生物基聚合物PHBV和PLA复合材料在不同介质中的生物降解及其影响因素

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.     

金属-有机骨架MIL-88A(Fe)及其复合物的合成与高级氧化降解水体有机污染物的研究进展

本文综述了MIL-88A(Fe)及其复合物的合成方法、形貌调控及其作为异相催化剂实现光芬顿、活化PS(persulfate, 过硫酸盐)和催化臭氧氧化等高级氧化过程去除水体有机污染物的研究进展. 系统介绍了利用水/溶剂热法、超声法、微波法、室温搅拌法、机械化学法、重结晶法和光化学还原法制备MIL-88A(Fe)及其复合物的反应条件和产物形貌特征. MIL-88A(Fe)具有环境友好、能被可见光激发及稳定性好等特点,其表面Fe(Ⅲ)不饱和位点丰富且均匀,利于作为催化剂用于高级氧化. MIL-88A(Fe)受光激发产生的光生电子-空穴容易复合,导致其光催化性能较差. 但在类芬顿、激发PS和催化臭氧氧化等体系中,添加的氧化剂作为电子受体快速消耗电子,有效克服了光生电子-空穴复合问题. 此外,将MIL-88A(Fe)与其他功能材料复合可进一步改善其光生电子-空穴分离效率、提高光吸收能力及水稳定性. 总之,MIL-88A(Fe)及其复合物在光芬顿、活化PS和催化臭氧氧化降解有机污染物方面具有较大的实际应用潜力.      

土壤氮素的转化过程中温室效应气体的释放和吸收

一氧化二氮(NO₂)是一个重要的温室效应气体,一氧化氮(NO)对温室效应的产生也有间接的作用。土壤作为这两种气体的主要来源的重要性引起了人们的广泛重视。本文主要讨论了土壤中的氮素生物转化过程与NO₂和NO的产生和再利用。以及影响土壤中温室效应气体的释放和吸收的环境条件。      

高级氧化技术在垃圾渗滤液处理中的应用

垃圾渗滤液是一种成分非常复杂的高浓度有机废水,生物法处理难以适应其水质的变化,文章介绍了光催化氧化、催化湿式氧化、Fenton氧化、电化学氧化及相应的催化氧化、化学氧化、等离子体技术、超声波技术等高级氧化技术的机理,总结了它们应用于垃圾渗滤液处理的影响因素和效果,高级氧化具有反应速度快、无二次污染、水质适用范围广、对垃圾渗滤液中有机污染物降解彻底等特点,但同时也受到水量和成本的限制,最后指出高级氧化技术之间的优化组合以及将其作为预处理单元与生化联合处理垃圾渗滤液应是今后的主要研究方向.     

Assessment of the environmental profile of PLA,PET and PS clamshell containers using LCA methodology

Life cycle assessments of bio-based polymer resin and products historically have shown favorable results in terms of environmental impacts and energy use compared to petroleum-based products. However, calculation of these impacts always depends on the system and boundary conditions considered during the study. This paper reports a cradle-to-cradle Life Cycle Assessment (LCA) of poly(lactic acid) (PLA) in comparison with poly(ethylene terephthalate) (PET) and poly(styrene) (PS) thermoformed clamshell containers, used for packaging of strawberries with emphasis on different end-of-life scenarios. It considers all the inputs such as fertilizers, pesticides, herbicides and seed corn required for the growing and harvesting of corn used for manufacturing PLA. For PET and PS, the extraction of crude oil and the entire cracking processes from crude oil through styrene and ethylene glycol and terephathalic acid are considered. Global warming, aquatic acidification, aquatic eutrophication, aquatic ecotoxicity, ozone depletion, non-renewable energy and respiratory organics, land occupation and respiratory inorganics were the selected midpoint impact categories. The geographical scope of the study reflects data from Europe, North America and the Middle East. PET showed the highest overall values for all the impact categories, mainly due to the higher weight of the containers. The main impacts to the environment were the resin production and the transportation stage of the resins and containers. This implies that the transportation stage of the package is an important contributor to the environmental impact of the packaging systems, and that it cannot be diminished.     

