生物电化学脱氮系统构建和影响因素的最新研究进展

生物电化学脱氮技术是一种以电化学活性细菌作为催化剂的污水处理技术，因其绿色、环保、节能的特点而备受关注。本文介绍了不同脱氮技术的机理，从脱氮性能、成本、二次污染大小和污染物转化率等角度对现有脱氮技术进行评价，指出了生物电化学脱氮技术的优势和应用前景；重点综述反应器运行参数、溶液组分、脱氮生物膜的培养方式、生物电化学脱氮系统内菌种构成等因素对生物电化学脱氮系统的影响，并提出了优化脱氮系统的方法；同时总结了生物电化学脱氮技术在处理屠宰场废水、焦化废水和含高氯酸盐废水等方面的应用现状。研究表明：从脱氮系统内不同微生物的角度，尤其是电活性微生物角度探究生物电化学脱氮过程的机理，调控脱氮生物膜的形成和改变脱氮系统运行参数，是改进生物电化学脱氮技术的有效途径。     

于都黄麟-祁禄山地区土地质量地球化学评价

通过对于都县黄麟-祁禄山地区开展1:5万土地质量地球化学调查,在野外土壤样品采集和化验测试的基础上,系统地研究了影响土地质量的各项地球化学指标特征与控制因素,基本查明有益元素、重金属元素分布,划分出重点污染区和绿色土地发展区,并进行土地质量等级评价,为永久基本农田建设、土地资源开发与利用等方面提出建议。     

UV/TiO_2光催化氧化工艺脱汞的试验研究

UV/TiO_2光催化技术在TiO_2催化剂的作用下可将烟气中Hg~0氧化脱除。利用自制的UV/TiO_2氧化试验台研究了影响Hg~0去除率的相关因素,结果表明,在无催化剂和有紫外灯情况下可脱除少量Hg~0;Hg~0去除率随催化剂活性组分含量的增加而上升,但上升速率逐渐下降;在温度(50～200)℃范围内,Hg~0去除率无明显变化;Hg~0去除率随着Hg~0初始浓度的升高逐渐下降;Hg~0去除率随着烟气中氧含量先上升后趋于不变。UV/TiO_2氧化工艺脱汞可为燃煤电厂烟气脱汞提供理论指导。     

阴离子种类及浓度对RCT催化剂催化湿式氧化处理头孢废水的影响

采用催化湿式氧化法处理头孢类废水,以RCT为催化剂,考察了阴离子对污染物降解效果的影响。结果表明,不加阴离子时,RCT催化剂能有效催化污染物的降解,TOC和TN去除率分别为78.3%和85.9%;投加不同阴离子对反应的影响不同。RCT催化剂可将头孢氨苄废水中的有机N转化为$N_{2}$,少部分以$NO_{3}-N$形式存在;阴离子F^-、Cl^-、Br^-、I-及$S^{2-}_{4}$对TN的降解影响不大,而$N^{-}_{3}$、$P^{3-}_4$、$CO^{2-}_{3}$、$Si^{2-}_{3}$及$B_{4}O^{2-}_{7}$则明显抑制了对TN的去除。投加F^-、Cl^-、Br^-、I-及$NO^{-}_{3}$对TOC的降解有促进作用(I^-> F^-> Cl^-> Br^-> $NO^{-}_{3}$),TOC的降解率提高了3.1~18.6个百分点;而投加$S^{2-}_{4}$、P,$P^{3-}_4$、$CO^{2-}_{3}$、$SiO^{2-}_{3}$及$B_{4}O^{2-}_{7}$对TOC的降解有抑制作用($SiO^{2-}_{3}$> ,$P^{3-}_4$> $CO^{2-}_{3}$> $B_{4}O^{2-}_{7}$> $S^{2-}_{4}$),TOC的降解率降低了2.0~46.9个百分点。研究Cl-浓度对RCT催化剂降解效果的影响,当Cl-为0.1 mol·L-1时,对TOC的去除有抑制作用,而较高的Cl-浓度(≥0.3 mol·L-1)对TOC的去除却有促进作用,投加Cl-对TN的去除有促进作用,但随着Cl-浓度的增加[(0.1~0.8) mol·L-1],TN的去除率变化不明显(约为88%)。     

