宁夏典型工业园区污染物化学指纹数据库的建立

为评估工业园区污染状况及建立用于污染物溯源的数据库,以宁夏典型工业园区为研究区域,采集了7种不同行业类型的共398件土壤样品,检测了样品中的重金属和多环芳烃含量并建立污染物化学指纹数据库.结果 表明:除废弃资源综合利用业地块的二苯并[a,h]蒽外,样品中的重金属和多环芳烃均不超过第二类用地筛选值,但还是有部分污染物的含量超过宁夏土壤背景值和第一级标准值,污染现象依然存在.通过定义4种污染指纹等级,成功搭建了基于行业的污染物化学指纹数据库,为后期的污染治理及污染物的溯源提供了参考.     

宁夏典型工业园区污染物化学指纹数据库的建立

为评估工业园区污染状况及建立用于污染物溯源的数据库,以宁夏典型工业园区为研究区域,采集了7种不同行业类型的共398件土壤样品,检测了样品中的重金属和多环芳烃含量并建立污染物化学指纹数据库.结果 表明:除废弃资源综合利用业地块的二苯并[a,h]蒽外,样品中的重金属和多环芳烃均不超过第二类用地筛选值,但还是有部分污染物的含量超过宁夏土壤背景值和第一级标准值,污染现象依然存在.通过定义4种污染指纹等级,成功搭建了基于行业的污染物化学指纹数据库,为后期的污染治理及污染物的溯源提供了参考.     

种植区土壤重金属富集状况及生态风险评估

为调查种植区土壤重金属富集情况,采集该区域150份土壤样品,采用微波消解-ICP-MS法测定样品中Cd、Pb、As、Cr、Ni等5种重金属含量,并结合地累积指数法、污染负荷指数评价法和生态风险评价法对该区域的重金属污染情况进行评估。结果表明：该种植区的土壤含量均值未超过相关标准风险筛选值,而Cd、Pb、As、Cr、Ni等重金属含量均值分别为该区域的土壤背景值的1.3、0.8、0.98、1.36、0.87倍;各重金属地积累指数均值I_geo大小排序Cr>Cd>As>Ni>Pb;选用污染负荷指数(I_PL)来评价,150份土壤样品中强污染和中度污染样品数为4和18个,占比分别为2.7%和12%,表明该区域重金属污染差异性较大,小部分区域存在强污染,而大部分区域处于无污染状况。此外,采用生态风险指数评价各研究区域中5种重金属的综合潜在生态风险指数范围为0.16～316,潜在生态风险指数IR为3.304,其中各重金属对生态风险影响的大小排序为Cd>As>Ni>Cr>Pb,表明该区域主要重金属生态污染贡献者为...     

粉煤灰质农用地土壤污染状况分析及评价方法

在对某地粉煤灰农用地土壤进行系统取样检测的基础上,采用单因子污染指数法、加权法改进的内梅罗综合污染指数法和潜在生态危害指数法对项目区土壤中的重金属元素进行污染评价.结果 表明,该区域部分镉、汞、铅达到了轻度污染水平;33.3％样品P综处于1.17～1.67,重金属含量超过污染临界值,土壤与作物开始受到影响;11.1％的...     

某医疗废物处置企业土壤和地下水自行监测

为规范医疗废物单位建立土壤隐患排查制度,开展了企业土壤污染风险隐患排查和监测工作.通过企业重点区域和重点物质隐患识别确定企业污染物为重金属、二噁英、石油类.共布设监测点5个,地块内设置土壤监测点4个,地块外1个,水土共用点3个(含场地外背景点),采集19个土壤样品,4个地下水样品.监测结果表明:土壤中各污染物均未超过《...     

鸽粪基生物炭对土壤重金属形态的影响

基于鸽粪基生物炭的优良特性,进行模拟重金属污染土壤修复试验,研究了其对Cu、Zn、Pb、Cd的作用效果及土壤中赋存形态转化的影响.结果表明:鸽粪基生物炭中的CO_3^2-及OH-可与溶液中的Pb反应产生Pb的碳酸盐和氢氧化物沉淀;在重金属复合污染土壤中添加生物炭后,生物有效性最强的可交换态Cu、Zn、Pb、Cd含量分别降低98.48%、61.79%、89.15%和32.76%.生物炭中的灰分使土壤pH值显著升高(2.5~3.13),从而增加了碳酸盐结合态含量;而土壤有机质含量的升高(37.75%~178.43%)直接导致有机结合态含量增加;和500℃生物炭相比,400℃生物炭有机质含量更高,灰分含量更低.本研究的结果可以为鸽粪基生物炭在重金属复合污染土壤修复中的应用提供一定的理论基础,也为鸽粪固废处理开拓了新的思路.     

