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191.
分析了济钢中板厂精整区噪声污染严重的原因。采取了吸音材抖、消声设备、加强个体防护等措施,使总声压级由105dB降到72dB,保护了职工的身体健康。  相似文献   
192.
无纺布填料处理污水试验及机理   总被引:4,自引:0,他引:4  
采用无纺布作为一种新型悬浮填料,探索无纺布填料处理污水的适用条件、运行参数及降解机理.研究认为不同容积负荷应采取不同的填料投配率:当CODCr容积负荷低于1.2kg/(m3·d)时,取填料投配率为20%;当CODCr容积负荷在1.2~2.0kg/(m3·d)之间时,取填料投配率为38%;当CODCr容积负荷达2.0 kg/(m3·d)以上时,取填料投配率为29%模型结果表明,附着微生物降解有机物的规律可用Monod方程的形式描述.  相似文献   
193.
In this work we investigated the chemical, thermal and toxic properties of dried sewage sludge (DSS), the preparation and properties of lightweight sludge ceramic (LSC) and the mechanisms of action of the organic and inorganic foaming agents (OFAs and IFAs). The chemical components and thermal properties of the raw materials were studied by Energy Dispersive X-ray Detection (EDX) and Thermogravimetric Analysis and Differential Scanning Calorimetry (DSC/TGA). The mineral phases of the raw materials and the formed ceramics were determined by X-ray Diffraction (XRD). The leaching characteristics of heavy metals were investigated with Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES). Different ratios of DSS and clay were mixed and pressed into raw pellets. After drying and preheating treatment, the raw pellets were sintered at 1150°C for 10 min. The physical properties of LSC (50 wt% DSS added) were tested. The results showed that when the addition of DSS was above 50 wt%, LSC began to shrink, and a maximum density occurred. The environmental safety of LSC was satisfactory. XRD showed that some new mineral phases formed in the LSC. Observation of the microstructure by Scanning Electron Microscope (SEM) indicated that the body of LSC was porous.  相似文献   
194.
周巍  姚斌 《火灾科学》2018,27(1):23-29
生产企业常在电缆或者贵重高危机器处设置防火布来保护生产设备设施的消防安全,选取五种常用的防火布:石棉纤维防火布、陶瓷纤维防火布、硅胶防火布、涂胶防火布、碳素纤维防火布,通过锥形量热仪实验研究不同辐射强度对防火布燃烧性能的影响。结果表明:点燃时间的均方根倒数与辐射强度之间呈现线性关系;在35 kW/m~2辐射强度工况下,碳素纤维防火布的热释放速率最大,达到272.59 kW/m~2,有效燃烧热的峰值也最大,达到529.52 kJ/g;综合比较各样品的燃烧性能,防火能力强弱顺序为:硅胶防火布石棉纤维防火布陶瓷纤维防火布碳素纤维防火布涂胶防火布。  相似文献   
195.
纺织品抗拒挥发性有机化合物沾染整理方法的研究   总被引:1,自引:1,他引:0  
频繁接触挥发性有机化合物的工厂作业岗位上的工人,所穿着的服装容易粘附有害的有机物质分子,进而危害工人的健康。为解决这一问题,本文探索采用变化服装面料的织造工艺、面料织物与聚四氟乙烯微孔薄膜复合以及含氟织物整理剂整理等方法,制作具有一定抗挥发性有机化合物沾染性能的防护服面料。实验中对不同纤维原料的织物,在未经整理和进行覆膜或含氟织物整理剂整理后,分别剪取样品放置在充满有机气体的氛围中熏蒸24小时,用二硫化碳萃取布料上的有机物,并使用气相色谱分析仪分析这些物质的含量。经过比较,发现克重较低、与聚四氟乙烯膜复合以及经含氟织物整理剂整理的布料,其抗拒挥发性有机化学物质沾染的能力均有所增强。综合使用这些处理方法,有望制作出具有理想的抗有机化学物质沾染的防护工作服,用于经常接触这类物质的工厂工人的日常劳动防护。  相似文献   
196.
3种刺激性化学战剂对藻类的急性毒性研究   总被引:1,自引:1,他引:0  
采用国际通用的试验藻种斜生栅藻(Scendesmus obliuus)作为试验生物,研究了3种刺激性化学战剂(二苯氰胂、二苯氯胂和苯氯乙酮)对试验藻类的急性毒性.结果表明:二苯氰胂、二苯氯胂和苯氯乙酮对斜生栅藻急性毒性试验的96 h半数生长抑制浓度(EC50)分别为0.14,0.10和0.36mg/L,表明这3种化学战剂均属于极高毒性物质,其毒性依次为二苯氯胂>二苯氰胂>苯氯乙酮,但其毒性均在同一数量级上,区分度不强.   相似文献   
197.
