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1.
Incineration as a method of reducing Municipal Solid Waste (MSW) volume and recovery of energy has been developed gradually in China. More attention is paid on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans, (PCDD/Fs) formed in MSW incineration process. This paper presents results of the analysis of PCDD/Fs in the residues of a fluidized bed incinerator co-firing MSW and coal in the Yuhang Thermal Power Plant. The effects of operation conditions and the wet scrubber system on PCDD/Fs formation were also analyzed. PCDD/Fs emitting from the smoke stack was 0.92 I-TEQ ng/Nm3. After the wet scrubber emission of dioxins increased and the shifting of homologue profiles in flue gas was also observed, PCDFs were not detected in the incinerator residues. From this, we can see that in the MSW incineration process, the formation mechanism of PCDFs was different from that of PCDDs. The results will benefit further research on the optimal operation of incinerator and control of PCDD/Fs emission from the MSW incinerator. Project supported by the Special Funds for Major State Basic Research Projects 973. (G1999022211), and Natural Science Foundation of China (No. 59836210, No. N1986 2598780472).  相似文献   

2.
Based on the Industrial Source Complex Short-Term Version 3 （ISCST3） model, a simplified modeling approach was developed to predict concentrations of congeners of polychlorinated-p-dioxins and dibenzofurans （PCDD/Fs） of agricultural soil, within a radius of 3 kin from a municipal solid waste incinerator （MSWI） plant after its 4-year operation in Hangzhou, China. Comparisons were made between the measured and estimated congener-specific concentrations and the international-toxic equivalent （I-TEQ） values of soil samples with respect to distance from the stack. The results indicate that the predictions of soil PCDD/F concentrations and K-TEQ values were generally lower than their observations, and that the higher the degree of underestimation seems, the greater the further downwind one gets. Nevertheless, most of the predictions were in good agreement with the trend of measured ones and were within a factor of ten for samples located within 1 kin of the plant. Besides, analysis of contributions of various deposition pathways confirms that in addition to wet particle deposition, the dry gaseous deposition is essential for realistic prediction of PCDD/F depositions to soil, especially for tetra- and penta-chlorinated dioxins.  相似文献   

3.
The effects of SO2, SO3 on de novo synthesis of polychlorinated dibenzo-p-dioxins （PCDDs） and dibenzofurans （PCDFs） were studied using model fly ashes incorporating copper oxide and activated carbon. It was found that the inhibitive effect of SO2 on PCDD/Fs formation is similar to that of SO3. To investigate the inhibition mechanism, CuSO4 formations from both CuO and CuCl2 were examined. The ability of SO3 to convert CuCl2 and CuO on a silica support into sulfate is much stronger than that of SO2. However, replacing silica by activated carbon leads to a much high conversion of CuCl2 to CuSO4 in the presence of SO2. The promotion by activated carbon is explained by the reduction of CuCl2 to Cu2Cl2 and the eventual conversion of Cu2Cl2 into CuSO4 is the main inhibition mechanism of SO2 on de novo synthesis of PCDD/Fs.  相似文献   

4.
Polychlorinated dibenzo-p-dioxins and furans （PCDD/Fs） emissions in flue gas from two types of municipal solid waste incinerators （MSWIs） most commonly used in China were investigated in this study. The selected incinerators include two grate-type MSWIs： MSWI-A （350 t/d） and MSWI-B 050 t/d）, and two fluidized bed MSWIs： MSWI-C （400 t/d） and MSWI-D （400 t/d）, which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber （WS） as air pollutant control device （APCD）. Results indicated that the emission concentration and the international toxic equivalents （I-TEQs） of the PCDD/Fs from the stacks were in the range of 1.210-10.273 ng/Nm^3 and 0.019-0.201 ng I-TEQ/Nm^3, respectively. They were greatly lower than the emission regulation standard of PCDD/Fs in China （1.0 ng I-TEQ/Nm^3）. However, only the PCDD/Fs emission level from MSWI-C was below 0.1 ng I-TEQ/Nm^3. Although the homologue profiles were distinct, the contributions of the 2,3,7,8-subsituted congeners to the total I-TEQ were similar among all the investigated MSWIs. Two major 2,3,7,8-substituted congeners, 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD, account for 47% and 9% （average values） of the total I-TEQ values, respectively. The correlation between PCDD/Fs levels and composition of flue gas was also discussed.  相似文献   

