汞胁迫对小麦幼苗抗氧化酶活性的影响

通过营养液培养实验,研究了小麦幼苗在遭受汞胁迫后,地上部及根系抗氧化酶活性的变化．试验表明:小麦幼苗受到汞胁迫后,地上部及根系的超氧化物歧化酶(ＳＯＤ)的活性均显著增加,过氧化氢酶(ＣＡＴ) 的活性也比对照有所增强,但不如ＳＯＤ酶变化迅速,表明ＳＯＤ酶活性是小麦幼苗遭受汞胁迫时比较敏感的生物标记物．但是,小麦幼苗地上部及根系的丙二醛(ＭＤＡ) 含量仍均比对照显著升高,表明小麦幼苗的膜系统受到了一定程度的破坏．试验同时还反映出,汞胁迫对小麦幼苗根系的影响强于对地上部的影响．     

Estimation of septic tank setback distances based on transport of E. coli and F-RNA phages

Setback distances between septic tank systems and the shorelines of Lake Okareka, New Zealand were determined from model simulations for a worst-case scenario, using the highest hydraulic conductivity and gradient measured in the field, removal rates of the microbial indicators (Escherichia coli and F-RNA phages) determined from a column experiment, and maximum values of the design criteria for the disposal system, and assuming an absence of an unsaturated zone, a continuous discharge of the raw effluent from a failed or non-complying treatment system (both indicators at concentrations of 1x10(7) counts/100 ml) into the groundwater and no sorption of pathogens in the aquifer. Modelling results suggest that the minimal setback distances were 16 m to satisfy the New Zealand Recreational Water Quality Guidelines for E. coli <126 per 100 ml (Ministry for the Environment, 1999) and 48 m to meet the Drinking-Water Standards for New Zealand 2000 for enteric virus <1 per 100 l (Ministry of Health, 2000). These distances may be applicable for other lakeshores in pumice sand aquifers with groundwater velocities <7 m/day. Findings of laboratory column and batch experiments provided an insight into the microbial attenuation and transport processes in pumice sand aquifers. Bacterial removal was predominately through filtration (87-88%) and partially by die-off (12-13%), while viral removal was by both die-off (45%) and filtration (55%). In addition, microbial die-off in groundwater without aquifer material (i.e., free microbes) was much lower than die-off in groundwater with aquifer material (i.e., sorbed microbes) and contributed only 2-6% to the total removal. This implies that the setback distances estimated from die-off rates for the free microbes, determined in the laboratory without considering aquifer media and other removal processes, which are often reported in the literature, could be larger than necessary.     

中国降水量高度效应及全球升温对它的影响

利用中国气象中心160站点的实际观察资料,对中国半个世纪的降水变化进行了系统分析,发现中国的夏季降水量与海拔高度存在着很好的反相关关系;同时,全球升温使得降水量的高度效应增强,主要表现为高海拔降水量海拔效应明显增强,这主要是由全球升温引起环流系统增强所引起的.     

二级UASB厌氧工艺在制药废水中的应用

抗菌素制药污水复杂,其CODCr高达39000mgL,硫酸盐的浓度在6500mgL左右,常规工艺很难处理,山东某制药厂采用了二级厌氧工艺处理此类废水,取得了良好的处理效果和经济效益。     

基于Kaya方法的四个直辖市碳效率评价与比较

应用Kaya恒等式的计算方法对我国4个直辖市2005-2009年的碳效率进行了评价和比较分析,结果显示:4个直辖市碳效率的排序在2005-2009年间没有发生变化,4个城市的碳效率都处于上升态势。     

Linking China’s emissions trading pilot schemes

All seven emissions trading pilots in China operate independently. One challenge facing most of them is the low inclusion thresholds for enterprises and the few total covered emissions, which negatively influences the effects of the emissions trading systems (ETSs). Some pilot sites, such as Guangdong, Hubei, Tianjin and Beijing, have indicated their willingness to link their schemes with others. ETS linking could expand scheme coverages and therefore help to reduce the overall costs of achieving the linked schemes’ emissions control targets. Linking could also help to address the issues of carbon leakage and reduce price fluctuations. The potential benefits and feasibility of linking different pilot systems are analyzed in this article. The seven pilot regions are at different stages of social and economic development, with significant differences in total emissions and emissions structures as well as carbon abatement potentials and costs. Through linking, more-developed regions such as Beijing, Shanghai and Shenzhen, which are typically considered to face higher mitigation costs, will have the opportunity to achieve their emissions control targets by purchasing carbon units from less-developed regions, which will earn financial revenues from selling the units. To realize this win-win result, a series of policy and technical barriers at both the central government and pilot government levels needs to be overcome. Establishing a unified national emissions trading market would appear to be the ideal solution to these challenges, but it will take considerable time and will not be the short-term solution. In the absence of a unified national scheme, it is recommended that the central government encourage pilot schemes to link, that it develops corresponding national policies to support the linking efforts and that the pilot schemes that are intended to be linked coordinate on certain design elements. Based on the coordinating need, the major elements of an ETS can be divided into four categories: elements that need mutual recognition (cap setting and allowance allocation methods); elements that should be completely identical (compliance mechanisms, price containment measures, banking and borrowing rules, and offset mechanisms); technical elements that are preferably identical and easy to coordinate (MRV standards, technical registry standards); and elements that require no coordination (coverages and scopes).     

