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Effects on mixed microflora to enhance biohydrogen production from corn stover hydrolysate was studied. 相似文献
695.
Bisphenol A (BPA) is a chemical with high production volume and wide applications in many industries. Although BPA is known
as an endocrine disruptor, its toxic mechanisms have not been fully characterized. Due to its structural similarity to thyroid hormones
thyroxine (T4) and triiodothyronine (T3), one possible mechanism of BPA toxicity is disruption of hormone transport by competitive
binding with the transport proteins. In this study, the binding interactions of BPA, T4, and T3 with three thyroid hormone transport
proteins, human serum albumin (HSA), transthyretin (TTR), and thyroxine-binding globulin (TBG) were investigated by fluorescence
measurement. Using two site-specific fluorescence probes dansylamide and dansyl-L-proline, the binding constants of BPA with HSA
at drug site I and site II were determined as 2.90 104 and 3.14 104 L/mol, respectively. By monitoring the intrinsic fluorescence
of tryptophan, a binding constant of 4.70 103 L/mol was obtained. Similarly, by employing 8-anilino-1-naphthalenesulfonic acid as
fluorescence probe, the binding a nity of BPA with TTR and TBG was measured to be 3.10 105 and 5.90 105 L/mol, respectively.
In general, BPA showed lower binding a nity with the proteins than T3 did, and even lower a nity than T4. Using these binding
constants, the amount of BPA which would bind to the transport proteins in human plasma was estimated. These results suggest that
the concentrations of BPA commonly found in human plasma are probably not high enough to interfere with T4 transport. 相似文献
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Lihui Zhang Guomin Cao Yulei Fei Hong Ding Mei Sheng Yongdi Liu 《Frontiers of Environmental Science & Engineering in China》2011,5(4):604-609
A composite membrane bioreactor (CMBR) integrating the immobilized cell technique and the membrane separation technology was
developed for groundwater denitrification. The CMBR had two well mixed compartments with one filled with the nitrate-containing
influent and the other with a dilute ethanol solution; the compartments were separated by the composite membrane consisting
of a microporous membrane facing the influent and an immobilized cell membrane facing the ethanol solution. Nitrate and ethanol
molecules diffused from the respective compartments into the immobilized cell membrane where nitrate was reduced to gaseous
nitrogen by the denitrifying bacteria present there with ethanol as the carbon source. The microporous membrane was attached
to one side of the immobilized cell membrane for retention of the disaggregated bacteria. Relative to the single dose of external
ethanol, the two-dose supplementation produced better treatment results as evidenced by the lower concentrations of NO3−-N and ethanol (as measured by total organic carbon) of the effluent. The batch treatment in CMBR removed most of the nitrate
in the influent and attained a stable denitrification rate of 0.1 g·m−2·h−1 for most of the 96-h cycles during the 30-cycle study. The effluent was essentially free of ethanol and nitrite nitrogen. 相似文献
698.
地震灾害一直是人类社会所面临的重大自然灾害之一,在灾害发生之后,为了能够让灾区较短时间内恢复正常的生产生活和社会运行,高效率的恢复重建机制不可或缺.在所有的震后恢复重建项目中,灾区原有的工业企业的恢复重建是一大重点,这些工业企业在灾前往往是当地政府税收的主要来源,也为当地人口提供了大量的就业岗位.然而,能够投入到灾区用... 相似文献
699.
染整废水深度处理纳滤工艺膜污染成因分析 总被引:2,自引:1,他引:1
为调查棉针织染整废水纳滤脱盐系统膜污染的类型和成因,使用电感耦合等离子发射光谱仪、扫描电子显微镜-EDX能谱仪、傅里叶变换红外光谱仪、热重分析仪、高倍光学显微镜和X射线荧光光谱仪,从膜进水水质、膜过程污染状况和膜清洗效果等三方面进行了联合互补检测和综合分析.结果表明,棉针织染整废水脱盐过程中纳滤膜的污染类型包括无机污染、有机污染和微生物污染;干燥(105℃)的污染物成分组成中结合水所占质量分数约8.2%,有机成分所占质量分数约41.0%,无机成分所占质量分数约50.8%;在无机污染物中铁盐污染较为突出,有机污染物所包含的主要官能团为—OH、—CH和—CC,微生物污染物中包含原生动物和后生动物;短期膜污染和长期膜污染分析结果表明有机污染和微生物污染的形成需要长时间的累积效应;纳滤膜清洗试验结果表明,有机污染和微生物污染是引起膜通量下降的主要原因,两者对膜通量影响的贡献率约53.3%. 相似文献
700.
重点介绍了冶金企业包括瓦斯泥、瓦斯灰、转炉泥、选矿废渣、高炉矿渣、转炉钢渣在内的固体废弃物的基本特征以及对环境的污染情况。并对其有效元素回收和资源化利用提出建议。 相似文献