scholarly journals Removal of Tetracycline from Wastewater Using Circulating Fluidized Bed

2020 ◽  
Vol 21 (3) ◽  
pp. 29-37
Author(s):  
Sabreen Lateef Kareem ◽  
Ahmed A Mohammed
Keyword(s):  
Fluidized Bed ◽  
Zno Nanoparticles ◽  
Circulating Fluidized Bed ◽  
Liquid Velocity ◽  
Particle Density ◽  
Airflow Rate ◽  
Velocity Correlation ◽  
Pistachio Shell ◽  
Bed Height ◽  
Adsorbent Surface

   In this study, the circulating fluidized bed was used to remove the Tetracycline from wastewater utilizing a pistachio shell coated with ZnO nanoparticles. Several parameters including, Tetracycline solution flowrate, initial static bed height, Tetracycline initial concentration and airflow rate were systematically examined to show their effect on the breakthrough curve and the required time to reach the adsorption capacity and thus draw the fully saturated curve of the adsorbent. Results showed that using ZnO nanoparticles will increase the adsorbent surface area and pores and as a result the adsorption increased, also the required time for adsorbent saturation increased and thus the removal efficiency may be achieved at minimum antibiotic flowrate, maximum bed height, higher antibiotic concentration, and higher airflow rate. Also, a minimum fluidization velocity correlation was developed in this study. This correlation was found to be a function of liquid velocity, bed height, particle size, and particle density. The results showed that circulating fluidized bed has a better performance and last more than two hours before the bed biomass exhausted in comparison with traditional fluidized bed.

scholarly journals Removal of Congo Red from Aqueous Solution by Circulating Fluidized Bed(CFB)

2021 ◽  
Vol 28 (2) ◽  
pp. 01-07
Author(s):  
Hamza Q. Ali ◽  
Ahmed A. Mohammed
Keyword(s):  
Mass Transfer ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Congo Red ◽  
Circulating Fluidized Bed ◽  
Mass Transfer Rate ◽  
Breakthrough Curves ◽  
Solution Flow Rate ◽  
Solution Flow ◽  
Bed Height

In this study circulating fluidized bed was adopted to remove of Congo Red from wastewater using Eichhornia crassipes as a adsorbent. Solution flow rate(6,12 and 18)l/hr, bed height(2,4 and 6) cm and Congo Red initaial concentration (10,25 and 50)mg/l were examined in experiments to show their effects on breakthrough curves and time required to reach the adsorbent to fully saturated curve. The mass transfer coefficient "KL"decreased with decreasing the liquid flow rate. The minimum fluidization velocities of bed found equal to 1.6, 2, 2.5 mm/s for heights of 2, 4,6 cm respectively. The increasing of the bed height will increase the contact time of the solute in the bed, and these improve the solute removal efficiency. the increasing in flow rate and initial concentration will increase the mass transfer rate.

The control of bed height and solids circulation rate in the standpipe of a cold flow circulating fluidized bed

2005 ◽  
Vol 150 (3) ◽  
pp. 176-184 ◽  
Author(s):  
Juchirl Park ◽  
Yue Huang ◽  
Richard Turton ◽  
Parviz Famouri ◽  
Edward J. Boyle
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Cold Flow ◽  
Bed Height ◽  
Solids Circulation Rate

An Experimental Comparison of a Sliding Mode Estimator to an Extended Kalman Filter Applied to a Cold Flow Circulating Fluidized Bed

2004 ◽  
Author(s):  
Juchirl Park ◽  
Edward J. Boyle ◽  
Richard Turton ◽  
Parviz Famouri
Keyword(s):  
Kalman Filter ◽  
Fluidized Bed ◽  
Extended Kalman Filter ◽  
Circulating Fluidized Bed ◽  
Sliding Mode ◽  
Initial Conditions ◽  
Department Of Energy ◽  
Experimental Comparison ◽  
Cold Flow ◽  
Bed Height

Circulating fluidized beds (CFB) have been applied to a wide variety of chemical industry processes to reduce pollution and increase efficiency. Identifying the void fractions and the bed-height in the standpipe of the CFB is required for designing a controller to improve the overall system operation. An extended Kalman filter (EKF) algorithm has been applied in order to successfully estimate the states and the bed-height of the standpipe in the cold flow circulating fluidized bed (CFCFB) at the Department of Energy, National Energy Technology Laboratory. However, for some oscillating input cases, this method does not perform well. In addition, covariance matrices Q and R need to be assumed initially and depending upon initial conditions, for some cases, the EKF behaves unstably. In this research, a sliding mode estimator (SME) is applied in order to estimate the state, and the bed-height of the standpipe in the CFCFB. The sliding mode estimator requires the proper gain for tuning in order to have proper estimations. Test results show improvement in state estimation performance of SME over EKF.