西南地区某重金属污染农田综合治理工程实例

本文以我国西南地区某重金属污染农田修复项目为例,介绍了该修复工程在实际应用中的具体操作,通过稳定化、污染阻隔和客土等措施,降低了污染农田土壤中的重金属含量,使种植农作物可食部分重金属含量均达到安全标准,旨在为以后类似污染农田提供参考.     

泉州市重点行业企业用地土壤污染调查及修复方案讨论

以泉州市为例,简要介绍了重点行业企业用地土壤污染调查工作的主要流程,并以调查成果中发现的污染物重金属铅和铬为例,提出相应的污染场地生态修复技术方案建议.对该市受污染场地土壤生态修复工作有一定的指导作用,为类似污染场地土壤污染风险调查及受污染场地生态修复工作提供借鉴.     

对环境水样中多环芳烃的分析研究

叙述了多环芳烃的来源、危害以及几种从水体中采集多环芳烃类有机污染物的实用技术、预处理方法和检测方法.     

正庚烷HCCI燃烧下芳香烃及多环芳烃形成的数值模拟

通过修改化学动力学软件CHEMKINⅢ,建立了正庚烷HCCI燃烧下排放特性数值模拟的多区模型.利用此模型对正庚烷HCCI燃烧下芳香烃(苯)与多环芳烃(萘、菲及芘)的生成及演变规律进行了详细分析.计算中采用了正庚烷的燃烧与分解、多环芳烃生成的详细反应机理(共包括107种组分、542个基元反应).结果表明,缸内压力变化趋势的计算结果与实验值基本吻合;核心区由于温度较高,其中的正庚烷已充分燃烧,多环芳烃的质量分数极小;边界层区和缝隙区温度较低,尤其是缝隙区,其温度与壁面温度保持一致,正庚烷在其中不能充分燃烧和分解,同时这两个区域成为多环芳烃的主要来源.     

浅析磨合期汽车的使用

如何合理使用磨合期的汽车，使其摩擦机件的磨损量能够平稳、均匀地磨合而不至于过度磨损，对汽车实际使用寿命有着重要的意义。从机器磨合期的特点和磨损机理出发，对汽车磨合期如何正确使用进行了有实际意义的探讨。     

10月份煤炭市场供需形势综述

通过对我国10月份煤炭产量的分析,表明我国煤炭市场需求增势强劲,价格呈现了持续攀升的良好势头,同时指出受市场供需及其他因素的影响,近期煤炭价格还会上涨,煤炭供应和销售问题仍应引起有关方面重视。     

Utilization of straw in biomass energy in China

China is a big agricultural country and one of the most abundant straw resources in the world, producing more than 620 million tons of straw in 2002, and representing about 33–45% of energy consumption for livelihood in rural areas. Utilization of straw as energy with high efficiency and rationality not only meets the demands for energy as the economy grows, but also provide a basis for environmental protection and sustainable development of society in China. This paper reviews the present utilized technologies of straw in biomass energy, including improved stove, biogas, straw gasification and straw briquette, which are already commercialized and popularized in China. Other technologies, such as liquefaction, straw carbonization and bio-coal, are also presented. Based on the technology status and potential, the future research and development of straw in the biomass energy portfolio in China are proposed.     