Application of hinokitiol potassium salt for wood preservative

The decay of wood and other cellulosic materials by fungi cause significant economic loss. The widely used chromated copper arsenate was prohibited for the environmental impact and safety of arsenic and chromium. It was found that natural product hinokitiol (HK) had fungicidal and insecticidal activities, and its toxicity was bearable for the environment. We described the practical synthesis of HK-K salt. According to the GB/T18261-2000 and LY/T1283-1998, wood preservative performance of HK-K salt was tested. The results showed that the best inhibitory concentration of HK-K salt was 50 mg/L, for which the prevention effectiveness on mold is better, the killed value is between 0 and 1, and the corrosion-resistant for wood-rotting fungi is grade A.     

A critical review on the application of biochar in environmental pollution remediation: Role of persistent free radicals (PFRs)

Biochar as an emerging carbonaceous material has exhibited a great potential in environmental application for its perfect adsorption ability. However, there are abundant persistent free radicals (PFRs) in biochar, so the direct and indirect PFRs-mediated removal of organic and inorganic contaminants by biochar was widely reported. In order to comprehend deeply the formation of PFRs in biochar and their interactions with contaminants, this paper reviews the formation mechanisms of PFRs in biochar and the PFRs-mediated environmental applications of biochar in recent years. Finally, future challenges in this field are also proposed. This review provides a more comprehensive understanding on the emerging applications of biochar from the viewpoint of the catalytic role of PFRs.     

低含液输气管道内积液特性研究现状及展望

管道的湿气输送过程是典型的低持液率气液两相流工况。从湿气输送过程积液形成的机理出发,分析了流体性质、输送条件、管道结构3类参数对积液形成的影响规律,结果表明管道倾角、管径、气液比是积液形成的主要影响因素。回顾了理论模型的发展历程并对比分析了不同模型的精确性,阐述了各稳态和瞬态模拟软件的适用范围和优缺点,介绍了超声波等无损检测技术在流型识别和积液高度检测领域的应用现状,进而分析了3种方法各自存在的不足,展望了未来的研究方向可以从多起伏大倾角粗管径室内实验工况、高精度可视化多相流模拟器以及高精度易操作非介入式检测技术开展,为集输管线的积液消除和管线长周期安全运行发挥关键支撑作用。     

Bioaccumulation and effects of sediment-associated gold- and graphene oxide nanoparticles on Tubifex tubifex

With the development of nanotechnology,gold(Au) and graphene oxide(GO) nanoparticles have been widely used in various fields,resulting in an increased release of these particles into the environment.The released nanoparticles may eventually accumulate in sediment,causing possible ecotoxicological effects to benthic invertebrates.However,the impact of Au-NPs and GO-NPs on the cosmopolitan oligochaete,Tubifex tubifex,in sediment exposure is not known.Mortality,behavioral impact(GO-NP and Au-NP) and uptake(only Au-NP) of sediment-associated Au-NPs(4.9±0.14 nm) and GO-NPs(116±0.05 nm) to T.tubifex were assessed in a number of 5-day exposure experiments.The results showed that the applied Au-NP concentrations(10 and 60 μg Au/g dry weight sediment) had no adverse effect on T.tubifex survival,while Au bioaccumulation increased with exposure concentration.In the case of GO-NPs,no mortality of T.tubifex was observed at a concentration range of 20 and180 μg GO/g dry weight sediment,whereas burrowing activity was significantly reduced at 20 and 180 μg GO/g dry weight sediment.Our results suggest that Au-NPs at 60 μg Au/g or GO-NPs at 20 and 180 μg GO/g were detected by T.tubifex as toxicants during short-term exposures.