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印染废水问题形势依然严峻,目前常用生物法来治理,筛选高效降解染料的微生物是生物法处理印染废水的关键。本文利用梯度浓度压力驯化法,从印染废水水解酸化反应器中筛选出对染料活性黑5具有良好脱色性能的混合菌群DDMY1。利用该菌群在兼氧条件下对活性黑5进行脱色研究,首先采用拍照方式记录其反复脱色、复色的直观效果,其次运用紫外-可见光分光光度计检测其不同时间、不同状态下脱色液吸光值情况,最后运用气相色谱质谱联用仪和傅里叶变换红外光谱仪等检测方法分析脱色、复色过程中产物情况。结果表明,混合菌群DDMY1对活性黑5的脱色性能显著,24h脱色率能达到97.4%。同时,发现活性黑5的兼氧生物脱色反应可有效反复脱色、复色达17次之多,根据分析测试的结果,初步推测该现象可能是由活性黑5降解产物中的苯胺类物质或萘醌类物质造成的。 相似文献
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合成了1-(邻氯苯基)-3-(2-羟基苯基)-丙二酮(L1)、1-(间氯苯基)-3-(2-羟基苯基)-丙二酮(L2)和1-(对氯苯基)-3-(2-羟基苯基)-丙二酮(L3)3种配体,并将此3种配体分别与 Eu(III)反应生成3种新的稀土配合物。运用元素分析、红外光谱与荧光光谱等手段对配合物进行了表征。结果表明:3种配合物的组成分别为 Eu(L1)3·2H2O、Eu(L2)3·2H2O 和 Eu(L3)3·2H2O。荧光光谱显示,3种配合物的配体均能将吸收的能量有效地传递给三价铕离子,从而使配合物发射出强的铕离子的特征荧光。在3种配合物中,Eu(L1)3·2H2O 的荧光强度远大于 Eu(L2)3·2H2O 和 Eu(L3)3·2H2O 的荧光强度,这说明配体 L1与 Eu(III)离子的能级匹配较好,能量传递效率较高。 相似文献
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Preparation of Highly Pure n-3 PUFA-Enriched Triacylglycerols by Two-Step Enzymatic Reactions Combined with Molecular Distillation 下载免费PDF全文
Daoming Li Weifei Wang Xuehui Li Rabia Durrani Bo Yang Yonghua Wang 《Journal of the American Oil Chemists' Society》2017,94(2):225-233
Highly pure n-3 polyunsaturated fatty acids (PUFA)-enriched triacylglycerols (TAG) have attracted considerable attention due to their nutritional benefits and pharmacological effects. In this study, an alternative approach to the conventional method for the synthesis of highly pure n-3 PUFA-enriched TAG by using a multi-step process was reported. First, glyceride mixtures were synthesized through Novozym 435 [Novozymes A/S (Bagsvaerd, Denmark)] catalyzed esterification of n-3 PUFA-enriched FA and glycerol. Second, partial glycerides in the resulting glyceride mixtures were hydrolyzed to FA by immobilized partial glycerides-selective lipase from Malassezia globosa. The purity of TAG reached 99.84% under the optimized conditions: buffer solution of pH 6.0, water content of 100% (w/w, with respect to the oil mass), enzyme loading of 120 U/g (U/w, with respect to oil mass) and reaction temperature of 30 °C. During hydrolysis, the immobilized SMG1-F278N exhibited good reusability and TAG purity of over 94% was maintained after being used for six cycles. Subsequently, purification of TAG was accomplished by molecular distillation at low temperature (150 °C) and highly pure (99.85%) TAG with 88.73% n-3 PUFA was obtained. The final glyceride mixtures with low acid, peroxide and anisidine value were promising products for medical and dietetic purposes. Compared with the conventional one-step synthesis of n-3 PUFA-enriched TAG by enzymatic esterification or glycerolysis or the two-step method by combined transesterification and ethanolysis, this improved process allows for higher purity of n-3 PUFA-enriched TAG and significant reduction in reaction time. 相似文献
45.
Effect of methyl position on the dynamic mechanical and shape‐memory properties of cresol‐based polybenzoxazines 下载免费PDF全文
Three difunctional benzoxazines were synthesized from cresol isomers (o‐, m‐, and p‐methylphenols), 1,3‐bis(3‐aminopropyl)‐1,1,3,3‐tetramethyldisiloxane, and formaldehyde. The ring‐opening polymerization temperature decreases in the order of ortho‐, para‐, and meta‐positions of methyl group for the benzoxazine monomers, whereas the glass transition temperature increases in the order of ortho‐, para‐, and meta‐positions of methyl group for the resultant polybenzoxazines. In addition, the polybenzoxazines exhibit one‐way dual‐shape‐memory behavior in response to changes in temperature, and the shape‐memory effects are evaluated by tensile and bending tests with a temperature program based on glass transition temperature. The o‐ and p‐cresol‐based polybenzoxazines exhibit higher shape‐memory performance than their m‐cresol‐based analogue/counterpart. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45443. 相似文献
46.
A series of Zn–Ca–Al oxides with different CaO and ZnO contents have been prepared and evaluated in the synthesis of propylene carbonate(PC) from 1,2-propylene glycol(PG) and urea in a batch reactor. The effect of catalyst composition, basicity and reaction process parameters such as temperature, catalyst dose, molar ratio of PG to urea, purge gas flow and reaction time has been studied to find suitable reaction conditions for the PC synthesis. The PC selectivity and yield under the desired conditions could reach 98.4% and 90.8%, respectively. The best performing catalyst also exhibited a good reusability without appreciable loss in the PC selectivity and yield after five consecutive reaction runs. In addition, a stepwise reaction pathway involving a 2-hydroxypropyl carbamate intermediate was proposed for the urea alcoholysis to PC in the presence of Zn–Ca–Al catalysts, according to the time dependences of reaction intermediates and products. 相似文献
47.
In this study,HEA/AI composite interlayer was used to fabricate Ti/Mg bimetal composites by solidliquid compound casting process.The Al layer was prepared on the surface of TC4 alloy by hot dipping,and the FeCoNiCr HEA layer was prepared by magnetron sputtering onto the Al layer.The influence of the HEA layer thickness and pouring temperature on interface evolution was investigated based on SEM observation and thermodynamic analysis.Results indicate that the sluggish diffusion effect of HEA can ... 相似文献
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