皮革化学品可生物降解性及其构-效关系研究

介绍了化学品可生物降解的定义及意义,化学品生物降解的作用机理,化学品定量结构-生物降解性关系(QSBR)以及化学品可生物降解性的一般研究方法和预测方法,并对其它降解方法也进行了简介。最后对易于生物降解化学品结构特点进行了总结,在此基础上,对可生物降解皮革化学品的研究趋势做出了展望。     

皮革生物降解性的评价

皮革行业可持续性的发展,首先必须面对的便是废弃皮革产生的生态问题。因而研究皮革可生物降解性很有必要,以便生产出生物降解性良好的皮革,使其稳定性和生物降解性达到一种平衡状态。针对这个目的,本文主要论述了目前国内外对皮革生物降解规律与机理的研究进展,介绍了评价皮革生物降解性的方法,最后从环境保护的角度出发,对皮革生物降解性...     

化学品生物降解的评价方法

本文介绍了化学品生物降解的定义、化学品在微生物中的曝露实验的方法,总结了有机物好氧生物降解和厌氧生物降解的评价方法。最后介绍了难于生物降解的“三致”型(致癌、致畸、致突变)有机污染物的降解方法,为污染物的降解提供了参考。     

纺织材料可生物降解性评价方法的研究概述

近年来,可生物降解的高分子材料的研究多集中于塑料材料,并且已经建立了比较完善的塑料材料可生物降解性评价方法与标准体系,而对于纺织材料尤其是合成纤维的可生物降解性评价还缺乏系统的研究。本文在分析现有可生物降解性评价标准及评价方法的基础上,就纺织材料可生物降解性评价方法的研究情况作了系统的介绍,最后介绍了各主要市场对可生物降解及可堆肥的要求。     

黑液中木素生物降解性能的研究

针对木素难生物降解的特点，研究了木素在普通活性污泥中的生物降解性能，并探讨环境因素如ｐＨ、时间、污泥接种量及营养物质的种类及数量对木素生物降解的影响。研究环境因素的改进对木素生物降解性能产生的影响，如活性污泥的驯化、培养基的改良所产生的效果。同时还研究了微生物在厌氧及好氧条件下对木素生物降解产生的影响。     

纺织材料生物降解性能及标准研究进展

塑料的可生物降解标准和评价方法相对完善,研究比较深入。而针对纺织材料的生物降解研究比较薄弱,并且没有相应的检测标准和评价方式。该文归纳总结了现有可生物降解的测试方法和评价体系,简述目前纺织材料可生物降解研究的进展,并通过分析比较纺织材料采用可生物降解的方法,试图找出最适合纺织材料可生物降解的方法。     

表面活性剂的生物降解性研究进展

介绍了表面活性剂生物降解的一般规律;表面活性剂生物降解性的影响因素;详细阐述了阴离子表面活性剂、阳离子表面活性剂、两性表面活性剂、非离子表面活性剂、新型表面活性剂生物降解机理及其结构与生物降解性的关系;最后,对表面活性剂发展趋势进行了展望。     

表面活性剂的生物降解性研究进展

介绍了表面活性剂生物降解的一般规律;表面活性剂生物降解性的影响因素;详细阐述了阴离子表面活性剂、阳离子表面活性剂、两性表面活性剂、非离子表面活性剂、新型表面活性剂生物降解机理及其结构与生物降解性的关系;最后,对表面活性剂发展趋势进行了展望.     

国际羊毛局《超细纤维污染和羊毛的海洋生物降解》报告

通过将两种美丽诺羊毛在海水中的生物降解能力与人造丝、涤纶、尼龙和丙纶的生物降解能力进行比较,报告发现,未经处理的羊毛和可机洗的羊毛(降解速度较未处理羊毛更快)在海洋环境中均易于生物降解,不会增加海洋中的微塑性污染,但合成纤维则不然。将这些纤维的生物降解速率与已知易于生物降解的牛皮纸纸浆进行比较,科学家发现,未经处理的羊毛的生物降解率是纸浆的20.3%,而可机洗的羊毛的生物降解速度提高了3倍以上,达到了纸浆的67.3%,是实验中所有织物中最快的。     

大豆蛋白可生物降解材料的研究现状

本文阐述了可生物降解材料的概念及其降解机理,介绍了大豆蛋白可生物降解材料的制备方法,综述了大豆蛋白可生物降解材料的研究现状,并对存在的问题和应用前景进行了分析。     

生物可降解非织造布

本文讨论了生物可降解非织造布的降解原理 ,介绍了用于生产生物可降解非织造布的原料 ,生物可降解非织造布的加工工艺。文中指出 ,生物可降解非织造布具有优良的性能 ,广泛用于医疗、衣着、工业、农业、土木工程和日常生活中。生物可降解非织造布的应用对环保意义重大。     

三氯氧磷交联淀粉的生物降解性能研究

利用微生物在半生物体内模型中系统研究了三氯氧磷交联淀粉的生物降解性能。结果表明，淀粉经三氯氧磷交联化后，其微生物降解的速度和程度随交联度的提高而降低。低程度的交联可促进淀粉的微生物降解速度和程度，而高交联对淀粉的微生物降解却起到抑制作用。通过控制三氯氧磷交联淀粉的交联度可以调解淀粉的微生物降解速度和降解程度。     

三氯氧磷交联淀粉生物降解过程中形貌和结晶结构的变化

利用扫描电子显微技术和多功能偏光显微技术系统研究三氯氧磷交联淀粉在生物降解过程中的颗粒形貌和结晶结构变化情况.结果表明：随着交联度的增大,颗粒被微生物破坏的程度变小.经三氯氧磷高交联后的木薯淀粉在微生物降解过程中颗粒的偏光十字变化不明显,表明一定程度的三氯氧磷交联会抑制微生物对淀粉颗粒的作用.     

