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991.
•Phages can be better indicators of enteric viruses than fecal indicator bacteria. •Multiple phages should be added to the microbial source tracking toolbox. •Engineered phage or phage cocktail can effectively target resistant bacteria. •In phage use, phage-mediated horizontal gene transfer cannot be ignored. •More schemes are needed to prevent phage concentration from decreasing. Wastewater is a breeding ground for many pathogens, which may pose a threat to human health through various water transmission pathways. Therefore, a simple and effective method is urgently required to monitor and treat wastewater. As bacterial viruses, bacteriophages (phages) are the most widely distributed and abundant organisms in the biosphere. Owing to their capacity to specifically infect bacterial hosts, they have recently been used as novel tools in water pollution control. The purpose of this review is to summarize and evaluate the roles of phages in monitoring pathogens, tracking pollution sources, treating pathogenic bacteria, infecting bloom-forming cyanobacteria, and controlling bulking sludge and biofilm pollution in wastewater treatment systems. We also discuss the limitations of phage usage in water pollution control, including phage-mediated horizontal gene transfer, the evolution of bacterial resistance, and phage concentration decrease. This review provides an integrated outlook on the use of phages in water pollution control.  相似文献   
992.
Surface ozone concentrations in Xi'an, China were monitored from March 23, 2008 to January 12, 2009 using the Model ML/EC9810 ozone analyzer. The daily average O(3) ranged from <1 ppb to 64.2 ppbv with an annual average of 16.0 ppbv. The seasonal average of O(3) in summer (32.5 ppbv) was more than 10 times higher than that in winter (3.0 ppbv). A significant positive correlation was found between ozone concentration and ambient temperature, indicating that the intensity of solar radiation was one of the several major factors controlling surface ozone production. Using the NOAA HYSPLIT 4 trajectory model, the three longest O(3) pollution episodes were found to be associated with the high biogenic volatile organic carbon (BVOC) emissions from the vegetation of Qinling Mountains. No significant weekday and weekend difference in O(3) levels was detected due to the non-significant change in NO(x) emissions. O(3) depletion by NO emission directly emitted from vehicles, low oxygenated VOC concentrations, and low-level solar radiation caused by high aerosol loading all contributed to the low levels of O(3) found in Xi'an compared to other cities and rural areas.  相似文献   
993.
● Adsorption of environmental deoxyribonucleic acid on biochar was studied. ● π−π interaction and electrostatic repulsion worked in the adsorption. ● Thermodynamics indicated the adsorption was spontaneous and endothermic. Environmental deoxyribonucleic acid (eDNA), which includes antibiotic resistance genes, is ubiquitous in the environment. The interactions between eDNA and biochar, a promising material widely used in soil amendment and water treatment, greatly affect the environmental behavior of eDNA. Hitherto few experimental evidences are available yet, especially on the information of thermodynamics and energy distribution to explains the interactions between biochar and eDNA. This study investigated the adsorption of herring sperm DNA (hsDNA) on pine sawdust biochar, with a specific emphasis on the adsorption thermodynamics and site energy distribution. The adsorption of hsDNA on biochar was enhanced by an increase in the pyrolysis and adsorption temperatures. The higher surface area, stronger π−π interaction, and weaker electrostatic repulsion between hsDNA and biochars prepared at high pyrolysis temperatures facilitated the adsorption of hsDNA. The thermodynamics indicated that the adsorption of hsDNA on biochar was spontaneous and endothermic. Therefore, higher temperature was beneficial for the adsorption of hsDNA on biochar; this was well explained by the increase in E* and F(E*) with the adsorption temperature. These results are useful for evaluating the migration and transformation of eDNA in the presence of biochar.  相似文献   
994.
茉莉酸受体蛋白COI1(coronatine insensitive 1)是茉莉酸信号转导途径的重要组成部分,为鉴定分析茶树茉莉酸受体COI1基因家族,预测其潜在的分子功能,了解茉莉酸受体COI1基因在乌龙茶加工中应答胁迫的分子机制,利用生物信息学方法对茶树茉莉酸受体COI1进行家族成员鉴定,氨基酸序列、结构域、基因结构、进化分析以及启动子顺式元件分析,结合实时荧光定量分析CsCOI1基因在乌龙茶加工中的表达.结果显示,茶树茉莉酸受体CsCOI1家族有两个成员,均含有F-box和富亮氨酸重复序列(LRRs)两个结构域;单子叶、双子叶的COI1蛋白各聚一支,且与蜜柑进化关系较近;茶树COI1基因家族两个成员均含有3个内含子,启动子顺势元件主要有胁迫响应元件、激素响应元件以及光响应元件;转录组数据说明茶树CsCOI1基因具有较强的组织表达差异性.实时荧光定量分析表明,CsCOI1a基因在室内萎凋后表达显著上调,且15 min、30 min日光萎凋后CsCOI1b基因的表达水平显著上调,同时茉莉酸含量发生显著变化.本研究推测CsCOI1基因可能通过茉莉酸信号转导途径参与乌龙茶加工中萎凋的胁迫响应过程,该结果可为乌龙茶加工品质调控奠定基础.(图8表2参30)  相似文献   
995.
