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191.
192.
Christine Susan Fagnant Alexandra Lynn Kossik Nicolette Angela Zhou Liliana Sánchez-Gonzalez Jill Christin Falman Erika Karen Keim Yarrow Linden Alana Scheibe Kilala Sayisha Barnes Nicola Koren Beck David S. Boyle John Scott Meschke 《Food and environmental virology》2017,9(4):383-394
Environmental surveillance of poliovirus (PV) and other non-enveloped viruses can help identify silent circulation and is necessary to certify eradication. The bag-mediated filtration system is an efficient method to filter large volumes of environmental waters at field sites for monitoring the presence of viruses. As filters may require long transit times to off-site laboratories for processing, viral inactivation or overgrowth of bacteria and fungi can interfere with virus detection and quantification (Miki and Jacquet in Aquatic Microb Ecol 51(2):195–208, 2008). To evaluate virus survival over time on ViroCap? filters, the filters were seeded with PV type 1 (PV1) and/or MS2 and then dosed with preservatives or antibiotics prior to storage and elution. These filters were stored at various temperatures and time periods, and then eluted for PV1 and MS2 recovery quantification. Filters dosed with the preservative combination of 2% sodium benzoate and 0.2% calcium propionate had increased virus survival over time when stored at 25 °C, compared to samples stored at 25 °C with no preservatives. While elution within 24 h of filtration is recommended, if storage or shipping is required then this preservative mixture can help preserve sample integrity. Addition of an antibiotic cocktail containing cephapirin, gentamicin, and Proclin? 300 increased recovery after storage at 4 and 25 °C, when compared to storage with no antibiotics. The antibiotic cocktail can aid sample preservation if access to appropriate antibiotics storage is available and sample cold chain is unreliable. This study demonstrated that the use of preservatives or antibiotics is a simple, cost-effective method to improve virus detection from ViroCap cartridge filters over time. 相似文献
193.
~(129)I由于具有较长半衰期,为2 Ma—80 Ma的地质定年提供了可能,因此,近几十年来,~(129)I定年的关键参数"初始值"受到了学术界关注。海洋系统中~(129)I初始值研究已较为成熟,并得到广泛认可和应用。陆地环境的认知有限,但一定程度上暗示了海陆间可能存在差异。由于环境中天然~(129)I和~(127)I来源的不同,影响地表碘同位素混合过程的环境因素是讨论陆地~(129)I初始值水平的关键,将为以后确定陆地环境的~(129)I初始值提供思路。 相似文献
194.
适用于中国燃煤电厂的汞监测及排放控制技术 总被引:1,自引:1,他引:0
随着GB 13223—2011《火电厂大气污染物排放标准》的颁布,汞排放问题正式列入了控制目标,这必将对燃煤电厂的环保设施提出新的更高的要求。在综述国外汞监测技术的前提下,总结脱硫脱硝污染物监测的经验,针对中国的具体情况分析了新形势下我国燃煤电厂汞监测技术的发展方向和关键技术的开发重点。同时分析了在最大化地利用燃煤电厂现有环保设施和设备的情况下,如何开发在今后一段时期内最适宜在我国广泛应用的汞排放控制技术,也对国内今后的政策发展进行了预测。 相似文献
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Utilizing surfactants to control the sorption, desorption, and biodegradation of phenanthrene in soil-water system 总被引:1,自引:0,他引:1
An integrative technology including the surfactant enhanced sorption and subsequentdesorption and biodegradation of phenanthrene in the soil-water system was introduced and tested. For slightly contaminated agricultural soils, cationic-nonionic mixed surfactant- enhanced sorption of organic contaminants onto soils could reduce their transfer to plants, therefore safe-guarding agricultural production. After planting, residual surfactants combined with added nonionic surfactant could also promote thedesorption and biodegradation of residual phenanthrene, thus providing a cost-effective pollution remediation technology.0ur results showed that the cationic-nonionic mixed surfactantsdodecylpyridinium bromide (DDPB) and Triton X-100 (TX100) significantly enhanced soil retention of phenanthrene. The maximum sorption coefficient Kd* of phenanthrene for contaminated soils treated by mixed surfactants was about24.5 times that of soils without surfactant (Kd ) and higher than the combined effects of DDPB and TX100 individually, which was about 16.7 and 1.5 times Kd , respectively.0n the other hand, TX100 could effectively remove phenanthrene from contaminated soils treated by mixed surfactants, improving the bioavailability of organic pollutants. Thedesorption rates of phenanthrene from these treated soils were greater than 85% with TX100 concentration above2000 mg/L and approached 100% with increasing TX100 concentration. The biodegradation rates of phenanthrene in the presence of surfactants reached over 95% in30days. The mixed surfactants promoted the biodegradation of phenanthrene to some extent in 10-22days, and had no obvious impact on phenanthrene biodegradation at the end of the experiment. Results obtained from this study provide some insight for the production of safe agricultural products and a remediation scheme for soils slightly contaminated with organic pollutants. 相似文献
198.
A pilot-scale study of cryolite precipitation from high fluoride-containing wastewater in a reaction-separation integrated reactor 总被引:2,自引:0,他引:2
Fluoride removal by traditional precipitation generates huge amounts of a water-rich sludge with low quality, which has no commercial or industrial value. The present study evaluated the feasibility of recovering fluoride as low water content cryolite from industrial fluoride-containing wastewater. A novel pilot-scale reaction-separation integrated reactor was designed. The results showed that the seed retention time in the reactor was prolonged to strengthen the induced crystallization process. The particle size of cryolite increased with increasing seed retention time, which decreased the water content. The recovery rate of cryolite was above 75% under an influent fluoride concentration of 3500 mg/L, a reaction temperature of 50℃, and an influent flow of 40 L/hr. The cryolite products that precipitated from the reactor were small in volume, large in particle size, low in water content, high in crystal purity, and recyclable. 相似文献
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Effects of physical and chemical characteristics of surface sediments in the formation of shallow lake algae-induced black bloom 总被引:12,自引:0,他引:12
Qiushi Shen Cheng Liu Qilin Zhou Jingge Shang Lei Zhang ChengXin Fan 《环境科学学报(英文版)》2013,25(12):2353-2360
Surface sediments are closely related to lake black blooms. The dissolved oxygen (DO) distribution and its penetration depth in surface sediments as well as the migration and transformation of redox sensitive elements such as Fe and S at the sediment-water interface are important factors that could influence the formation of the black bloom. In this study, dredged and undredged sediment cores with different surface properties were used to simulate black blooms in the laboratory. The Micro Profiling System was employed to explore features of the DO and ∑H2S distribution at the sediment-water interface. Physical and chemical characteristics in sediments and pore waters were also analyzed. The results showed that sediment dredging effectively suppressed the black blooms. In the undredged treatment, DO penetration depth was only 50 μm. Fe^2+ concentrations, ∑H2S concentrations, and ∑H2S production rates were remarkably higher in surface sediments and pore waters compared to control and dredged treatments. Furthermore, depletion of DO and accumulation of Fe^2+ and ∑H2S in surface sediments and pore waters provided favorable redox environments and necessary material sources for the blooms. The study results proved that physical and chemical characteristics in surface sediments are important factors in the formation of the black bloom, and could provide scientific guidance for emergency treatment and long-term pre-control of black blooms. 相似文献