高压变频器在炼铁厂节能改造中的应用

叙述了高压变频器系统的功能与节能效益,指出高压变频器应用于除尘系统的技术改造可提高设备的自动控制水平,还能达到节能降耗的目的。     

Condensation of vapor in the presence of non-condensable gas in condensers

This paper presents a set of differential and algebraic equations that model heat and mass transfer in condensers in which a mixture of water vapor and non-condensable gas is cooled. The model has been used to predict the condensation rate, the bulk temperatures of the coolant and the gas–vapor mixture, and the surface temperatures of the condenser wall. The predicted results for counter flow tube condensers are compared with three sets of published experimental data for system in which air is the non-condensable gas. It is found that the predicted condensation rates and coolant bulk temperatures agree very well with all the three sets of experimental data, the predicted wall temperatures agree reasonably well with the experimental results, and the agreement between the predictions and the experimental results on the bulk temperature of the air–vapor mixture is excellent for one set of the experimental data, reasonable for the second set of experimental data, but poor for the third set of experimental data. It is suggested that the poor agreement between the predicted and measured bulk temperatures of the mixture for the third set of experimental data arises from the experimental errors. The results from this study show that when modeling vapor condensation in the presence of a non-condensable gas, a simple model for the mixture channel alone may not be sufficient since neither the temperature nor the heat flux at the wall can be assumed to be constant. The results also show that the wall temperature in the coolant channel can be quite high, and careful modeling of the heat transfer in the coolant channel is needed in order to achieve good agreement between the model predictions and the experimental results.     

Thermophoresis of particles in aqueous solution in micro-channel

A theoretical analysis of micro motion of particles under the action of thermophoresis in aqueous electrolyte solution is presented in this paper. A two-dimensional, incompressible and laminar fluid flow model is proposed to simulate the fluid flow and particle motion trajectory in micro-channel. The effects of thermophoretic force and viscous force on the particle are calculated. The particle trajectories considering the effects of particle size, inlet flow velocity and temperature difference between bottom side and top side in micro-channel with a length of 2000 μm and a height of 500 μm are simulated. The effect of thermophoresis on separation motion of particles in micro-channel is analyzed. The results show that thermophoretic force increases with the increase of temperature gradient in micro-channel and particles with smaller diameter, smaller density and smaller gravity acceleration can pass the micro-channel more easily.     

Energy economics of cooking in households in Nepal

This paper focuses on the economic analysis of energy consumed for cooking in urban households in Nepal. In this paper, annual energy requirements, energy efficiency, various combinations of fuels, stoves and utensils used for cooking and their corresponding costs have been examined through lab experiments and surveys. The estimate of system efficiencies for household cooking is one of the major contributions of this paper. The paper also discusses costs of energy use and compares various energy alternatives for cooking. It is believed that the analysis presented here will be helpful to the policy planners to devise better energy options for households.     

EMD在柴油机燃烧不良诊断中的应用

介绍了经验模态分解(EMD)方法的基本原理和实现过程,并应用该方法对柴油机气缸盖上面采集到的非线性非稳态复杂信号进行了分解,获得了线性稳态的本征模函数(IMF)信号。每个本征模函数信号包含了比较单一的故障特征,对其进行功率谱密度分析最终找到了产生剧烈振动的激振源激振频率。分析、判断激振的频率可以知道产生剧烈振动的最终原因为燃烧不良。现场拆装发动机缸盖部分发现喷油孔严重烧损,验证了结论的正确性。     

FHDO技术在混合二甲苯脱烯烃中的工业应用

催化重整生成油中富含芳烃和少量烯烃,要想生产合格的芳烃产品,必须脱除其中的烯烃。目前,广泛采用的脱除烯烃的方法是白土吸附和加氢精制工艺。抚顺石油化工研究院开发的FHDO技术,在成功应用于重整生成油苯、BTX等馏分脱烯烃基础上,首次在安庆石化1.0Mt/a催化重整装置混合二甲苯精制单元实现工业化应用。FHDO技术在较低反应温度(120~170℃)、反应压力(1.0~1.8MPa)、反应空速2~4h-1和氢油比(200~500∶1)下,生产出符合GB/T3407—2010的混合二甲苯产品。运行结果表明,HDO-18催化剂具有良好的活性和选择性,适用于催化重整生成油混合二甲苯馏分选择性加氢脱烯烃,FHDO技术可以有效替代常规的白土吸附和加氢精制工艺,从而彻底解决了常规混合二甲苯脱烯烃工艺中白土使用寿命短、需要频繁更换和废弃白土污染环境问题,以及加氢精制工艺在深度加氢脱烯烃过程中,带来的芳烃损失偏高等问题。FHDO技术的成功应用,填补了国内在催化重整生成油混合二甲苯馏分选择性加氢领域的空白,也是今后芳烃脱烯烃工艺的发展趋势。