This paper reviews the progress in climate change adaptation (CCA) policies both under the United Nations Framework Convention on Climate Change (UNFCCC) and in major regions and countries, including the EU and its major member countries, the influential developed countries in the Asia-Pacific region, the emerging economies and the least developed countries (LDCs). The progress made in China in CCA policies is also reviewed and compared with that in other countries. Finally, good international practices are proposed for China’s policy development. It is found that adaptation has been given the same priority as mitigation since the twenty-first century with regard to climate change-related actions. The topics related to adaptation in the international climate change negotiations under the UNFCCC have evolved from mechanisms for finance and technology development and transfer exclusively in the early stages to implementation of practical adaptation programs and actions. Since 2006, major developed and developing countries have frequently set forward specific CCA policies or general climate change policies involving adaptation in the form of laws, frameworks, strategies, and plans. The LDCs have also been working on National Adaptation Programmes of Action and subsequent National Adaptation Plans with the support from the financial mechanisms under the UNFCCC. Therefore, globally, it has become a common practice to develop national or regional policies to plan and guide CCA actions. China has established climate change policies involving adaptation at the national, regional, and sectorial levels since 2007. However, these policies have strong limitations in their knowledge base, strategic positioning, contents, and implementation mechanisms, e.g. lack of a sound knowledge base, an international perspective, clear responsibilities for policy implementation, and appropriate monitoring and evaluation mechanisms. It is recommended that China should further strengthen its technical capabilities in climate change projections as well as impact, vulnerability, and risk assessment, and develop methodologies and techniques for the preparation, impact assessment and implementation of CCA policies. Furthermore, future CCA strategies or plans should be developed with an emphasis on China’s vision and strategic position on the world stage.  相似文献   
996.
滇池底泥微生物菌群对微囊藻毒素的生物降解   总被引:9,自引:0,他引:9  
采用滇池水华蓝藻中提取提纯的微囊藻毒素(microcystins,MCs)作为微生物生长的碳源和氮源,从长期暴露于蓝藻水华的滇池底泥中,通过从含低浓度到高浓度MCs的逐步培养驯化,获得了高效降解MCs的微生物混合菌群,在初始MC-RR和LR浓度大约分别为50mg/L和30mg/L下,3d内可将MCs全部降解。进一步活性研究显示,不同含碳和含氮化合物虽然能够促进混合微生物菌群的生长,但对降解MCs却无明显的促进作用,说明MCs既可以作为微生物生长的碳源,又可以作为微生物生长的氮源,在富含有机物的天然水体中并不一定能够促进微生物对MCs的生物降解。  相似文献   
997.
采用日本大阪煤气公司先进的湿式催化氧化技术及其 2 0 0 L/ d小型工业试验装置对高浓度焦化废水、造纸黑液 (原水CODCr分别为 1180 0和 5 0 0 0 0 mg/ L )进行处理试验 ,结果 CODCr去除速率分别达到 5 40 mg/ ( L· min)和 2 412 mg/ ( L· m in)。应用国产化湿式催化氧化技术和 2 0 m3/ d工业装置对同样两种高浓度工业废水进行处理 ,结果 CODCr和 NH3-N的去除率均达 99%以上 ,并使废水经处理后连续稳定地达标排放 ,具有较好的经济效益  相似文献   
998.
同分异构体喹啉和异喹啉的缺氧降解性能比较   总被引:3,自引:0,他引:3  
研究了同分异构体的含氮杂环化合物喹啉和异喹啉在缺氧条件下的降解情况,发现两者表现出不同的缺氧降解特性。喹啉可以在缺氧条件下得到有效降解,其缺氧降解的最佳碳氮比为8。在最佳碳氮比条件下,喹啉的缺氧降解过程符合一级动力学规律,在其降解过程中首先以硝酸盐为电子受体,当硝酸盐氮浓度为零时,亚硝酸盐氮浓度达到最高,此后喹啉的降解主要以亚硝酸盐为电子受体,并和亚硝酸盐氮同时达到最低浓度。异喹啉对硝酸盐的利用甚微,其降解主要表现为厌氧降解特征,降解过程符合零级动力学规律。  相似文献   
999.
1000.
乳状液膜法迁移及分离铬(Ⅵ)的研究   总被引:6,自引:0,他引:6  
本文采用以叔胺N7301为流动载体、兰113A为表面活性剂、煤油为膜溶剂、NaOH作内相试剂的乳状液膜体系迁移分离铬(Ⅵ).研究了其迁移机理,确定了适宜制乳、迁移分离及破乳等有关条件,实验表明,不同浓度的含铬(Ⅵ)水样经液膜处理后,其含铬(Ⅵ)量均降至0.5μg·ml~(-1)以下,低于国家排放标准.  相似文献   
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