulation, and its possible hazards are investigated and analyzed. The larger amount of details of the actual plant model in CFD simulation are obtained by using a combination of different methods and software. These include PDMS for 3-D drawing of the plan, Rinoceros for geometrical integration of the process equipment and facilities, and Sharc Harpoon which meshes the model. Moreover, the probability of inducing ignitable or toxic concentration of gases within the atmosphere and air ventilation of the unit is considered by these investigations.     

日本一家垃圾焚烧厂二恶英污染的探讨

二恶英污染主要来源于垃圾焚烧，介绍了日本一家垃圾焚烧厂二恶英污染情况，分析了产生的原因，并提出改进方案。     

A chemical plant protection game incorporating bounded rational attackers and distribution-free uncertainties

The chemical industry has an important role in our modern society. Due to the existence of hazardous materials and possible extreme producing conditions, chemical facilities are also considered dangerous. Research has pointed out that a successful attack on chemical plants may cause mass casualties, in the United States. Game theory has been employed to improve the protection of chemical plants, and current literature on chemical plant protection games assume a ‘rational’ attacker. The present paper studies a game-theoretic model, which is played by a rational defender and a ‘bounded rational’ attacker, for improving chemical plant protection. The attacker modeled in this paper is assumed to play higher payoff strategies with higher probabilities, which is innovative from the current chemical security literature. Attackers in the current chemical plant protection games would always play the strategy with the highest payoff (probability of 100%). Distribution-free uncertainties on attacker's parameters are also integrated into the model. An algorithm for solving the game presented in this paper is also proposed. A case study reveals that although a bounded rational attacker would reduce the defender's expected payoff, the defender's equilibrium strategy from the present model is robust to different attacker behaviors.     

A New Safety Risk Index for Use in Petrochemical Planning

Risk analysis is being used to evaluate and manage the potential of unwanted events in the chemical processing industry. The risk in this study is the risk posed by chemical plant accidents and it is presented in a simple quantitative form. A safety risk index is formulated that represents the maximum number of people that might be affected if an accident occurred that caused the release of all the plant inventory of a chemical. The index has four terms: frequency of accidents; hazardous effect of the chemical; inventory of the chemical released; size of the plant. The overall unit of the index is expressed as the number of people affected per year from the plant operation and is formed in a particularly simple manner so as to be suitable for the comparison of safety risk within a model for planning the development of the petrochemical industry.     

化工项目施工作业风险分析

化工项目施工过程中存在动态变化的、相互叠加的、集成化的作业风险。以往的研究缺乏对动态、叠加风险的全面考虑和定量分析,难以满足化工项目施工中特定风险管理的现实要求。为有效地管理和控制化工项目施工作业风险,分析施工作业在时间、空间上的变化和叠加现象,以作业风险模型为基础,建立兼顾动态风险和叠加风险的系统性作业风险模型。运用该模型计算某个实例化工项目施工期典型时段各建设单元前后期风险变化值及其相互叠加的风险值,绘制其施工区域风险分布图。结果表明,当前主生产车间、辅助车间、喷塔楼、2号仓库区域设备集中、人员密集、作业交叉、事故发生风险较高,是安全管理的重点部位。就此,提出具体风险控制措施。     

垃圾焚烧发电厂循环流化床焚烧炉优化改造

针对垃圾焚烧发电厂循环流化床焚烧炉存在的炉膛内部受热面吸热份额较大和受返料器影响的问题,重点进行减少掺煤量的焚烧炉燃烧室优化改造,进一步控制污染排放,达到节能降耗,取得了较好的经济效益。