实时荧光定量PCR技术对氨氧化细菌的研究

传统的PCR技术只能实现对核酸的定性检测而无法对其进行定量研究。随着分子生物学技术的发展,在传统PCR技术的基础上发展起来的实时荧光定量PCR技术实现了对核酸的定量研究。该技术是向常规PCR反应体系中加入荧光染料或荧光探针,通过监测PCR反应过程中荧光信号的变化来实现对核酸的定量。实时荧光定量PCR技术具有应用范围广、灵敏度高、操作简单、工作量低等特点,在医学和微生物学领域已广泛地应用于疾病诊断、病毒定量检测、微生物群落结构分析及演替规律的研究。文章综述了该项技术的原理、特点及其在环境氨氧化细菌研究中的应用,同时也指出了该技术存在的问题及其发展应用前景。     

Constructed wetlands for wastewater treatment in cold climate — A review

Constructed wetlands (CWs) have been successfully used for treating various wastewaters for decades and have been identified as a sustainable wastewater management option worldwide. However, the application of CW for wastewater treatment in frigid climate presents special challenges. Wetland treatment of wastewater relies largely on biological processes, and reliable treatment is often a function of climate conditions. To date, the rate of adoption of wetland technology for wastewater treatment in cold regions has been slow and there are relatively few published reports on CW applications in cold climate. This paper therefore highlights the practice and applications of treatment wetlands in cold climate. A comprehensive review of the effectiveness of contaminant removal in different wetland systems including: (1) free water surface (FWS) CWs; (2) subsurface flow (SSF) CWs;and (3) hybrid wetland systems, is presented. The emphasis of this review is also placed on the influence of cold weather conditions on the removal efficacies of different contami-nants. The strategies of wetland design and operation for performance intensification, such as the presence of plant, operational mode, effluent recirculation, artificial aeration and in-series design, which are crucial to achieve the sustainable treatment performance in cold climate, are also discussed. This study is conducive to further research for the understanding of CW design and treatment performance in cold climate.     

Use of LCA to evaluate the environmental benefits of substituting chromic acid anodizing (CAA)

Chromic acid anodizing processes are currently being replaced in many industrial sectors because of the recognized adverse effect on the environment and health of used hexavalent chromium compounds. The environmental impacts of the existing processes must, however, be quantified in order to constitute a baseline against which the environmental performance of potential alternative options could be compared. The whole life cycle of the process should also be taken into account to ensure that the possible chosen solution for eliminating or lowering chromium (VI) emissions would not drastically damage the overall process performance in other environmental areas. In our study, we used a simplified life cycle assessment methodology that only took into account the key environmental issues of the considered industrial sector. Both the scope and the data needs were reduced by focusing only on significant flows and by using a generic database for steps other than the anodizing one. A precise literature review was carried out to evaluate bath atmospheric emissions. The results of the performed assessment confirmed that the only way to efficiently deal with hexavalent chromium compounds is to substitute the electrolyte used in the bath as the most Cr(VI) emissions are caused by other stages than the main one. Other specific issues, such as water and energy consumptions have, nevertheless, to be studied throughout the whole life cycle of the chemical substitute to monitor performance against CAA.     

A design for the additive manufacture of functionally graded porous structures with tailored mechanical properties for biomedical applications

CAD/CAM-based layered manufacturing and additive manufacturing techniques of metals have found applications in near-net-shape fabrication of complex shaped parts with tailored mechanical properties for several applications. Especially with the onset of newer processes such as electron beam melting (EBM) and direct metal laser sintering (DMLS), revolutionary advances may be achieved in material substitution in the medical implant industry. These processes must be suitably developed and tested for the production of medical grade substitutions. In this article, we discuss a design process for creating periodic cellular structures specifically targeted for biomedical applications. Electron beam melting is used to fabricate the parts. Evaluation of the mechanical properties is performed and compared with design parameters. Compression tests of the samples show effective stiffness values ranging from 0.57 (±0.05) to 2.92 (±0.17) GPa and compressive strength values of 7.28 (±0.93) to 163.02 (±11.98) MPa. Substituting these values for simulation of biomechanical performance of patient-specific implants illustrates the compatibility and matched functional performance characteristics of highly porous parts at a safety factor of 5 and an effective reduction in weight. These developments are unique for the construction of maxillofacial and craniofacial implants. The novel design strategy also lends itself very well to metal additive manufacturing technologies. Implants designed and fabricated with this design strategy and manufacturing process would have mechanical properties equivalent to the part they replace and restore better function and esthetics as against the currently used methods of reconstruction. Suitable examples of a titanium porous cranioplasty plate and a sandwich structure are illustrated.     

