A user evaluation of biodegradable cutlery

This paper summarizes a study evaluating the acceptance and perceived performance of disposable cutlery made from starch-based biodegradable resins relative to nondegradable polystyrene cutlery. Two hundred forty-three sailors onboard three U.S. Navy vessels ate their lunch using either biodegradable cutlery made with resins manufactured by one of two commercial companies or polystyrene cutlery. The cutlery was rated on several sensory and performance dimensions as well as for overall acceptability. Results indicated that sailors rated both the biodegradable and the polystyrene utensils as easy to hold. There were also no differences in the perceived ease of using each of the spoons. However, compared to the polystyrene utensils, both types of biodegradable utensils were viewed as less sturdy, as having a less attractive color, and as being less acceptable overall. The biodegradable forks and knives were also rated as more difficult to use for piercing and cutting food than the polystyrene ones. In addition, several significant differences emerged between the two types of biodegradable cutlery. The results are discussed in terms of the need for continued consumer testing of products developed from biodegradable polymeric materials.     

Evaluation of Material Biodegradability in Real Conditions–Development of a Burial Test and an Analysis Methodology Based on Numerical Vision

This work validated a burial protocol for in situ testing and presents a robust, repeatable and time-saving technique to measure degraded areas in the sample, i.e. an image analysis method. 1440 specimens of degraded samples have been compiled in a data base. To this end, twenty samples presenting different levels of biodegradability (i.e. PHBV/HV, PLA, PCL, PCL-Starch, paper, PE, PE-Starch) were buried at 4 different locations and then disinterred at 4, 6, 9, 12, 18, and 24-month intervals. The biodegradation levels of these samples were determined by computing weight and area loss. Weight loss was measured after careful cleaning, whereas area loss was quantified using image analysis. Image analysis gives reliable information on visual pollution while only requiring a rudimentary and thus quicker cleaning of the samples.     

Isolation and Identification of Microorganisms Able to Grow on the Polyester Amide BAK 1095

The polyester amide BAK 1095 is fully degraded by microorganisms. Bacteria that can grow on this polymer were isolated from various environments, such as freshwater, saltwater, arable land, woodland and compost. The mechanism of polymer degradation was examined using selected isolates. It was discovered that the bacteria selectively cleave the polymer at its ester bonds, releasing low-molecular water-soluble oligoamides. These can then be metabolised by other microorganisms [1, 2, 3]. The isolates were also tested for their ability to break down other ester-containing polymers such as Degranil W 50, a linear polyester urethane urea. Eight of the 12 strains examined were also able to break down this polymer.The isolated microorganisms predominantly belong to the genus Bacillus. Mesophilic, halophilic and thermophilic species were isolated. The studies show that polyester amide-degrading bacteria occur in numerous ecosystems and provide data on the microbial breakdown of random copolymers. Information was also obtained on the mechanism involved in the microbial breakdown of polyester amides.     

Characterization and recycling of polymeric components present in cell phones

The cell phone market is developing at a rapid speed. Today there are more than 1.6 billion consumers in the world, and the lifetime of a cell phone is less than 2 years. As a consequence, there is an increase in the waste associated to this product, and many alternatives to the disposal of the cell phones are being studied, such as recycling which shows to be the most important. It is crucial to know what materials constitute the cell phone in order to carry out recycling and determine environmental and economical issues. This work presents an evaluation of the cell phone components, characterizing the raw materials and some properties of the recycled materials.     

丁苯橡胶生产过程中不稳定因素分析及对策

针对丁二烯自聚物闪燃爆炸和后处理胶粒塑化着火的形成机理、形成条件、影响因素进行了分析,并提出了防范措施和应急处理办法。     

Molecularly imprinted polymer for analysis of trace atrazine herbicide in water

A molecularly imprinted polymer (MIP) for atrazine was synthesized by non-covalent method. The binding capacity of MIP was 1.00 mg g^{? 1} polymer. The selectivity and recovery were investigated with various pesticides which are mostly, found in the environment, for both similar and different chemical structure of atrazine. The competitive recognition between atrazine and structurally similar compounds was evaluated and it was found that the system provided highest recovery and selectivity for atrazine while low recovery and selectivity were obtained for the other compounds. The highest recovery was obtained from MIP compared with non-imprinted polymer (NIP), a commercial C₁₈ and a granular activated carbon (GAC) sorbent. The method provided high recoveries ranged from 94 to 99% at two spiked levels with relative standard deviations less than 2%. The lower detection limit of the method was 80 ng L^{? 1}. This method was successfully applied for analysis of environmental water samples.     

