共查询到19条相似文献,搜索用时 171 毫秒
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介绍采用过滤、冷凝、吸附剂吸附三级串联的采样装置采集锅炉烟道气中多环芳烃和用超声提取、浓缩器浓缩、高压液相色谱分离、紫外-萤光检测器串联检测的实验方法。此法简单易行,适合于现场应用。 相似文献
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生物泥浆技术作为一种污染土壤生物修复技术,具有修复效率高、修复时间短及修复成本低等优点。本文介绍了生物泥浆修复设备的结构及修复工艺流程,例举了生物泥浆技术修复多环芳烃(PAHs)污染土壤的典型案例,探讨了生物泥浆技术修复PAHs污染土壤效果的主要影响因素:PAHs理化性质、PAHs污染浓度和污染时间、微生物、泥浆水土比、电子受体、传质过程等。展望了生物泥浆技术未来的发展方向:通过分子生物学工具监控、调节生物修复,促进泥浆内部微生物群落活动,有针对性地提高微生物对PAHs的修复能力。 相似文献
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本文讨论了用Seppak-C_(18)小柱(Waters.Co.)对水中痕量多环芳烃进行富集、洗脱的最佳实验条件,确定了用Zorbaxods柱分离PAH的色谱操作条件。应用紫外(250nm)和荧光(Ex/Em=295nm/427nm)检测器串联的检测系统,大大提高了PAH的检测下限。该方法用于实际水样的测定,其实验结果与用环巴烷萃取法测定结果基本相符。 相似文献
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《矿山资源开发利用与环境保护》2001,(1):18-20
自40年代美国洛杉矶市发生化学烟雾以来,世界上一些大城市也发生了光化学烟雾。我国在70年代末兰州西固地区也出现了光化学烟雾汽车排放的大量尾气是造成光化学烟雾的祸首,锅炉烟气也是重要的影响因素之一。各煤矿建立大型坑口电站,排放的SO2和NOx在煤矿周围易形成酸雨,破坏生态环境。更有甚者,如果电站周围地理位置和气候条件具备,极易出现硫酸烟雾和光化学烟雾事件。目前国内外对SO2的控制和治理做的工作较多,工艺也较成熟,而NOx的治理则显得落后。 相似文献
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This paper studies the fate of PAHs in full scale incinerators by analysing the concentration of the 16 EPA-PAHs in both the input waste and all the outputs of a full scale Fluidized Bed Combustor (FBC). Of the analysed waste inputs i.e. Waste Water Treatment (WWT) sludge, Refuse Derived Fuel (RDF) and Automotive Shredder Residue (ASR), RDF and ASR were the main PAH sources, with phenanthrene, fluoranthene and pyrene being the most important PAHs. In the flue gas sampled at the stack, naphthalene was the only predominant PAH, indicating that the PAHs in FBC’s combustion gas were newly formed and did not remain from the input waste. Of the other outputs, the boiler and fly ash contained no detectable levels of PAHs, whereas the flue gas cleaning residue contained only low concentrations of naphthalene, probably adsorbed from the flue gas. The PAH fingerprint of the bottom ash corresponded rather well to the PAH fingerprint of the RDF and ASR, indicating that the PAHs in this output, in contrast to the other outputs, were mainly remainders from the PAHs in the waste inputs. A PAH mass balance showed that the total PAH input/output ratio of the FBC ranged from about 100 to about 2600 depending on the waste input composition and the obtained combustion conditions. In all cases, the FBC was clearly a net PAH sink. 相似文献
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The polycyclic aromatic hydrocarbons (PAH) that contaminate soils at many industrial and government sites are resistant to natural biotic and abiotic degradation processes. The recalcitrant nature of these compounds may require aggressive chemical treatment to effectively remediate these sites. This study was conducted to assess the viability of permanganate oxidative treatment as a method to reduce PAH concentration in contaminated soils. Study results demonstrated a reduction in soil sorbed concentration for a mixture of six PAHs that included anthracene, benzo(a)pyrene, chrysene, fluoranthene, phenanthrene, and pyrene by potassium permanganate (KMnO4) oxidative treatment. The greatest reduction in soil concentration was observed for benzo(a)pyrene, pyrene, phenanthrene, and anthracene at 72.1, 64.2, 56.2, and 53.8%, respectively, in 30 min at a KMnO4 concentration of 160 mM. Minimal reductions in fluoranthene and chrysene concentration were observed at 13.4 and 7.8%, respectively, under the same conditions. A relative chemical reactivity order of benzo(a)pyrene>pyrene>phenanthrene>anthracene>fluoranthene>chrysene towards permanganate ion was observed. Aromatic sextet theory was applied to the degradation results to explain the highly variable and compound-specific chemical reactivity order. 相似文献
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采用索氏提取法和气相色谱分析了某炼油厂周边土壤中的多环芳烃的种类及含量,考察了6种有机溶剂对土壤中多环芳烃的浸取效果,探讨了溶剂与溶质溶解度参数差异对浸取效果的影响。结果表明:土壤试样中含有蒽、荧蒽、芘、 、苯并[a]蒽、苯并[b]荧蒽、苯并[k]荧蒽和苯并[a]芘8种多环芳烃,其含量分别为4.20,22.05,10.62,4.26,5.54,0.80,0.94,4.18 mg/kg;筛选出二氯甲烷作为土壤中多环芳烃的浸取溶剂;最佳浸取条件为浸取时间10 min、浸取温度30 ℃、溶剂与土壤的液固比5:1(mL/g)、土壤含水量8%,在此条件下,总多环芳烃浸出率为83.0%,各种多环芳烃的浸出率分别为蒽97.8%、荧蒽78.2%、芘99.9%、 98.5%、苯并[a]蒽81.1%、苯并[b]荧蒽47.6%、苯并[k]荧蒽14.8%、苯并[a]芘58.7%。 相似文献