全氟类化合物的检测与治理研究进展

全氟类化合物的生产和使用已超过50年。近几年来,研究人员逐渐开始关注全氟类化合物对环境、生物和人类健康的影响,并发展成为全球性的热点问题,已开展了较为广泛而深入的研究。在概述了全氟类化合物的特性与污染现状的基础上,从检测技术研究与治理手段研究等两个方面较为系统地综述了近年来国内外学者对以全氟辛烷磺酸和全氟辛烷羧酸为代表的全氟类化合物的研究进展,着重介绍了液相色谱-质谱联用技术与吸附分离技术分别在全氟类化合物检测与治理中的应用,并对未来该领域的研究方向与趋势进行了一定的展望。     

赤潮甲藻毒素麻痹性贝毒的生物合成研究进展

简要介绍了赤潮甲藻毒素麻痹性贝毒的生物合成过程及毒素结构的化学转换和生物转换方面的研究进展。包括利用放射性标记物质喂养产毒甲藻Gonyaulax tamarensis的研究实验,提出了该甲藻是通过一个乙酸单元或者它的衍生物与精氨酸或其等价物在α碳上的胺基的克莱森聚合(CLAISEN),随后失去羰基碳,并在相邻的羰基碳上形成咪唑环而合成麻痹性贝毒的理论过程。还介绍了N-磺酰基耦联的麻痹性毒素被弱酸和生物系统中的N-磺酰酶水解时结构转换方面的研究进展。也介绍了我国的研究进展和该领域今后的研究方向。     

The role and implementation of LCA within life cycle management at Alcan

Life cycle management (LCM) aims at expanding the scope of the environmental management system of a company to address the up- and downstream impacts associated with the activities of its suppliers and customers. It is based on a perspective that focuses on products and the corresponding processes in addition to facilities and production sites. Therefore, the life cycle assessment (LCA) methodology plays a central role in implementing LCM. At Alcan, one of the world's leading producers of aluminum materials and products, as well as composite components and packaging solutions, LCA as a core element of LCM is being used for a variety of applications. In order to achieve the objectives of LCM and to ensure efficient decision support, the LCAs are performed in a simplified mode. Simplifications predominantly concern up- and downstream processes outside of Alcan's direct control as well as impact assessment procedures, the reuse of internal life cycle inventory analysis modules, and the aggregation and presentation of the results for top-management and other internal decision-makers. A recently completed LCA from the automotive sector demonstrates the ongoing implementation of LCA at Alcan.     

固定化聚铝的制备及在纸品加工废水处理中的应用

经水解尿素均匀沉淀 灼烧 ,在素瓷表面制备可能有共价结合的铝胶膜 ;铝胶薄膜载体与经复分解反应制得的氯化铝悬浊液共熟化 ,在其表面生成聚铝 ,经烧结进一步固化而制得固定化聚铝絮凝剂。经三级固定化絮凝剂床处理 ,纸品加工废水的COD、BOD、悬浮物、硫化物、色度等指标可分别降低 93 %、77%、97%、94%、80 %。     

How to be a more effective environmental scientist in management and policy contexts

This paper is intended for young researchers with an environmental conscience, alerting them that a self-centred ecology can work against conservation and other desirable goals. I propose that there is confusion in the biophysical ecologists’ community about the role of knowledge, stemming from several already surpassed beliefs that have been strongly criticized by scholars in the field of science and technology studies. In particular, environmental scientists still often seem trapped in the information deficit model, assuming a linear and unidirectional flow of knowledge from experts to users. This leads to an incomplete understanding and unrealistic expectations of ongoing processes of citizen participation (co-production of knowledge), impatience regarding the speed at which issues can be dealt with by politics, and a fuzzy notion of the role of our convictions regarding the value of nature conservation when we are consulted as experts. I analyse the consequences of disregarding tacit knowledge, i.e. the one knowledge beyond that codified in academic papers and books. I emphasize that preferences and values have a large influence on how we perceive, process, and act (or postpone to act) on information on our non-exclusive roles as scientists, decision makers or citizens. I argue that this is why political and ideological preferences have a large influence not only on which teams are appointed to solve problems, but also on which situations are perceived as problematic and given higher priorities. I include a cheat-sheet to enhance communication with decision-makers and other non-scientists that could prevent environmental zeal to be transformed into society’s annoyance and our eventual irrelevance. I plea for a more realistic attitude towards ecological research, highlighting that in environmental debates we are also long-term stakeholders, and not only casual, external and aseptic observers.     

络合剂和酸度控制对土壤铬电动过程的影响

研究了添加络合剂和控制阴极池溶液酸度对铬在黄棕壤中电动过程的影响.结果表明,EDTA 柠檬酸和乳酸的加入明显改变了电动过程中电渗流的大小和铬在土柱中的分配,其中柠檬酸因可与土壤中的 Cr(III)发生较强的络合作用而显著增加了土壤总铬的去除率(29.8%);改变阴极池溶液酸度不仅影响了电动过程中电流、电渗流的大小和铬在土柱中的分配,同时也显著改变了总铬的去除率.其中在 pH 6.0 和pH 10.0 时,总铬的去除率分别达 25.3%和 24.0%,较 pH 4.0 和 pH 8.0 时增高近 1 倍.所有电动处理以后土壤中剩余的六价铬浓度均显著减少,约降低 80%,表明电动处理对土壤中六价铬(铬的主要有毒形态)的去除是非常有效的.     

