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21.
Hiroyasu Yamazaki Masayuki Terada Akira Tsuboi Chizuyo Matsubara Toshiaki Hata Yasuo Kakiuchi 《毒物与环境化学》2013,95(1-2):71-81
Orally administered 3H‐benzo(a)pyrene (BP) was persistent in protein fraction of liver, lung and kidney. The radioactivity in this fraction increased with time after administration and accounted for about 50%, 40% and 65% of total radioactivity in liver, lung and kidney, respectively at 48 hr. The BP metabolites binding proteins were located in cytosol and had molecular weights of 40,000–60,000 and 80,000–100,000 as determined by gel filtration and polyacrylamide gel disc electrophoresis. In addition, at 48hr after administration, about 80% of radioactivity in high molecular weight protein fraction was found to be precipitated by trichloroacetic acid treatment. These results suggest that BP metabolites might be transported by and are persistent in these protein fractions of liver, lung and kidney if the intake of BP is continuous. These proteins, therefore, appeared to be closely related to cell toxicity or mutagenicity in these organs as well as DNA. 相似文献
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S. D. Worley H. D. Burkett J. F. Price 《Journal of the American Water Resources Association》1984,20(3):369-371
A new organic N-chloramine disinfectant (3-chloro-4, 4-dimethyl-2-oxazolidinone, agent I) has been compared with calcium hypochlorite as to its tendency to react with organic matter in water to produce toxic trihalomethanes. Agent I reacts much less readily with organic demand than does calcium hypochlorite. This study shows that agent I should be safe to use as a disinfectant for water containing appreciable organic load in either sunlight or darkness. On the other hand, calcium hypochlorite may not be a satisfactory disinfectant from the toxicity standpoint for water which contains organic load which must be stored for extended time periods in either sunlight or darkness. 相似文献
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Zhimin QIANG Weiwei BEN ChinPao HUANG 《Frontiers of Environmental Science & Engineering in China》2008,2(4):397-409
The degradation of selected chlorinated aliphatic hydrocarbons (CAHs) exemplified by trichloroethylene (TCE), 1,1-dichloroethylene
(DCE), and chloroform (CF) was investigated with Fenton oxidation process. The results indicate that the degradation rate
was primarily affected by the chemical structures of organic contaminants. Hydroxyl radicals (·OH) preferred to attack the
organic contaminants with an electron-rich structure such as chlorinated alkenes (i.e., TCE and DCE). The dosing mode of Fenton’s
reagent, particularly of Fe2+, significantly affected the degradation efficiency of studied organic compound. A new “time-squared” kinetic model, C = C
o
exp(−k
obs
t
2), was developed to express the degradation kinetics of selected CAHs. This model was applicable to TCE and DCE, but inapplicable
to CF due to their varied reaction rate constants towards ?OH. Chloride release was monitored to examine the degree of dechlorination
during the oxidation of selected CAHs. TCE was more easily dechlorinated thanDCE and CF.Dichloroacetic acid (DCAA) was identified
as the major reaction intermediate in the oxidation of TCE, which could be completely removed as the reaction proceeded. No
reaction intermediates or byproducts were identified in the oxidation of DCE and CF. Based on the identified intermediate,
the reaction mechanism of TCE with Fenton’s reagent was proposed. 相似文献
26.
黄志强 《中国环境管理干部学院学报》2013,(4):64-67
采用真空采血管顶空填充柱气相色谱法测定水中三氯甲烷和四氯化碳,结果表明,三氯甲烷在10.0~50.0μg/L,四氯化碳在0.5~4.0μg/L浓度范围内呈良好线性关系,其r值分别为0.9994和0.9998;三氯甲烷和四氯化碳RSD分别在1.64%~2.27%和1.45%~2.40%之间;加标回收率分别在97.0%~103.5%和94.0%~103.2%之间。该方法操作简单,具有较好的灵敏度和准确度,适用于水中三氯甲烷和四氯化碳的检测。 相似文献