环保法规对船舶涂料企业的冲击及应对措施的探讨

随着我国环境保护法规《大气污染防治法》的修订和《涂料征收消费税通知》的公布,探讨了其对船舶涂料企业的冲击及其应对措施。     

Variation-aware approaches with power improvement in digital circuits

In submicron technology, during the fabrication process factors like lithography and lens defect can change some of the physical parameters of transistors and interconnects. This change can modify the transistor electrical characteristics such as current, threshold voltage and gate capacitance, and thus it causes variation in power, delay and performance of the circuit. Process variation has become one of designer׳s challenges to the point that in below 45 nm technology it is considered as the most important issue in reliability. Power consumption and transistors variation are limiting factors to physical scalability. In this paper, we propose two approaches to reduce D2D and WID variations effects on digital CMOS circuits, at design time. The first approach concerns a variation-aware algorithm capable of extracting optimal design parameters to decrease variation and power. The second approach, using transistor stacking will help further reduce variation and power. Applying the algorithm on a digital design and according to parameters behavior in the presence of variation, we extract for each parameter value that will lead to power and variation reduction. On the other hand, with the stacking approach only basic gates are considered and subsequently gate configurations that reduce power and variation are proposed. The proposed approaches could be used identically for synchronous and asynchronous circuits. To prove this claim, we apply our approaches to a network-on-chip asynchronous router and a circuit from the ISCAS85 benchmark. All simulations are done in 32 nm technology using the HSPICE tool. The proposed algorithm similar to Monte Carlo simulation achieves the same results; however with lower execution time. The application of stacking approach to both asynchronous router and ISCAS85 circuit reduces variation effects up to 40.9% and 13.35%, respectively.     

A methodological approach for manufacturers to enhance value-in-use of service-based offerings considering three dimensions of sustainability

To shift towards a sustainable society, lifecycle engineering methodologies addressing the social dimension need to be advanced. A new methodological approach is proposed for manufacturers to address the three dimensions of sustainability. This approach aims to enhance value-in-use of service-based offerings and supports designers with two social indicators and five generally applicable recommendations involving multiple product lives towards a circular economy. For validation, it was applied to the case of a manufacturer of washing machines for European consumer markets. Results show that the approach supports designers to incorporate the social dimension efficiently while improving resource efficiency.     

多中心治理视角下经济与生态共赢的路径与启示

改革开放40年来,我国经济飞速发展的同时也产生了一系列的生态环境问题,土壤重金属污染问题尤为严重。上世纪80年代,江西贵溪地区数家大中型冶炼、化工类企业在九牛岗区域逐渐集中,由于长期对资源的粗放型开发,高耗能、高污染、高排放加之低效率生产对贵溪J区域农田造成了严重污染,土壤重金属含量严重超标,生态环境遭到破坏。污染治理过程中,各相关主体从“各自为政”到“共同发力”,从长期得不到有效解决到多主体相互协作综合治理取得成效,走出了一条政府主导,企业主体,村民参与,社会支持的土壤重金属污染治理新路。本文着重就自然资源、环境保护与社会经济如何协调发展,探索运用多中心治理理论对土壤污染治理进行实践,推动经济发展与生态环境和谐共进。     

Biodegradability Study of the Biosurfactant Contained in a Crude Extract from Corn Steep Water

Over the last few years, the global biosurfactant market has raised due to the increasing awareness among consumers, for the use of biological or bio-based products. Because of their composition, it can be speculated that these are more biocompatible and more biodegradable than their chemical homologous. However, at the moment, no studies exist in the literature about the biodegradability of biosurfactants. In this work, a biosurfactant contained in a crude extract, obtained from a corn wet-milling industry stream that ferments spontaneously in the presence of lactic acid bacteria, was subjected to a biodegradation study, without addition of external microbial biomass, under different conditions of temperature (5–45 °C), biodegradation time (15–55 days), and pH (5–7). For that, a Box–Behnken factorial design was applied, which allowed to predict the percentage of biodegradation for the biosurfactant contained in the crude extract, between the range of the independent variables selected in the study, obtaining biodegradation values between 3 and 80%. The percentage of biodegradation for the biosurfactant was calculated based on the increase in the surface tension of samples of the crude extract. Furthermore, it was also possible to predict the variation in t_1/2 for the biosurfactant (time to achieve the 50% of biodegradation) under different conditions.