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781.
782.
The growth, cellular total lipids, bioaccumulation amount, and bioaccumulation factors (BAFs) of 2,4,4 ′ -tribromodiphenyl ether (BDE28), 2,2 ′ ,4,4 ′ -tetrabromodiphenyl ether (BDE47), and 2,2 ′ ,4,4 ′ ,5-pentabromodiphenyl ether (BDE99) in a semi-continuous culture of Prorocentrum donghaiense were studied in relation to nitrate (0, 128, and 512 μmol/L) and phosphate (0, 8, and 32 μmol/L) concentrations. The BDE28, BDE47, and BDE99 content per cell under 0 μmol N/L were 3.77 × 10 6 , 3.95 × 10 6 , and 4.32 × 10 6 ng/cell, respectively, which were significantly higher than those under 128 and 512 μmol N/L. A nearly 5-fold increase in polybrominated diphenyl ether (PBDE) content per algal cell was found between 0 and 8 μmol P/L and between 8 and 32 μmol P/L. With increasing N and P concentrations, the PBDE content per volume of algal culture and the accumulation percentage of available PBDEs declined slightly. The BAFs for the PBDEs based on lipids showed that the logBAF lip under 0 μmol N/L was higher than those under 128 and 512 μmol N/L. The logBAF lip under 0 μmol P/L was higher than that under 8 μmol P/L but lower than that under 32 μmol P/L. Correlation analysis indicated a significant negative correlation between nutrient concentration and cellular total lipids, as well as the PBDE content per cell. The results indicate that different N and P concentrations change the total lipids content of P. donghaiense, thereby resulting in varying PBDE accumulation. 相似文献
783.
2株好氧反硝化菌的筛选及其强化贫营养生物膜脱氮效果 总被引:1,自引:1,他引:0
经富集培养、BTB培养基初筛与反硝化能力测定,从城市污水处理厂活性污泥中筛选得到2株好氧反硝化细菌.通过16S rDNA同源性分析对2株菌进行鉴定;并将这2菌株接种到贫营养生物膜体系中以探究它们对系统总氮的去除能力的强化.结果表明,这2株菌分别属于Pseudomonas aeruginosa和Pseudomonas putida,2株好氧反硝化菌单独存在时,对模拟废水的TN去除率分别达78%和82%;2株细菌强化后的生物膜系统对TN去除率达68%和64%,较非强化对照系统分别提高47%和43%,且NH4+-N去除率均接近100%.说明这2株好氧反硝化细菌具有较强的反硝化能力,并能够有效强化生物膜在贫营养条件下的反硝化能力,并且不会抑制生物膜硝化能力,可实现生物膜系统同步硝化反硝化. 相似文献
784.
1株分离自煤矿废水的铁硫氧化细菌LY01的鉴定及其氧化特性研究 总被引:1,自引:0,他引:1
从贵州省某煤矿废水中分离出1株嗜酸性的铁硫氧化细菌菌株LY01,经过对该菌株的形态特征、理化特征检测及16S rRNA序列分析,初步鉴定菌株LY01为嗜酸性氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans).在无机盐培养液中菌株LY01可以从氧化Fe2+、单质硫(S0)及黄铁矿(FeS2)获得能量生长,对Fe2+的氧化速率最快,反应30 h即可将44.2 g.L-1的FeSO4.7H2O完全氧化,菌体细胞达到4.2×107个.mL-1;反应21 d可将溶液中10 g.L-1含量的S0氧化6.7%,溶液中SO24-浓度达2 001 mg.L-1,菌体细胞达到8.9×107个.mL-1;反应20 d可将溶液中30 g.L-1含量的FeS2氧化10%,溶液中SO24-浓度达4 443 mg.L-1,菌体细胞达到3.4×108个.mL-1.研究重金属离子Ni2+、Pb2+对菌株LY01氧化FeS2活性的影响,结果发现10~100 mg.L-1的Ni2+对菌株LY01氧化FeS2活性有一定的影响,而10~100 mg.L-1Pb2+对菌株LY01氧化FeS2的活性无影响. 相似文献
785.
Three types of macromolecular organic matters (MOMs), i.e. humic acid (HA), kerogen+black carbon (KB), and black carbon (BC) were extracted from marine sediments of Xiamen Gulf, southeast of China. The chemical composition, morphological property and source of the three extractions were characterized by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS) and scanning electron microscope (SEM). The results showed that KB was the predominant fraction in MOMs, which accounted for 61.79%-89.15% of the total organic content (TOC), while HA consisted less than 5%. The relative high contents of kerogen and BC, and low contents of HA in the samples indicated that anthropogenic input might be the major source of organic matter in marine sediments near the industrial regions. The characterization of SEM, not only revealed morphological properties of the three fractions, but also allowed a better understanding of the source of MOMs. The δ 13 C values of the three fractions suggested that materials from terrestrial C 3 plants were predominant. Furthermore, the anthropogenic activities, such as the discharge of sewage, coal and biomass combustion from industry nearby and agricultural practices within drainage basin of the Jiulong River, were remarkably contributed to the variations in δ 13 C values of MOMs in the offshore marine sediments. 相似文献
786.
Three identical sequencing batch reactors (SBRs) were operated to investigate the effects of various idle times on the biological phosphorus (P) removal. The idle times were set to 3 hr (R1), 10 hr (R2) and 17 hr (R3). The results showed that the idle time of a SBR had potential impact on biological phosphorus removal, especially when the influent phosphorus concentration increased. The phosphorus removal efficiencies of the R2 and R3 systems declined dramatically compared with the stable R1 system, and the Prelease and P-uptake rates of the R3 system in particular decreased dramatically. The PCR-DGGE analysis showed that uncultured Pseudomonas sp. (GQ183242.1) and β-Proteobacteria (AY823971) were the dominant phosphorus removal bacteria for the R1 and R2 systems, while uncultured γ-Proteobacteria were the dominant phosphorus removal bacteria for the R3 system. Glycogen-accumulating organisms (GAOs), such as uncultured Sphingomonas sp. (AM889077), were found in the R2 and R3 systems. Overall, the R1 system was the most stable and exhibited the best phosphorus removal efficiency. It was found that although the idle time can be prolonged to allow the formation of intracellular polymers when the phosphorus concentration of the influent is low, systems with a long idle time can become unstable when the influent phosphorus concentration is increased. 相似文献
787.
788.
789.
以硅胶为基质的交联壳聚糖对Ni2+的吸附研究 总被引:9,自引:0,他引:9
以硅胶为基质的交联壳聚糖作为重金属Ni^2 的吸附剂,对影响该吸附Ni^2 的因素及吸附剂的再生和其吸附能力的变化,吸附机理等进行了研究。结果显示,吸附剂在一定的实验条件下对Ni^2 的最高吸附量按每克壳聚糖计可达650mg/g,且吸附平衡时间短。在柱法实验中其吸附率在99.9%以上。 相似文献
790.