天然胶/公共网络/废胶粉互穿聚合物网络

通过互穿聚合物网络技术成功制备了天然橡胶/公共网络/废胶粉共轭三组分,并测定了力学性能和微观形态。结果表明:当A/B摩尔比为2/1、AB含量为4.5%、废胶粉粒径为60目、废胶粉含量为15%时,体系的力学性能最好,共轭三组分天然橡胶/公共网络/废胶粉体系的磨耗体积明显低于两组分天然橡胶/废胶粉体系的磨耗体积。界面共轭互穿改善了界面结合,可减少反复压缩过程中的相间摩擦生热和变形。     

聚合物/表面活性剂二元体系对油水界面性质的影响

文章应用界面张力仪、Zeta电位仪和表面黏弹性仪测定了聚合物、表面活性剂及其二元复合体系的质量浓度对油水界面性质的影响,并应用透射电镜观察了采出液的液膜结构。结果表明,随着聚合物质量浓度的增加,油水界面的界面剪切黏度值和界面张力值增大,颗粒表面Zeta电位的绝对值增大;随着表面活性剂质量浓度的增加,油水界面的界面剪切黏度变化幅度很小,但界面张力显著减小,颗粒表面Zeta电位绝对值增大;聚合物与表面活性剂复合能够形成稳定的聚合体,具有较大的界面剪切黏度值,较小的界面张力和较高的Zeta电位值;体系中聚合物、表面活性剂及水中悬浮物形成了类似"晶体"结构。     

磁性纳米铁对厌氧颗粒污泥特性及其微生物群落的影响

考察了磁性纳米铁(Fe3O4NPs)对厌氧颗粒污泥溶解性微生物产物(SMP)、疏松胞外聚合物(LB-EPS)、紧密胞外聚合物(TB-EPS)的影响,同时利用高通量测序技术对厌氧颗粒污泥内微生物群落结构的变化进行了分析.结果表明,在长期接触实验过程中,投加Fe3O4NPs的反应器对COD去除率为83.6%,与对照组相比降低了5.7%.对照组与实验组中厌氧颗粒污泥TB-EPS含量(以VSS计)分别为178.20 mg·g-1和138.24 mg·g-1,而SMP含量分别为34.88 mg·L-1和27.44 mg·L-1;同时投加Fe3O4NPs后,在LB-EPS三维荧光(EEM)光谱中,紫外光区类腐殖酸荧光峰消失,辅酶F420荧光峰强度有所降低.在长期接触实验后,甲烷杆菌属(Methanobacterium)所占比例从76.15%增至86.76%,而甲烷丝菌属(Methanothrix)所占比例从17.1%降至7.51%,Methanothrix对于Fe3O4NPs更为敏感;总细菌群落变化明显,其中变形菌门(Proteobacteria)所占比例从66.44%降至47.16%,放线菌门(Actinobacteria)所占比例从8.97%增至17.33%,拟杆菌门(Bacteroidetes)所占比例从8.07%增至17.74%,厚壁菌门和拟杆菌门比例的增加对有机物的厌氧水解过程发挥积极的作用.     

聚糖菌颗粒污泥基于胞内储存物质的同步硝化反硝化

采用特殊运行方式的厌氧-好氧SBR系统(厌氧后排水),以乙酸钠为有机基质成功富集了聚糖菌颗粒污泥.聚糖菌颗粒污泥厌氧-好氧批式实验表明,聚糖菌颗粒污泥具有较强的SND能力,TOC/N分别为5.0,4.0,2.8时,SND效率分别96.4%、95.3%及96.2%,而周期总氮去除效率随着碳氮比降低而降低,分别为66.0%、61.2%及56.3%.通过对周期氨氮、亚硝酸盐氮、硝酸盐氮、TOC以及胞内糖原、PHB变化的测定分析,证明聚糖菌颗粒污泥SND过程中,污泥以厌氧阶段储存于胞内的多聚物PHB作为反硝化碳源,并且反硝化聚糖菌是系统中反硝化能力的来源.与溶解性基质相比,PHB的降解速率相对较低,因此在SND过程中,反硝化可以与硝化保持相近的速率,从而有助于获得良好的SND效果.