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We have studied the availability and leaching of polycyclic aromatic hydrocarbons (PAHs) from two contaminated materials, a tar-containing asphalt granulate (Sigma16 US-EPA PAHs 3412mg/kg) and gasworks soil (SigmaPAHs 900mg/kg), by comparing results from three typical types of leaching tests: a column, sequential batch, and two different availability tests. The sequential batch test was found to largely resemble the column test. However, the leaching of particularly the larger PAHs (>5 aromatic rings) was found to be enhanced in the batch test by up to an order of magnitude, probably due to their association with large DOC (dissolved organic carbon) molecules generated by the vigorous mixing. The release of PAHs in the two availability tests, in which the leaching is facilitated by either a high concentration of DOC or Tenax resin, was similar, although the latter test was easier to perform and yielded more repeatable results. The availability was much higher than the amount leached in the column and sequential batch tests. However, biodegradation had apparently occurred in the column test and the total amount of PAHs released by either leaching or biodegradation, 9% and 26% for asphalt granulate and gasworks soil, respectively, did equal the amount leached in the availability tests. Therefore, the availability was found to provide a relevant measure of the PAH fraction that can be released from the solid phase. These results stress the importance of using the available instead of the total amount of contaminant in the risk analysis of solid materials in utilization or disposal. 相似文献
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烟气脱硝技术的研究 总被引:12,自引:0,他引:12
氮氧化物(NOx)的污染危害是一个不容忽视的问题.目前,我国燃煤电厂排放烟气的SO2治理已逐步走向正轨,新建的燃煤电厂基本都安装效率较高的脱硫装置.因此,控制NOx的排放将是下一步的主要任务.对选择性催化还原法(SCR)、非选择性催化还原法(SNCR)、电子束或电晕放电脱硝法、光催化氧化法等烟气中NOx控制技术的机理、现状、发展趋势和主要优缺点进行了详尽的论述.通过对各种工艺技术的脱除效率、应用条件、经济性等方面的分析、比较和总结,提出了未来脱硝技术研究工作的重点.基于我国的实际情况提出了烟气脱硝的可行方案,从而为工业废气脱硝技术的进一步开发和研究提供参考. 相似文献
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Asphalt products, particularly sealants, are prepared using petroleum products that contain a com‐plex mixture of aliphatic and aromatic hydrocarbons, including polycyclic aromatic hydrocarbons (PAHs). Clearly, these products are ubiquitous in urban environments, which raises an issue regard‐ing the potential for PAHs to be transported from parking lots to underlying or adjacent soil, surface‐water bodies, or groundwater. Based on a literature review, there are limited studies focus‐ing on this issue; however, the studies that have been published have fascinating conclusions. The literature shows, as expected, that asphalt‐based products contain PAHs. The highest PAH concen‐trations are present in asphalt sealants, particularly those manufactured using coal tar. Furthermore, due to the low solubility and high partition coefficients of PAHs, the potential for PAHs to leach from asphalt surfaces is negligible, which has been confirmed by leachability studies. Thus, there is little risk that PAHs will be present in stormwater runoff or leach into groundwater from asphalt‐paved areas in a dissolved form. However, asphalt pavement and sealants produce particulate matter that can contain concentrations of PAHs in the sub‐percent range (100s to 1,000s mg/kg total PAHs) that is transported in stormwater runoff. Some studies show that this can cause soil and sediment con‐tamination with total PAH concentrations in the range of 1 to 10 mg/kg. From a remediation per‐spective, many site cleanups are conducted to remediate the presence of PAHs to cleanup goals below 1 mg/kg or, in some cases, 0.1 mg/kg or lower. From a total risk perspective, remediating sites to low PAH cleanup goals may be unwarranted in light of the risk of transportable PAHs produced from paved parking surfaces. In other words, is it reasonable to conduct a cleanup to remediate low PAH concentrations and then redevelop the area with asphalt pavement and sealant, which may pose a greater PAH‐related risk? © 2006 Wiley Periodicals, Inc. 相似文献
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利用活性炭固定床吸附分离表面活性剂和多环芳烃(PAH)的混合溶液,选取了具代表性的表面活性剂(TX100)和PAH(菲(PHE)等)。实验结果表明,流量越低、活性炭填充量越多、表面活性剂浓度越高、PAH浓度越低,越有利于表面活性剂的回收和PAH的去除。定义了有效回收时间,该时间是指PAH穿透10%的时间与表面活性剂穿透90%的时间之差,该时间越长,越有利于表面活性剂的回收。采用BDST和Thomas模型对TX100和PHE进行了吸附模拟,效果均较好;BDST模型拟合结果表明,当活性炭对TX100的吸附接近饱和时仍对PHE有较强的吸附能力。活性炭固定床吸附分离法可节约运行成本0.06元/L。 相似文献