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991.
Occurrence, distribution and bioaccumulation of antibiotics in the Haihe River in China 总被引:1,自引:0,他引:1
The occurrence, distribution and bioaccumulation of 22 antibiotics, including eight fluoroquinolones (FQs), nine sulfonamides (SAs) and five macrolides (MLs), in the Haihe River were investigated. Surface water, sediment and fish samples were analyzed by HPLC-MS/MS. Ofloxacin, sulfamethoxazole, sulfadiazine, erythromycin and roxithromycin were found in all surface water samples. SAs were the predominant antibiotics in surface water samples in the mainstream of Haihe River, with the maximum concentration of 201 ng L(-1) for sulfamethoxazole. Compared with Haihe River, higher concentrations of antibiotics were found in the surface water samples in the Dagu and Chentaizi Drainage Rivers. The antibiotics pollution in the mainstream of Haihe River may derive from its tributaries, whereas the wastewater from fish ponds was not the main source of FQs, SAs and MLs in the river water. In sediment samples, FQs were the most frequently detected antibiotics and their concentrations were much higher than SAs and MLs. The high concentrations and detection frequencies of FQs in sediments indicate that sediments are an important reservoir for FQs as they are strongly adsorbed onto sediments. Ciprofloxacin and erythromycin exhibited potential bioaccumulation in crucian carp, with mean bioaccumulation factors of 3262 L kg(-1) and 4492 L kg(-1), respectively. 相似文献
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Guorui Liu Minghui Zheng Mingwei Cai Zhiqiang Nie Bing Zhang Wenbin Liu Bing Du Shujun Dong Jicheng Hu Ke Xiao 《Chemosphere》2013,90(9):2453-2460
In this study, field measurements were conducted to estimate and characterize the atmospheric emission levels and profiles of polychlorinated biphenyls (PCBs) from multiple industrial thermal processes. The emission levels and profiles of PCBs from five types of thermal processes at twenty-three plants were studied and compared with eight processes reported in our previous studies. Correlation analysis was preformed to identify a marker congener for emission of ΣPCB. A significant correlation was observed between congener CB-118 and ΣPCB (R2 = 0.65 and p < 0.01), which suggests that CB-118 is a good marker congener for emission of ΣPCB. The profiles of PCBs emitted from the thirteen thermal processes were compared, and this information could be used for studying source–receptor relationships and identifying the specific sources of PCBs. To prioritize the sources for control, the concentrations of PCBs from thirteen industrial thermal sources were compared. The PCB concentrations from secondary zinc smelting and thermal wire reclamation were about one to three order magnitude higher than those of other sources, which suggests that these two sources be given priority in PCB source control. Finally, the atmospheric emission factors of PCBs from the thirteen industrial sources were summarized, and these data will be useful for developing an integrated emission inventory of PCBs. 相似文献
995.
以废旧线路板真空热解油为原料,NaOH为催化剂,与甲醛的缩聚反应合成热固性酚醛树脂(TPR),重点考察了合成条件对产物固含量的影响。结果表明,合成热固性酚醛树脂的最佳条件为:每38.5 g热解油加入甲醛、催化剂分别为40 g、10 g,第1阶段温度为60℃、反应时间为3 h,第2阶段温度为95℃、反应时间按为3 h,其中催化剂的加入量是最主要的影响因素。通过红外光谱分析(IR)及热重分析(TG)测定了合成产物的结构和性能,并对产物进行了力学性能的检测。结果证明,以热解油为原料合成的酚醛树脂出现了CH2、CH—OH等特征峰,且产物的耐热温度在300℃以上,拉伸强度达到了39.6 MPa,与以苯酚为原料合成的酚醛树脂相近,研究结果表明,真空热加油为原料合成酚醛树脂是可行的。 相似文献
996.
完全自营养脱氮过程中的影响因素 总被引:1,自引:0,他引:1
基于正交实验考察了溶解氧(DO)、初始NH4+-N浓度、pH对SBR自营养脱氮性能的影响。结果表明,DO和NH4+-N浓度对好氧氨氧化速率影响大,pH对好氧氨氧化速率的影响小;DO、NH4+-N浓度对亚硝酸氧化速率的影响较大,pH对亚硝酸氧化速率的影响较小;DO、NH4+-N浓度和pH对厌氧氨氧化菌(ANAOB)的活性影响较小。好氧氨氧化菌(AOB)直接影响到CANON系统的总氮去除能力,是CANON系统的控制反应,DO是关键控制因子。实验确定的CANON系统优化运行条件为,DO(0.3±0.05)mg/L、初始NH4+-N浓度150mg/L和pH7.4。 相似文献
997.
Occupational exposure to synthetic musks in barbershops,compared with the common exposure in the dormitories and households 总被引:1,自引:0,他引:1
Synthetic musks (SMs) have been widely used as fragrance ingredients in personal care and sanitary commodities. Due to their high volatility and particle-binding affinity, the indoor dust is a major reservoir of SMs, and dust ingestion could be an important exposure way to special populations, such as hairdressers. In spite of the known toxicity of SMs, there is no information regarding the occurrence of SMs in barbershop dusts and the exposure of hairdressers through indoor dust ingestion. In the present study, the levels of two nitro musks and five polycyclic musks were measured from indoor dust samples collected from barbershops, and some other indoor dust samples were also collected from dormitories, bathhouses and households for comparison. The concentrations of ∑SMs in barbershop dusts were 10–100 times higher than those from the other three indoor microenvironments. Polycyclic musks accounted for 89.4% of ∑SMs on average in all samples, of which two compounds, HHCB and AHTN jointly dominated 97.9% of polycyclic musks. The levels of HHCB and AHTN varied from 12.2 to 8.39 × 105 and from 13.2 to 3.49 × 105 ng g−1, respectively. The daily intakes (DIs) of ∑SMs through house dust ingestion were estimated using the model of high dust ingestion and worst-case exposure (P95), and the corresponding exposure rates were 2791, 135 and 727 ng d−1 for the hairdressers, general population and toddlers. SMs were also detected in blood samples collected from the hairdressers and normal adults (n = 50 and 10, respectively). There was no significant difference between these two groups. Despite the absence of higher SM concentrations in hairdresser’s blood, we should not overlook the potential occupational health risks due to their high SMs ingestion rate. 相似文献
998.
自焙阳极铝电解槽在生产过程中产生的大量有害气体和粉尘 ,在我国至今没有一种有效的治理方法。我院首次应用电除尘与静电凝聚技术相结合 ,净化自焙阳极铝电解槽生产过程中所产生的有害气体和烟尘获得成功。经国家环保部门测试认定 ,其沥青烟、氟化物和粉尘的排放量均低于国家排放标准。该项技术为我国铝电解行业消除对环境的污染提供了一种最佳的治理方法。介绍了净化工艺原理、实施方法、技术效果与现场运行实测数据 相似文献
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运用系统科学理论对安全状态评价模型构模原理进行阐述;根据评价系统状态的模糊性特征,结合人们对安全状态的认识、理解和接受方式,提出了评价系统状态程度与状态存在的可能性多值表达方法 相似文献