Biologie und Biochemie des Elements Selen

The importance of selenium as an essential trace element has progressively emerged during the last years due to the analysis of selenium deficiency diseases and to the identification and characterization of a number of selenoenzymes. Selenium is incorporated in the catalytic site of the enzymes as an integral selenocysteine residue. The pathway of selenocysteine biosynthesis and incorporation has been elucidated recently for Escherichia coli. This article presents an overview on these subjects and describes the mechanisms which confer selenocysteine specificity in the framework of protein biosynthesis. In addition, some considerations concerning the phylogeny of selenocysteine incorporation are presented and a model for the evolution of the selenocysteine pathway is proposed.     

Origin of Metazoa: Sponges as Living Fossils

Geodia cydonium  , which code for proteins. The analyses of their deduced amino acid sequences allowed a molecular biological approach to solve the problem of monophyly of Metazoa. Molecules of the extracellular matrix/basal lamina, with the integrin receptor, fibronectin, and galectin as prominent examples, cell-surface receptors (tyrosine kinase receptor), elements of sensory systems (crystallin, metabotropic glutamate receptor), and homologs/modules of an immune system (immunoglobulin like molecules, scavenger receptor cysteine-rich, and short consensus repeats, rhesus system) classify the Porifera as true Metazoa. As living fossils, provided with simple, primordial molecules allowing cell-cell and cell-matrix adhesion as well as processes of signal transduction as known in a more complex manner from higher Metazoa, they also show peculiarities not known in other metazoan phyla. Tissues of sponges are rich in telomerase activity, suggesting a high plasticity in the determination of cell lineages. It is concluded that molecular biological studies with sponges as model will not only help to understand the evolution of Protoctista to Metazoa but also the complex, hierarchial regulatory network of cells in higher Metazoa.     

厌氧污泥胞外多聚物的提取、测定法选择

选用６种方法,对４种不同性状的厌氧污泥的胞外多聚物（ＥＣＰ）进行提取试验。此外,采用２种方法测定提取液中多糖浓度,还测定核酸浓度以检查细胞的破坏程度。通过对比,认为硫酸法提取的ＥＣＰ较完全,对细胞的破坏作用小,而苯酚－硫酸法较适于测定提取液中的多糖含量。文中还对厌氧污泥ＥＣＰ的含量、成分作了分析和探讨。     

原子力显微镜在环境样品研究与表征中的应用与展望

简要阐述了原子力显微镜仪器操作原理及最新成像技术发展情况;结合作者近期的研究工作,从环境微生物界面观察与表征、腐殖酸在微界面上的聚集行为观测、无机高分子絮凝剂的界面形貌及行为观察以及膜材料表面结构观测与表征等4个方面对原子力显微镜在环境领域内的应用情况作了概括介绍．最后,对原子力显微镜在环境微界面研究与表征中的应用前景进行了展望。     

Response mechanism of Chlamydomonas reinhardtii to nanoscale bismuth oxyiodide (nano-BiOI): Integrating analysis of mineral nutrient metabolism and metabolomics

Nanoscale bismuth oxyiodide (nano-BiOI) is widely studied and applied in environmental applications and biomedical fields, with the consequence that it may be deposited into aquatic environments. However, the impact of nano-BiOI on aquatic ecosystems, especially freshwater microalga, remains limited. Herein, the nano-BiOI was synthesized and its response mechanism towards microalga Chlamydomonas reinhardtii was evaluated. Results showed that a low concentration of nano-BiOI (5 mg/L) could stimulate algal growth at the early stage of stress. With the increase in concentration, the growth rate of algal cells was inhibited and showed a dose effect. Intracellular reactive oxygen species (ROS) were significantly induced and accompanied by enhanced lipid peroxidation, decreased nonspecific esterase activity, and significantly upregulated glutathione S-transferase activity (GST) activity. Mineral nutrient metabolism analysis showed that nano-BiOI significantly interfered with the mineral nutrients of the algae. Non-targeted metabolomics identified 35 different metabolites (DEMs, 22 upregulated, and 13 downregulated) under 100 mg/L BiOI stress. Metabolic pathway analysis demonstrated that a high concentration of nano-BiOI significantly induced metabolic pathways related to amino acid biosynthesis, lipid biosynthesis, and glutathione biosynthesis, and significantly inhibited the sterol biosynthesis pathway. This finding will contribute to understanding the toxicological mechanisms of nano-BiOI on C. reinhardtii.