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981.
嗜盐菌与高盐度废水生物处理研究进展 总被引:2,自引:0,他引:2
嗜盐菌指在高盐环境下生长的细菌,它主要生长在盐湖、盐场等浓缩海水中,以及腌鱼、盐兽皮等盐制品上。本文简要介绍了嗜盐菌的分类、形态特征和嗜盐机理。国内外学者采用了不同的工艺研究了高盐度废水生化处理的可行性,研究得出盐度对生物处理系统存在不同的影响,本文综述了盐度对生物处理系统有机物去除率和脱氮除磷效果的影响以及在污泥驯化过程中微生物相、优势菌种和污泥沉降性能的变化;总结了嗜盐菌在高盐度废水生物处理中的应用,为这方面的进一步研究提供参考。 相似文献
982.
A self-design bioreactor system employing a fixed bed operation process with immobilized Bacillus subtilis AYC beads for NH4
+-N
removal from slightly polluted water was proposed. Polyvinyl alcohol and Na-alginate were used as a gel matrix to entrap Bacillus
subtilis AYC to form the immobilized beads. The NH4
+-N removal process was studied in a intermittent operation mode to examine
the start-up and steady state behaviors of the immobilized AYC in the reactor. The results indicated that the reactor was in the start-up
state during the first week. NH4
+-N began to be steadily removal since the second week, and the nitrogen removal rate was between
84.61% and 96.19% when the hydraulic retention time (HRT) was 30 min. To apply Bacillus subtilis AYC to develop a practical
nitrogen removal system and further understand its nitrogen removal ability, the bioreactor was continuously operated under different
experimental perameters. The results showed that under the optimum conditions of an HRT of 20 min and DO of 3.77–5.80 mg/L,
the NH4
+-N removal rate reached 99.55%. The NH4
+-N removal rate increased as the C/N ratio increased. However, a high C/N may
cause a high residual carbon level in the effluent, therefore, the most suitable C/N ratio was 10. In addition, the results showed that
the bioreactor system could remove many types of nitrogen such as NH4
+-N, NO3??-N and organic-N, and had a good performance for
inorganic nitrogen removal from sewage. 相似文献
983.
984.
利用金相分析、电镜、岛津材料试验机等方法研究了不同净化工艺对镁合金力学性能、组织、断口形貌的影响。结果表明 ,对于AZ91镁合金 ,精炼剂的用量不宜超过 3 .5 % ,浇注温度应控制在 72 0~ 730℃。采用熔剂、吹氩和过滤的复合净化处理工艺可以有效清除镁熔体中的夹杂物和气孔 ,使镁合金的性能得到极大的提高。经复合净化处理后的AZ91的σb和δ可分别达到 2 0 6 .1MPa和 5 .2 1 %。金相观察表明 ,净化处理对金相组织无明显的影响 ,不改变AZ91镁合金的断裂机理 ,断口均成准解理断裂 相似文献
985.
986.
987.
988.
IntroductionThecombustionoffossilfuelsgeneratesSO2 andNOxpollutantswhichcauseairpollutionandacidrain .Existingfluegasdesulfurization(FGD)scrubbersinvolvelimestoneprocesses,whichareefficientforcontrollingSO2 emission ,butareincapableofremovingalmostwater i… 相似文献
989.
990.
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