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391.
Jen-Hao Chi Sheng-Hung WuJean-Claude Charpentier Yet-Pole IChi-Min Shu 《Journal of Loss Prevention in the Process Industries》2012,25(1):142-147
Hydrogen peroxide (H2O2), historically, due to its broad applications in the chemical industries, has caused many serious fires and explosions around the world. Its thermal hazards may also be incurred by an incompatible reaction with other chemicals, and a runaway reaction may be induced in the last stage. This study applied thermal analytical methods to explore the H2O2 leading to these accidents by incompatibility and to discuss what might be formed by the upset situations. Thermal hazard analysis contained a solvent, propanone (CH3COCH3, so-called acetone), which was deliberately selected to mix with H2O2 for investigating the degree of thermal hazard. Differential scanning calorimetry (DSC) and vent sizing package 2 (VSP2) were employed to evaluate the thermal hazard of H2O2. The results indicated that H2O2 is highly hazardous while mixed with propanone, as a potential contaminant. The time to maximum rate (TMR) was used as emergency response time in the chemical industries. Therefore, TMR of H2O2 was calculated to be 70 min for runaway reaction (after T0) and TMR of H2O2/propanone was discovered to be 27 min only. Fire and explosion hazards could be successfully lessened if the safety-related data are properly imbedded into manufacturing processes. 相似文献
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水环境中天然有机质会与砷形成络合物,进而影响砷的迁移、转化和生物毒性。研究利用超滤方法将腐殖酸(humic acid, HA)分为5个不同分子量的组分,以大型溞为受试生物,探究了不同分子量HA存在下砷对大型溞的毒性效应。结果表明,不同分子量的HA均缓解了As(Ⅲ)和As(Ⅴ)对大型溞的氧化应激损伤和细胞膜损伤,并降低了砷对MT的诱导量。其中1~30 k Da的HA对砷的缓解效果最好,1 k Da的HA毒性缓解效果最差,可能的原因是HA与砷的络合增加溶液中络合态砷的含量,而络合态砷难以进入细胞并被生物利用。不同分子量的HA对砷毒性的缓解差异与其跟砷的络合比例不同有关。 相似文献
396.
Gang Yi Xinfei Fan Xie Quan Shuo Chen Hongtao Yu 《Frontiers of Environmental Science & Engineering》2019,13(2):23
397.
Hang Zhang Shuo Chen Haiguang Zhang Xinfei Fan Cong Gao Hongtao Yu Xie Quan 《Frontiers of Environmental Science & Engineering》2019,13(2):18
398.
Nowadays, more people tend to spend their recreational time in large national parks, and trace metal(loid)s in soils have attracted long-term attention due to their possible harm to human health. To investigate the pollution levels, potential sources and health risks of trace metal(loid)s in road soils, a total of eight trace metal(loid)s (including As, Cd, Cr, Cu, Ni, Pb, Zn and Hg) from 47 soil samples along roads were studied in the Huangshan National Park in Southeast China. The results showed that the concentrations of As, Cd, Pb, Zn and Hg appeared different degrees of pollution compared with their corresponding background values. According to the pollution indices, Hg and Cd were recognized as significant pollutants presenting moderate to high ecological risk. Combining principal component analysis and positive matrix factorization model, the results showed that traffic, industrial, agricultural and natural sources were the potential origins of trace metal(loid)s in this area, with contribution rates of 39.93%, 25.92%, 10.53% and 23.62%, respectively. Non-carcinogenic risks were all negligible, while the carcinogenic risk of As was higher than the limit (1 10−6). Moreover, children were more susceptible to trace metal(loid)s by ingestion which appeared to be a more important exposure pathway than dermal contact and inhalation. The contribution rates of different sources to non-carcinogenic risks and carcinogenic risks were similar among children and adults, while traffic and industrial sources have a significant impact on health risks. This study will give more insights to control the environmental risks of trace metal(loid)s in national parks. 相似文献
399.
Zhang Xiuxiu Yi Guiyun Zhang Zhengting Yu Jia Fan Haiyang Li Peng Zeng Huihui Xing Baolin Chen Lunjian Zhang Chuanxiang 《Environmental science and pollution research international》2021,28(12):14671-14680
Environmental Science and Pollution Research - Due to the merits of their high adsorption and convenient separation, magnetic graphene-based composites have become a promising adsorbent in terms of... 相似文献
400.
利用NCEP逐6 h再分析资料、地面加密观测、探空、雷达资料,分析得出“利奇马”致灾暴雨是在长时间稳定维持的天气尺度环流背景下形成的。冷空气在降水所起的作用表现在:(1)长时间维持的弱冷空气与偏南暖湿气流交汇形成了边界层辐合线,辐射升温和暖湿气流的输送加大了辐合线两侧的温度和露点梯度,在高温高湿的有利环境下,对流在辐合线附近强烈发展。(2)高空槽后冷空气由“利奇马”环流西北侧渗入,先后形成3个冷平流中心,分别对应3个阶段的降水。(3)冷暖空气在降水区的持续辐合抬升作用增强了降水,最强降水时段发生在锋区垂直方向坡度最大的时段。(4)水平锋生有利于水汽输送和辐合抬升,垂直锋生有利于对流不稳定能量的累积和触发。冷空气形成的水平辐合和抬升造成大范围上升运动,使得锋生和垂直锋消同时存在,最强降水时段发生在水平锋生最强的时段。 相似文献