5.
Polychlorinated dibenzo-p-dioxins and furalls(PCDD/Fs)emissions in flue gas from two types of municipal solid waste incinerators(MSWIs)most commonly used in China were investigated in this study.The selected incinerators include two grate-type MSWIs:MSWl-A(350 t/d)and MSWI-B(150 t/d),and two fluidized bed MSWIs:MSWI-C(400 t/d) and MSWI-D (400 t/d),which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber(WS)as air pollutant conffol device(APCD).Results indicated that the emission concentration and the international toxic equivalents(I-TEQs)of the PCDD/Fs from the stacks were in the range of 1.210～10.273 ng/Nm3 and 0.019～0.201 ngI-TEQ/Nm3,respectively.They were greatly lower than the emission regulation standard of PCDD/FS in China(1.0 ng I-TEQ/Nm3).However,only the PCDD/Fs emission Ievel from MSWI-C Was below 0.1 ng I-TEQ/Nm3.Although the homologue profiles were distinct,the contributions of the 2,3,7,8-subsituted congenem to the total I-TEQ were similar among all the investigated MSWIs.Two major 2,3,7,8-substituted congeners,2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD,account for 47% and 9%(average values)of the total I-TEQ values,respectively.The correlation between PCDD/Fs levels and composition of flue gas Was also discussed.  相似文献   

6.
INTRODUCTION Polychlorinated dibenzodioxins and poly- chlorinated dibenzofurans (PCDDs/Fs) are some major toxic substances unintentionally produced mainly from municipal solid waste incineration (MSWI). Attention has been focused on the best way for controlling and regulating such emissions. Among flue gas treatment technologies for post combustion zone emission control (Buekens and Huang, 1998; McKay, 2002), activated carbon adsorption (ACA) and techniques involving physical adsorp…  相似文献   

7.
二噁英是一类持久性有机污染物,因其低含量及复杂的成分使得分析难度加大。主要介绍了二噁英分析所使用的毛细管柱的类型及固定相,评价了各种柱子的优劣,并对柱子的选择给出了建议。  相似文献   

8.
根据福州市近年垃圾产量与成分,分析福州市生活垃圾焚烧可能出现的问题,提出应首先进行分类才能保证生活垃圾焚烧健康、稳定进行,建议采用分步走的方案。为了开展垃圾分类要教育、发动学生,媒体、各种环保组织和社区进行宣传发动和组织,政府建立相应的法规、政策以及采取相应的措施,实施垃圾分类和综合利用才能确保垃圾焚烧良性发展。  相似文献   

9.
A wastewater evaporation-desalination pretreatment method was introduced to remove the Na^＋ and K^＋ salts in volatile organic compounds （VOCs） wastewater before it was fed into the incinerator. VOCs in the wastewater were volatilized in the evaporation system and then the vapor was combusted in an incinerator. Simulated phenol wastewater containing sodium chloride was evaporated and concentrated and sodium chloride was crystallized in different parameters. The experimental results showed that the higher initial concentration of sodium chloride increases the ratio of volatilization of VOCs, which was due to the effect of “salting out” （a decrease in the solubility of the nonelectrolyte in the solution, or more rigorously, an increase in its activity coefficient, caused by the salt addition （Furter and Cook, 1967））. When evaporation speed was increased from 1.67 ml/min to 2.73 ml/min, the total removal coefficient of sodium chloride was about 99.88%-99.99%. This pretreatment procedure eliminates the slag phenomenon caused by Na^＋ and K^＋ salts during wastewater incineration, so the incinerator could operate continuously, and the wastewater evaporation could increase the heat value of wastewater, and the operation cost would be reduced.  相似文献   