Chelant-aided enhancement of lead mobilization in residential soils   总被引:3,自引:0,他引:3  
Chelation of metals is an important factor in enhancing solubility and hence, availability to plants to promote phytoremediation. We compared the effects of two chelants, namely, ethylenediaminetetraacetic acid (EDTA) and ethylenediaminedisuccinic acid (EDDS) in enhancing mobilized lead (Pb) in Pb-based paint contaminated residential soils collected from San Antonio, Texas and Baltimore, Maryland. Batch incubation studies were performed to investigate the effectiveness of the two chelants in enhancing mobilized Pb, at various concentrations and treatment durations. Over a period of 1 month, the mobilized Pb pool in the San Antonio study soils increased from 52 mg kg−1 to 287 and 114 mg kg−1 in the presence of 15 mM kg−1 EDTA and EDDS, respectively. Stepwise linear regression analysis demonstrated that pH and organic matter content significantly affected the mobilized Pb fraction. The regression models explained a large percentage, from 83 to 99%, of the total variation in mobilized Pb concentrations.  相似文献   
198.
Goal, Scope and Background  Complexing agents are one of the major environmental concerns in electrolytic and chemical surface treatment (ECST) industry; e.g. the EU reference document on the best available technology (BREF) pays special attention to the usage of EDTA. However, no comprehensive studies are available on usage of EDTA or other complexing agents or their load to the receiving waters from ECST industry. In this study, the concentrations of complexing agents were analyzed to get an overview of their usage and load and also to recognize their relevance in the environmental permitting and compliance monitoring of such facilities. Methods  Complexing agent concentrations of treated waste water samples of 23 ECST plants with vat volume exceeding 30 m3 was studied. HPLC and GC-MS were used to analyze and identify complexing agent concentrations, ICP-AES to analyze metals, and TOC to analyse the organic load. The number of the plants in this study equals around 50% of such installations in Finland subject to environmental permit as the IPPC directive provides. Results  EDTA, DTPA, and NTA were found in 11 samples out of 23 mainly in rather small concentrations. Their annual load to the receiving waters may be estimated to be 0.3 tons and the total load from Finnish ECST industry can be extrapolated to be up to 1 ton. Compared to the estimated use of 5–10 tons in the industry this finding is rather low, even though in Finland cast-off treatment baths are typically delivered to the hazardous waste treatment plants. Discussion  Since the load of complexing agents is rather low, the chemical waste water treatment seems to be either capable of reducing complexing agent concentrations to some extent or their usage is lower than expected. On the other hand, it is possible that not all complexing agents were identified from the samples. The metal concentrations and TOC were well hand in hand with concentrations found in the Finnish environmental database, which proves that the samples were of average quality of the waste water from the facilities. Conclusions  According to the results, complexing agents cannot be considered as an environmental risk in the ECST industry in Finland; EDTA concentrations are clearly below PNECaqua (2.2 mg/l) and the total discharge is very marginal compared to the discharge from the pulp and paper industry. However, DPTA seems to be as commonly used as EDTA, but also biodegradable NTA was found. Recommendations and Perspectives  Since EDTA has gained plenty of attention in the BREF, DTPA and other, poorly biodegradable complexing agents should also be taken into account when the BREF is updated within a few years. Also an EU risk assessment report especially for DTPA should be supplied, since its use is obviously increasing.  相似文献   
199.
Electrokinetic remediation of concrete: effect of chelating agents   总被引:1,自引:0,他引:1  
Contamination of concrete at various nuclear power plants and spent nuclear fuel reprocessing facilities by radionuclides represents a significant problem for the world's nuclear power industries and nuclear waste management. The present publication summarizes the most recently published data on Electrokinetic Remediation (EK) of various concrete installations and advantageous effects of the combination of EK with different chelating agents. The specific aspects of decontamination of concrete and mortar surfaces are analyzed, such as: (a) effect of chelating agents (EDTA, citric acid), (b) effect of the zeta-potential (zeta) of concrete surface, (c) effects of sorption and complex formation equilibrium, and (d) specific advantages and problems of the electrokinetic decontamination process. The results of laboratory and in situ tests of chelating agent assisted EK removal of radionuclides are reported. It is demonstrated that the correct combination of EK with specific chelating agents can be effectively employed for decontamination of concrete surfaces.  相似文献   
200.
以模拟含磷废水作为研究对象,研究不同工况条件下,复合微生物制剂、新型填料以及复合微生物制剂与新型填料结合对模拟含磷废水中磷的去除效果。实验结果表明:复合微生物制剂在曝气并且与新型填料结合的条件下对总磷的去除效率较高。对ρ(COD)<1 000 mg/L,ρ(TP)为15.34~20.96 mg/L的模拟含磷废水进行总磷的去除,其最佳工况参数为:复合微生物制剂投加量为0.2 g/L,pH值为9,曝气时间为48 h,反应时间为60 h。  相似文献   
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