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11.
传统工艺的塑料生产不仅依赖石油资源的持续开发利用,同时给环境造成了前所未有的压力,近年来生物基聚合物(聚(3-羟基-3-戊酸酯)-PHBV,聚乳酸-PLA)日渐成为传统石油基塑料的替代产品.本文采用呼吸测试手段,旨在揭示均质复合材料在不同环境介质(土壤、熟化堆肥、水体)条件下及有机添加剂(木质素),无机添加剂(蒙脱石)和天然有机物链增长剂(Joncryl)作用下的生物降解特征.结果表明:当链增长剂Joncryl添加量为5%时,对所有介质PHBV和PLA复合材料产生显著抑制作用.Joncryl添加量为0.2%时,未对所测样品的生物降解行为产生干扰作用.在熟化堆肥介质中,PLA复合材料比PHBV基质混合物的生物降解速率明显降低.有机木质纤维添加剂(榛子壳粉末)单独在聚合物中添加或者和链增长剂Joncryl以及非有机添加剂(Dellite72T)共同作用下都可促进PLA聚合物中各组分的相容连接性.实验结果表明,新型添加剂在不同介质中以二元或三元添加的方式对生物降解过程产生重要影响,该研究将为新型材料使用后的生物降解效应提供理论依据. 相似文献
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Xiuzheng Zhuang Yanqin Huang Huacai Liu Hongyou Yuan Xiuli Yin Chuangzhi Wu 《环境科学学报(英文版)》2018,30(7):261-270
Sewage sludge (SS) and deinking sludge (DS) were used to comparatively study the hydrothermal dewatering of sludge with different components. For a better overview, an insight into the relationship between physicochemical properties and dewaterability of hydrothermal sludge was provided. Results found that not all kinds of sludge were suitably conditioned by hydrothermal treatment (HT) in term of the elevation of dewaterability. Higher hydrothermal temperature tended to enhance the dewaterability of SS rather than DS, which was supported by the variation of their physicochemical properties (including water distribution, bonding energy, extracellular polymeric substance (EPS), particles size, acid functional groups and zeta potential in this study). In addition, the changes in surface morphology suggested that the reverse effect of HT on sludge dewaterability was mainly due to their dewatering behavior. For SS, the destruction of EPS structure leaded to the release of bound water, thereby strengthening sludge dewatering. Conversely, “Bridging effect” generated by lignocellulose in DS was beneficial for sludge dewatering; however, the increasing hydrothermal temperature degraded part of lignocellulose and weakened “bridging effect”, finally resulting in worse dewaterability of DS. 相似文献
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目的研究碳纤维增强复合材料贮存条件下的性能变化趋势和寿命评估。方法对碳纤维增强复合材料开展四个不同温度条件下的热氧老化试验,按试验周期定期取样开展冲击性能测试,对试验数据采用寿命预估方法进行处理,对材料性能进行预估。结果通过数据计算分别得到我国热带海洋、干热沙漠等典型气候条件下的碳纤维增强复合材料贮存寿命分别为17.21~35.89年。结论碳纤维增强复合材料具有较好的贮存性能,在较为严酷的热带海洋气候和给定的失效判据条件下,寿命预计为17.21年。试验和数据处理方法可以较好地预计材料的性能变化趋势和开展寿命评估。 相似文献
14.
A novel analytical method has been established for on-line simultaneous determination of fluorene and acenaphthene,chrysene and benzo[a]anthracene (B[a]A) by polarization synchronous fluoromet.y (PSF) coupled to high performance liquid chromatography (HPLC). The detection limits were: 0.039, 0.046, 0.016 and 0.042 mgL-1 for fluorene, acenaphthene, chrysene and B[a]A, respectively. The proposed method has been successfisily applied to simultaneous determination of these PAHs in environmental air and marine sediment samples. 相似文献
15.
A membrane extraction-gas chromatography method was developed fordetermination of organophosphorus pesticides and related compounds including methamidophos, DDVP, dimethoate, methyl parathion, parathion, thiophosphoric acid trimethyl ester, and thiophosphoramidic acid dimethyl ester in water samples. In thismethod, surface-modified acetic cellulose membranes were used to extract the target analytes in water samples, the extracted analytes were back-extracted into a small amount of methanol, andgas chromatography with pulsed flame photometric detector (GC-PFPD) was used to determine the concentrations of targetanalytes in the extracts. The recoveries obtained for thetarget analytes spiked into the water samples ranged from 66to 94%. The method detection limit for each target analyte was 0.05 g L-1. The method developed in this study had shown the advantages of being cheap, simple, fast, and reliable. It had been used successfully to determine the concentrations of target analytes in river water samples. 相似文献
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ZHANG Jian-ying QIU Li-min HE Jia LIAO Yuan LUO Yong-ming College of Environmental Resource Sciences Zhejiang University Hangzhou China. Soil Environment Bioremediation Research Center Institute of Soil Science Chinese Academy of Sciences Nanjing China 《环境科学学报(英文版)》2007,(3)
A total of 198 agricultural soil samples were collected from Zhangjiagang and Changshu in Southern Jiangsu for analysis of 13 polychlorinated biphenyls (PCBs) in order to assess the levels of pollution, sources, area distribution, and potential risk for the environment. All methods were rigorously tested and an adequate quality control was ensured. Only one site had no PCBs residues, and the highest total PCBs concentration in the surface soils was 32.83 ng/g. The average concentration in all the soil samples was 4.13 ng/g, signaling low-level pollution. Tetra-, penta-, and hexa-chlorinated biphenyls were dominant species in soil samples, accounting for more than 75% ofΣPCBs in the soil samples. PCB118 was the most abundant congener in all the samples. The PCB118 was about 20% ofΣPCBs. The soil organic matter content showed only a weak correlation with the levels of all PCB congeners, in which a better correlation was noted for the more volatile lighter PCB congeners than for the heavier homologues. To a certain extent, the sources and land use seemed to influence the levels of PCBs. 相似文献
19.
可持续发展战略对环境保护参与国民经济决策提出新的要求.市场经济体制产生“市场失灵”,应加强宏观调控机制,保证经济与环境协调发展.探讨了社会主义市场经济条件下环境与发展宏观调控机制的思路与设想. 相似文献
20.
铜陵石炭纪威宁期沉积相及与黄铁矿矿床的关系 总被引:1,自引:0,他引:1
铜陵地区石炭纪威宁期存在潮坪相,泻湖相和浅海陆棚相。白云岩有两种,准同生白云岩分布于潮坪,成岩白云岩分布于泻湖内,本区以成岩白云岩为主。白云岩中赋存了层位稳定的黄铁矿矿床,黄铁矿在泻湖相最易富集,成岩作用是黄铁矿矿床形成的一个重要因素。 相似文献