10.
应用G98W程序包中的量子化学密度泛涵（DFT）方法，在B3LYP／6—31G（d）水平上，对51种二苯并呋喃及其衍生物（PCDFs）进行几何构型全优化。优化后所得分子的最高占据轨道能量、二苯并呋喃环上1，2，3，7四个原子静电荷密度作为PCDFa分子结构描述符。应用支持向量机构建多氯代二苯并呋喃logKow的定量构效（QSAR）关系模型，所建模型的预测值与实验值吻合的很好，经留一交叉校检法检验该模型，该模型具有良好的稳健性，有一定的应用价值．  相似文献   

11.
二噁英类有机污染物的TEF与QSAQ研究,通过定量结构活性相关模型,用简易量化方法,计算了83种典型二噁英的TEF毒性参数,并运用定量结构-性质相关技术研究了PCDDs-PCDFs的TEF,同logP、SHEIO氯原子数目、分子结构的定量关系。结果表明,二噁英化合物的毒性当量TEF同氯原子数目、logP有显著相关;同SEHIO和氯原子取代位置存在紧密相关。同时揭示二噁英的毒性是卤苯、苯酚、硝基苯、苯胺类衍生物毒性强度的50-70倍。  相似文献   

12.
城市固体废弃物的污染与防治   总被引：3，自引：0，他引：3  
本文主要介绍城市固体废弃物对环境造成的污染及其防治技术，并着重介绍了目前广泛采用的处理技术——垃圾焚烧及其优缺点：焚烧处理有明显的减容、减重、资源化的优点；然而焚烧产生的二恶英、重金属等却易产生二次污染。因此要用好焚烧这一技术，关键是善后，即彻底解决二次污染。本文就二次污染的控制技术也作了介绍。  相似文献   

13.
污泥焚烧炉温度控制过程中,由于投入污泥块热值不均以及外界环境干扰,传统的PID控制不能快速稳定地将炉温控制在所需范围内。为适应环境变化,实现更高效的炉温控制,提出一种基于NFOA-BP算法的污泥焚烧温度控制方法。该方法将改进型果蝇算法与BP神经网络结合,通过NFOA算法优化神经网络的初始权重和阈值,进而提高神经网络的全局搜索能力。将NFOA-BP算法应用于污泥焚烧炉温度控制系统,与传统PID温度控制系统进行仿真对比实验。结果表明该系统响应平稳、迅速,超调减小,正确率达到95%以上,比传统PID调节方法提高5%左右。  相似文献   

14.
ＩＮＴＲＯＤＵＣＴＩＯＮＢｒｏａｄｂｅａｎｗｉｌｔｖｉｒｕｓ (ＢＢＷＶ)ｉｓｔｈｅｔｙｐｅｍｅｍｂｅｒｏｆｔｈｅｇｅｎｕｓＦａｂａｖｉｒｕｓ.Ｉｔｈａｓａｗｉｄｅｈｏｓｔｒａｎｇｅａｍｏｎｇｄｉｃｏｔｙｌｅｄｏｎｓａｎｄｓｏｍｅｆａｍｉｌｉｅｓｏｆｍｏｎｏｃｏｔｙｌｅｄｏｎｓ,ａｎｄｉｓａｎｅｃｏｎｏｍｉｃａｌｌｙｉｍ ｐｏｒｔａｎｔｖｉｒｕｓｉｎＣｈｉｎａ (Ｚｈｏｕｅｔａｌ.,1 994 ) .ＢＢＷＶｈａｓｉｓｏｍｅｔｒｉｃｐａｒｔｉｃｌｅｓ,ｈｅｘａｇｏｎａｌｉｎｏｕｔ ｌｉｎｅａｎｄ 3 0ｎｍｉｎｄｉａｍ…  相似文献   

15.
针对垃圾焚烧发电厂循环流化床焚烧炉存在尾气温度过高的现象,对锅炉本体设备及尾部吸热设备进行技术改造,增加省煤器的吸热面积,达到降低尾气温度的效果,节省能耗,同时消除了尾气对环境的污染隐患。  相似文献   

