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Two biological aerated filters (BAF) were setup for ammonia removal treatment of the circulation water in a marine aquaculture. One
of the BAFs was bioaugmented with a heterotrophic nitrifying bacterium, Lutimonas sp. H10, where the ammonia removal was not
improved and the massive inoculation was even followed by a nitrification breakdown from day 9 to 18. The nitrification was remained
stable in control BAF operated under the same conditions. Fluorescent in situ hybridization (FISH) with rRNA-targeted probes and
cultivable method revealed that Lutimonas sp. H10 almost disappeared from the bioaugomented BAF within 3 d, and this was mainly
due to the infection of a specific phage as revealed by flask experiment, plaque assay and transmission electron observation. Analyses
of 16S rRNA gene libraries showed that bacterial groups from two reactors evolved di erently and an overgrowth of protozoa was
observed in the bioaugmented BAF. Therefore, phage infection and poor biofilm forming ability of the inoculated strain are the main
reasons for bioaugmentation failure. In addition, grazing by protozoa of the bacteria might be the reason for the nitrification breakdown
in bioaugmented BAF during day 9–18. 相似文献
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海南岛地表水的区域地球化学特征及其影响因素 总被引:1,自引:1,他引:0
始于2004年的海南岛多目标生态地球化学调查,对全岛的地表水进行了区域调查取样,分析测试了24项指标(部分样品增加测试12项)。测试结果表明,大多数指标优于国家地表水环境质量标准(GB3838-2002)中III类水体水质标准,只有Hg和总氮存在区域性的超Ⅲ类水体水质。经对样品的聚类分析研究表明,全岛地表水样品主要分为4类,分别反映了地表植被、海水入侵、灌溉水田排水、矿山废水排放对地表水化学成分的控制作用。在此认识的基础上,依地表水样品所处的土地利用方式的不同,按一定顺序对样品进行编号赋值(沿海的土地视为"海洋利用方式"),该赋值与聚类分析所得到的样品类别值之间存在极显著的正相关性,相关系数达0.8280,表明海南岛的土地利用方式是控制地表水地球化学特征的关键因素,从而为海南岛地表水环境质量的保护和提高指出了方向。 相似文献
277.
采用涡度相关法对青海湖东北岸地区草甸化草原生态系统的CO2 通量进行了观测,结果表明:
在生长季节(5~9 月),就日变化,08:00~19:00 为CO2 净吸收,20:00~07:00 为CO2 净排放,CO2 通量
净吸收峰值一般出现在12:00 时,7 月份12:00 时CO2 净吸收峰值为1.41 g·(m2·h)-1;就月变化,7 月
是生长季CO2 净吸收最高月份,月CO2 净吸收量达到162.70 g·m-2,整个生长季CO2 净吸收的总量达
468.07 g·m-2。非生长季节(1~4 月及10~12 月),CO2 通量日变化振幅极小,最大CO2 净排放通量出现
在3 月,为0.29 g·(m2·h)-1,除12 月和1 月各时段CO2 通量接近于零,其余月份各时段CO2 净排放在
0.02~0.29 g·(m2·h)-1;3 月是全年CO2 净排放的最高月份,全月CO2 净排放量为72.33 g·m-2,整个非生
长季CO2 净排放为319.78 g·m-2。结果表明,无放牧条件下青海湖东北岸地区草甸化草原,全年CO2
净吸收量达148.30 g·m-2,是显著的CO2 汇。 相似文献
278.
煤炭在铁路运输过程中扬尘量大,喷淋粘结剂对控制煤炭扬尘具有积极作用,能有效减少煤炭在运输过程中的损失,减轻环境污染,消除对客货列车造成的安全隐患。本文较系统地论述了目前喷淋粘结剂在运煤列车中的研究开发现状,探讨了粘结剂开发与设计的技术思路和研究方向。 相似文献
279.
QIN Xiaofei XIA Xijuan LI Yan ZHAO Yaxian YANG Zhongzhi FU Shan TIAN Mi ZHAO Xingru QIN Zhanfen XU Xiaobai YANG Yongjian 《环境科学学报(英文版)》2009,21(12)
To understand potential ecotoxicological effects of electrical and electronic equipment waste (e-waste) recycling and polybrominated diphenyl ethers (PBDEs) bioaccumulation in loaches, a semi-field experiment using Chinese loach (Misgurnus anguillicaudatus) as experimental fish was performed. Larval loaches were kept into net-cage for three months in an e-wastes recycling site and a reference site in Southeastern China. There was significant difference of the survival rate between the loaches from the e-wastes recycling site (27%, 19/70) and from reference site (70%, 49/70). Histopathological responses were also found in all the livers examined in loaches from the e-wastes recycling site. These results showed that mixed pollutants resulted from e-wastes recycling led to ecotoxicological effects on loaches. The bioaccumulation of polybrominated diphenyl ethers (PBDEs), the main pollutants in e-waste, in loaches was also studied in this e-wastes recycling site, the mean concentrations of total PBDEs in sediment was 6726.17 ng/g wet weight and in water samples was 4.08 ng/L (dissolved phase). BDE209 was the dominant congener in sediment and with relatively high concentration in water. Relatively low concentration of BDE209 (less than 0.01% of total PBDEs) and high concentration of BDE47 (up to 39.34% of total PBDEs) were detected in loaches. 相似文献
280.
Characterization of organic matter in total suspended particles by
thermodesorption and pyrolysis-gas chromatography-mass spectrometry 总被引:1,自引:0,他引:1
ZHAO Jinping PENG Ping’an SONG Jianzhong MA Shexi SHENG Guoying FU Jiamo 《环境科学学报(英文版)》2009,21(12):1658-1666
The organic matter in tropospheric aerosol plays an important role in atmospheric physical and chemical processes. The bulk of
organic matter, representing a significant proportion of the total suspended particulate (TSP) mass, is bound to polymeric material
whose structure and properties are largely unknown. Here we used thermodesorption gas chromatography/mass spectrometry (Td-
GC/MS) to study organic compounds of low molecular mass and pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) to
characterize the chemical structure of macromolecules in TSP samples collected in di erent seasons from di erent sites in Guangzhou.
n-Alkanes, fatty acids and nitriles were the predominant compounds in the thermodesorption products, whereas aromatics, fatty acids,
nitriles and n-alkanes/alkenes were the major compounds in the pyrolysates. The results indicated that aromatics were main units in
macromolecules. The fatty acids and nitriles formed from carboxylic ammonium salts were detected in both thermodesorption products
and pyrolysates at a certain concentration, indicating the importance of these compounds in TSP formation. The TSP source mainly
determined the occurrence of compounds in samples from urban, suburban and forest sites, whereas the TSP source and formation
process maybe controlled the seasonal variation in compounds detected. High levels of nitriles in summer samples from suburban and
forest sites coincide with the release of ammonium from the land and of fatty acids from vegetation at these sites. 相似文献