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Risk Analysis of Volatile Organic Compounds Through Daily Life Cycle in the Industrial City in Korea
This study analyzed the risk of exposure to volatile organic compounds (VOCs) through a study of activity patterns in the Korean industrial city, Ulsan. The daily life cycle patterns(LCPs) of 331 people in Ulsan were surveyed and the average LCPs in Ulsan were obtained by statistical analysis. Nine to twelve personal air samples of VOC exposure at the breathing zones were collected at each LCP. This included hours for sleeping,cooking and eating, going to and from work, working, participating in field or outdoor activities, reading, watchingTV, and shopping. The components and concentrations of the collected VOCs were identified by a Gas Chromatography-MassDetector (GC-MS). The overall reproducibility of all GC analytical procedures of the simultaneously collected duplicatesample pairs represented a mean of percent differences rangingfrom about 9 to 13%. For the general population of Ulsan, thecarcinogenic and non-carcinogenic risk of exposure to theVOCs during the LCPs was evaluated. The carcinogenic riskwas analyzed using both the chronic daily exposure orlifetime average daily exposure (CDI) and the cancerpotency factor. The non-carcinogenic risk was analyzedusing both the CDI and the chronic reference dose.The major chemical forms of the identified VOCs were oxidized forms (43%), aliphatic alkanes (29%) and aromatics (15%). Even though the highest total exposure strength per unit time of each activity was observed during shopping, the highest totalamount of exposure to VOCs was identified as the exposure duringwork. The total carcinogenic risk of exposure to the carcinogenicVOCs through daily life cycle in Ulsan was 2.0 × 10-4which is substantially exceeding the permissible carcinogenicrisk level, 10-5 10-6. The carcinogenic riskduring most of the life cycle activities, except forreading, mainly performed indoors, was higher than that ofthe activities performed outdoors. The carcinogenic risk bybenzene exposure was about 56% (time weighted average) ofthe total carcinogenic risk by the exposure to thecarcinogenic VOCs. During cooking and eating, shopping andout door activities, however, the carcinogenic risk by theexposure to chlorinated compounds like chloroform exceededthe exposure to benzene. The overall hazard index (non-carcinogenic risk) by a chronic exposure to carcinogenicand non-carcinogenic VOCs through daily life cycle in Ulsanwas evaluated as 3.91 × 10-1, which is much less than1.0 considered as a hazard level to human health, and thusit seems likely not to produce a severe health hazard. 相似文献
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酸性体系中Pd/PPy/foam-Ni电极电化学还原三氯甲烷 总被引:2,自引:0,他引:2
在沉积电流密度5 mA·cm-2,沉积时间40 min条件下,通过电沉积方法制备Pd/PPy/泡沫镍(foam-Ni)电极,以Pd/PPy/foam-Ni电极为阴极研究酸性体系中三氯甲烷的电化学还原脱氯,实验在室温条件下进行.采用循环伏安法对电极进行测试,Pd/PPy/foam-Ni电极在-500 mV (vs Hg/Hg2SO4)左右获得很大的氢吸附峰电流值,峰电流值为-100 mA.扫描电镜(SEM)分析表明,聚吡咯的引入改变了Pd在电极表面的沉积形态,使电极表面具有很好的空间延伸性.在酸性体系中进行Pd/PPy/foam-Ni电极对三氯甲烷的电化学还原脱氯实验,结果表明,综合考虑三氯甲烷去除率及脱氯过程电流效率,在保证脱氯过程电流效率为44.17%的条件下,三氯甲烷的去除率为49.23%,此时最佳脱氯电流密度为0.05 mA·cm-2,最佳脱氯时间为180 min,实现了在酸性水溶液体系中,低初始浓度三氯甲烷较好的脱氯效果. 相似文献
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主要研究了不同pH值对高氨氮垃圾渗滤液的电化学氧化的影响,重点考察了pH值在电解过程中的电解速率、电流效率、能耗以及三氯甲烷生成情况。结果表明:pH对电化学氧化垃圾渗滤液过程有重要的影响。在弱碱性条件下,电解垃圾渗滤液过程中氨氮及COD的降解速率、电流效率及能耗均要比在强酸、强碱条件下高,当pH为8.09时,经过6 h降解,氨氮的去除率达到100%,氨氮的降解速率为7 mg/(L.min),电流效率为45.23%,氨氮能耗为0.09kWh/g,COD的降解去除率达到50%,三氯甲烷产生的随着电解时间的增加而增加,电解6 h后三氯甲烷浓度从低于检测值升高至0.636 mg/L。 相似文献
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研究三氯甲烷在单独超声(US)、单独零价铁(Fe0)及超声波/零价铁协同体系(US/Fe0)中的降解发现,拟一级动力学能很好地拟合降解过程,协同体系中三氯甲烷一级降解速率常数(KUS/Fe0)为0.010 3 min-1,约为同等条件下零价铁体系所得KFe0的3倍,且大于KFe0与KUS之和,说明二者之间存在协同效应.考察零价铁投加量〔ρ(Fe0)〕,初始pH,初始三氯甲烷浓度(c0),超声功率,溶液离子强度等控制参数对三氯甲烷降解速率(KUS/Fe0)的影响,结果表明,其拟一级速率常数分别在ρ(Fe0)为6 g/L,初始pH为6.0,c0为5 mmol/L以及0.5 mol/L Na2SO4当量离子强度下达最大值,并且随着超声功率的增大而增大. 相似文献