16.
ＩＮＴＲＯＤＵＣＴＩＯＮＩｎｓｅｃｔｐｏｓｔｅｍｂｒｙｏｎｉｃｄｅｖｅｌｏｐｍｅｎｔｃｏｎｓｉｓｔｓｏｆｇｒｏｗｔｈｐｕｎｃｔｕａｔｅｄｂｙａｓｅｒｉｅｓｏｆｍｏｌｔｓｆｏｌｌｏｗｅｄｂｙｍｅｔａｍｏｒｐｈｏｓｉｓ.Ｔｈｅｓｅｍｏｌｔｓａｎｄｍｅｔａｍｏｒ ｐｈｏｓｉｓａｒｅｉｎｉｔｉａｔｅｄａｎｄｃｏｏｒｄｉｎａｔｅｄｂｙｈｏｒｍｏｎｅｓ(Ｒｉｄｄｉｆｏｒｄ ,1 994 ) .Ｉｔｉｓｇｅｎｅｒａｌｌｙａｃｃｅｐｔｅｄｔｈａｔｔｈｅｉｎｔｅｒｐｌａｙｏｆｅｃｄｙｓｔｅｒｉｏｄｓ,ａｇｒｏｕｐｏｆｓｔｅｒｏ…  相似文献   

17.
ＩＮＴＲＯＤＵＣＴＩＯＮＯｖｅｒｔｈｅｐａｓｔ 1 0ｙｅａｒｓ,ｔｈｅｓｅｍｉｃｏｎｄｕｃｔｏｒＴｉＯ2 ａｓａｐｒｏｍｉｓｉｎｇｐｈｏｔｏｃａｔａｌｙｓｔｈａｓｂｅｃｏｍｅｔｈｅｆｏｃｕｓｏｆｎｕｍｅｒｏｕｓｓｔｕｄｉｅｓｏｗｉｎｇｔｏｉｔｓｓｔａｂｉｌｉｔｙｉｎｖａｒｉｏｕｓｓｏｌｖｅｎｔｓｕｎｄｅｒｐｈｏｔｏｉｒｒａｄｉａｔｉｏｎ ,ｓｕｉｔａｂｌｅｒｅｄｏｘｐｏｔｅｎｔｉａｌａｎｄｍａｎｙｅｎｖｉｒｏｎｍｅｎｔａｌａｐｐｌｉｃａ ｔｉｏｎｓ,ｓｕｃｈａｓｓｏｌａｒｅｎｅｒｇｙｃｏｎｖｅｒｓｉｏｎ…  相似文献   

18.
ＩＮＴＲＯＤＵＣＴＩＯＮＴｙｐｅＩＩｓｕｐｅｒｃｏｎｄｕｃｔｏｒｓｉｎａｓｕｆｆｉｃｉｅｎｔｌｙｓｔｒｏｎｇｍａｇｎｅｔｉｃｆｉｅｌｄｃｈａｎｇｅｔｏａｍｉｘｅｄｓｔａｔｅａｎｄａｖｏｒｔｅｘｌａｔｔｉｃｅ (ＶＬ)ｆｏｒｍｓ .Ｔｈｅｉｎｆｌｕｅｎｃｅｏｆｑｕｅｎｃｈｅｄｒａｎｄｏｍｐｉｎｎｉｎｇｓｏｎｔｈｅｖｏｒｔｅｘｌａｔｔｉｃｅｉｓａｓｕｂｊｅｃｔｏｆｌｏｎｇｓｔａｎｄｉｎｇｉｎｔｅｒｅｓｔ.Ｉｎａｐｐｌｉｃａ ｔｉｏｎｏｆｈｉｇｈ Ｔｃｓｕｐｅｒｃｏｎｄｕｃｔｏｒｓｉｎｓｔｒｏｎｇｍａｇ ｎｅ…  相似文献   

19.
A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A continuous concentration change ofH＋ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value ofpH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics （CFD） tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber.  相似文献   

20.
The combustion behavior of typical components of MSW was examined with a thermal gravimetric analyzer (TGA). The experiments were done over the temperature range of room temperature to 1000℃ at a heating rate of 10 oC/min and in an oxidizing atmosphere. The results indicated that the entire weight loss process of each typical component of MSW consists of one to three distinct combustion stages. The combustion of typical components of MSW could be modeled by one to three independent reactions. The corresponding parameters of typical components of MSW such as activation energy, pre-exponential factor, and reaction order were determined. The calculated results using the comprehensive kinetic model composed of one to three independent and consecutive reactions, agreed well with experimental results.  相似文献   

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