Applicability of stable isotope fractionation analysis for the characterization of benzene biodegradation in a BTEX-contaminated aquifer

In recent years the analysis of stable isotope fractionation has increasingly been used for characterizing and quantifying biodegradation of contaminants in aquifers. The correlation of carbon and hydrogen isotope signatures of benzene in a BTEX-contaminated aquifer located in the area of a former hydrogenation plant gave indications that biodegradation mainly occurred under anoxic conditions. This finding was consistent with the investigation of hydrogeochemical conditions within the aquifer. Furthermore, the biodegradation of benzene was calculated by changes in carbon isotope signatures using the Rayleigh-equation-streamline approach. Since contaminant concentrations can be also affected by nonisotope-fractionating abiotic processes such as dilution, volatilization, or irreversible sorption to the aquifer matrix, the Rayleigh-equation-streamline approach was adjusted for scenarios assuming that biodegradation and abiotic processes occur either consecutively or simultaneously along a groundwater flow path between contaminant source and sampling well. The results of the scenarios differed significantly, indicating that an abiotic process (typically dilution) causes a decrease in benzene concentration within the investigated aquifer transect. This comparison of results derived from the different scenarios can help to identify whether biodegradation is the predominant process for decrease in contaminant concentration. However, for a proper quantification of biodegradation, the temporal sequence between biodegradation and dilution needs to be known. The uncertainty associated with the quantification of pollutant biodegradation by the Rayleigh-equation-streamline approach increases when nonisotope-fractionating abiotic processes cause a significant decrease in contaminant concentrations.     

Determining the extent of biodegradation of fuels using the diastereomers of acyclic isoprenoids

Improved testing and remediation procedures for sites contaminated with petroleum hydrocarbons are a priority in remote cold regions such as Antarctica, where costs are higher and remediation times are longer. Isoprenoid/n-alkane ratios are commonly used to determine the extent of biodegradation at low levels but are not useful once the n-alkanes have been removed. This study demonstrates how the diastereomers of the acyclic isoprenoids can be used to determine the extent of biodegradation in moderately biodegraded fuel in soils from a bioremediation trial at Casey Station, Antarctica. The biological diastereomers of pristane (meso; RS = SR) are depleted more rapidly during moderate biodegradation than the geological or mature diastereomers (RR and SS), and thus, the ratio of pristane diastereomers can determine the level of biodegradation. The statistical difference among mean diastereomer ratios for samples grouped according to the biodegradation scale and pristane/phytane ratios was highly significant. The ratios of norpristane and phytane diastereomers also change with biodegradation in a similar fashion, and different levels of sensitivity exist for each. Additional benefits are that the method can be performed on conventional gas chromatographs by non-specialist chemists and that the ratios are independent of evaporation and do not necessarily require a non-biodegraded reference (T0) sample. This study details a simple alternative method for determining the extent of biodegradation of fuels at moderate levels that can be applied to a wide range of petroleum products.     

Hydrogen isotopic enrichment: an indicator of biodegradation at a petroleum hydrocarbon contaminated field site

Compound-specific carbon and hydrogen isotope analysis was used to investigate biodegradation of benzene and ethylbenzene in contaminated groundwater at Dow Benelux BV industrial site. delta13C values for dissolved benzene and ethylbenzene in downgradient samples were enriched by up to 2+/-0.5 per thousand, in 13C, compared to the delta13C value of the source area samples. delta2H values for dissolved benzene and ethylbenzene in downgradient samples exhibited larger isotopic enrichments of up to 27+/-5 per thousand for benzene and up to 50+/-5 per thousand for ethylbenzene relative to the source area. The observed carbon and hydrogen isotopic fractionation in downgradient samples provides evidence of biodegradation of both benzene and ethylbenzene within the study area at Dow Benelux BV. The estimated extents of biodegradation of benzene derived from carbon and hydrogen isotopic compositions for each sample are in agreement, supporting the conclusion that biodegradation is the primary control on the observed differences in carbon and hydrogen isotope values. Combined carbon and hydrogen isotope analyses provides the ability to compare biodegradation in the field based on two different parameters, and hence provides a stronger basis for assessment of biodegradation of petroleum hydrocarbon contaminants.     

Biodegradation of caffeine: Formation of theophylline and theobromine from caffeine in mature Coffea arabica fruits

The level of theophylline in mature and ripened fruit is 20–50 times that in the immature green fruit of Coffea arabica L. Biodegradation of caffeine occurs in the mature, ripened coffee fruits through theophylline and theobromine as the first biodegradation products. It is now clear that theophylline is associated primarily with caffeine biodegradation, whereas theobromine is involved in both biosynthesis and biodegradation of caffeine.     

生物降解柠檬酸及其影响因素的研究进展

柠檬酸(citric acid,CA)是一种天然的有机酸,在成熟的柠檬、百香果、红树莓等柠檬酸型水果中含量高,导致此类水果酸感尖锐,加工产品的适口性、感官品质会受到不同程度的影响。柠檬酸可以被乳酸菌利用生成双乙酰、乙偶姻和丁二醇等香气化合物,也可以在酵母菌内转化为醇、乙醛酸、琥珀酸等多种代谢产物。不同的柠檬酸降解途径赋予柠檬酸型水果加工产品的品质和风味有显著差异。该研究详细地阐述了乳酸菌、酵母菌生物降解柠檬酸的途径及主要代谢产物,分析了pH、碳源两种因素对生物降解柠檬酸的影响及生物降解柠檬酸在果汁、果酒等加工中的应用,指出了限制乳酸菌和酵母菌用于生物降解柠檬酸的条件,旨在为柠檬酸降解的研究及应用提供理论依据和技术参考。