Browsing by Author "Cui, Jian"

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    Migration and emission of mercury from circulating fluidized bed boilers co-firing petroleum coke and coal
    (Elsevier, 2017-12-01) Cui, Jian; Duan, Lunbo; Jiang, Ying; Zhao, Changsui; Anthony, Edward J.
    The migration and emission of mercury (Hg) were studied for three 410 t/h circulating fluidized bed (CFB) boilers co-firing petroleum coke and coal. Both the Ontario Hydro Method (OHM) and US Environmental Protection Agency (EPA) Method 30B were employed to sample gas phase emissions of mercury from the flue gas, and to compare the agreement for these different measurement methods in industrial application. Concurrent with flue gas sampling, solid and liquid samples including fuel, bottom ash, fly ash and gypsum, wastewater, etc., were also collected to determine the total mass balance and map the mercury migration from the power plant. The results showed that the mass balance rates ranged from 83.9% to 122.7%, which can be considered to be both acceptable and reliable. The vast majority of mercury emitted was distributed in the fly ash and stack gas, accounting for 61.36–67.71% and 22.22–33.35%, respectively. The total Hg concentration measured by OHM is comparable with that determined by EPA Method 30B; however, EPA Method 30B possesses advantages in terms of flexibility. The fabric filter (FF) has better Hg0 and Hg2+ removal efficiencies than the electrostatic precipitator (ESP). Because the Hg contained in the liquid waste streams greatly exceeded Chinese regulations, the main emphasis of future work should be focused on wastewater treatment. The mercury emission factors in this study are in the range of 0.69 g/TJ-0.80 g/TJ, which provides basic data for such CFB power plants in China. The CFB boilers equipped with ESP + WFGD or FF + WFGD appear to have the potential to significantly reduce Hg emission to the atmosphere.
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    Partitioning behavior of Arsenic in circulating fluidized bed boilers co-firing petroleum coke and coal
    (Elsevier, 2017-06-05) Duan, Lunbo; Cui, Jian; Jiang, Ying; Zhao, Changsui; Anthony, Edward J.
    The emission of Arsenic from coal-fired power plants has generated widespread environmental and human health concerns. This paper discusses Arsenic partitioning from three 440 t/h circulating fluidized bed (CFB) boilers co-firing petroleum coke and coal. All the boilers were equipped with electrostatic precipitator (ESP) or fabric filter (FF), and wet flue gas desulfurization (WFGD). Flue gas was sampled simultaneously both up- and down-stream of the ESP/FF and at the outlet of the WFGD based on EPA Method 29. Concurrent with flue gas sampling, feed fuel, bottom ash, ESP/FF ash, WFGD gypsum, WFGD wastewater, limestone slurry and flush water were also collected. The results show that, for three tested CFB boilers, the overall mass balance ratios of As ranged from 80.0%–114.2%, which can be considered to be acceptable and reliable. Most of the As was distributed in the bottom ash and ESP/FF ash with the values of 17.4%–37.5% and 55.6%–77.5%, respectively. Speciation analysis suggests that As5 + was the major water-soluble species in the feed fuel, bottom ash and fly ash, while As3 + was found to be the dominant species in WFGD wastewater. For three CFB boilers, the concentrations of total As in the stack emission were 0.97, 0.32 and 0.31 μg/m3, respectively. The CFB boiler equipped with ESP/FF + WFGD was shown to be able to provide good control of the emission of As emitted into the atmosphere.
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    Poly-adenine-mediated tetrahedral DNA nanostructure with multiple target-recognition sites for ultrasensitive and rapid electrochemical detection of Aflatoxin B1
    (Elsevier, 2023-10-26) Wang, Kaixuan; Zhu, Nuanfei; Li, Yumo; Zhang, Hu; Wu, Beibei; Cui, Jian; Tang, Jun; Yang, Zhugen; Zhu, Fang; Zhang, Zhen
    Tetrahedral DNA nanostructures (TDNs) are widely used in the development of electrochemical biosensors due to their structural stability, programmability, and strong interfacial orderliness. However, the complex modifications on the electrode and the single vertex target recognition of the TDNs limit their applications in electrochemical biosensing. Herein, we developed a universal detection system based on a novel polyadenine-based tetrahedral DNA nanostructure (ATDN) using Aflatoxin B1 (AFB1) as the model target for analysis. In the absence of target AFB1, the signal probes (SP) modified with ferrocene would be anchored by five aptamers on ATDN. The target capture by aptamers led to a release of SP from the electrode surface, resulting in a significant reduction of the electrochemical signal. This new nanostructure was not only dispensed with multi-step electrode modifications and strong mechanical rigidity but also had five modification sites which enhanced the detection sensitivity for the target. As a result, this biosensor shows good analytical performance in the linear range of 1 fg mL−1 to 1 ng mL−1, exhibiting a low detection limit of 0.33 fg mL−1. Satisfactory accuracy has also been demonstrated through good recoveries (95.2%–98.9%). The proposed new tetrahedral DNA nanostructure can provide a more rapid and sensitive alternative to previous electrochemical sensors based on the conventional TDN. Since DNA sequences can be designed flexibly, the sensing platform in this strategy can be extended to detect various targets in different fields.