Fluidization Behavior of Mixtures of Nanoparticles in Vibrated Fluidized Beds

2012 ◽  
Vol 550-553 ◽  
pp. 2968-2971 ◽  
Author(s):  
Xi Zhen Liang ◽  
Tao Zhou ◽  
Hao Duan
Keyword(s):  
Fluidized Bed ◽  
Zno Nanoparticles ◽  
Vibration Amplitude ◽  
Fluidized Beds ◽  
Mass Ratio ◽  
Pressure Drops ◽  
Bed Height ◽  
Vibrated Fluidized Bed ◽  
Mixed Nanoparticles

The experiments of mixtures of SiO2 and ZnO nanoparticles in a vibrated fluidized bed were carried out. The effects of ratio of initial static bed height to diameter (h0/D), vibration amplitude (A), frequency (f) and mass ratio of mixed SiO2 and ZnO nanoparticles on the behavior of mixtures of SiO2 and ZnO nanoparticles were studied. The experimental results proved that the fluidization quality of mixed nanoparticles can be enhanced under h0/D=1, A=3.0 mm, f =45Hz, leading to larger bed pressure drops at low superficial gas velocities. The bed height decreases with increase in the mass ratio of ZnO component of the mixture.

scholarly journals Enhancing Photocatalytic Activity of ZnO Nanoparticles in a Circulating Fluidized Bed with Plasma Jets

Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 77
Author(s):  
Shiwei Ma ◽  
Yunyun Huang ◽  
Ruoyu Hong ◽  
Xuesong Lu ◽  
Jianhua Li ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Fluidized Bed ◽  
Zno Nanoparticles ◽  
Circulating Fluidized Bed ◽  
Treatment Time ◽  
Degradation Mechanism ◽  
Aqueous Media ◽  
Degradation Process ◽  
Plasma Jets ◽  
Hydrogen Atoms

In this work, zinc oxide (ZnO) nanoparticles were modified in a circulating fluidized bed through argon and hydrogen (Ar–H) alternating-current (AC) arc plasma, which shows the characteristics of nonequilibrium and equilibrium plasma at the same time. In addition, a circulating fluidized bed with two plasma jets was used for cyclic processing. The catalytic degradation performance on Rhodamine B (Rh B) by Ar–H plasma-modified ZnO and pure ZnO was tested in aqueous media to identify the significant role of hydrogen atoms in Rh B degradation mechanism. Meanwhile, the effects of plasma treatment time on the morphology, size and photocatalytic performance of ZnO were also investigated. The results demonstrated that ZnO after 120-min treatment by Ar–H plasma showed Rh B photocatalytic degradation rate of 20 times greater than that of pure ZnO and the reaction follows a first kinetics for the Rh B degradation process. Furthermore, the photocatalyst cycle experiment curve exhibited that the modified ZnO still displays optimum photocatalytic activity after five cycles of experiment. The improvement of photocatalytic activity and luminescence performance attributes to the significant increase in the surface area, and the introduction of hydrogen atoms on the surface also could enhance the time of carrier existence where the hydrogen atoms act as shallow donors.

Solids circulation rate and static bed height in a riser of a circulating fluidized bed

2014 ◽  
Vol 32 (2) ◽  
pp. 284-291 ◽  
Author(s):  
Daebum Cho ◽  
Jeong-Hoo Choi ◽  
Muhammad Shahzad Khurram ◽  
Sung-Ho Jo ◽  
Ho-Jung Ryu ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Circulating Fluidized Bed ◽  
Circulation Rate ◽  
Bed Height ◽  
Solids Circulation Rate

scholarly journals Enhancing Photocatalytic Activity of ZnO Nanoparticles in a Circulating Fluidized Bed with Plasma Jets

2020 ◽  
Author(s):  
Shiwei Ma ◽  
Yunyun Huang ◽  
Ruoyu Hong ◽  
Xuesong Lu ◽  
Jianhua Li
Keyword(s):  
Photocatalytic Activity ◽  
Fluidized Bed ◽  
Zno Nanoparticles ◽  
Circulating Fluidized Bed ◽  
Treatment Time ◽  
Degradation Mechanism ◽  
Aqueous Media ◽  
Degradation Process ◽  
Plasma Jets ◽  
Hydrogen Atoms

In this work, zinc oxide (ZnO) nanoparticles were modified in a circulating fluidized bed through argon and hydrogen (Ar-H) alternative-current (AC) arc plasma, which shows the characteristics of non-equilibrium and equilibrium plasma at the same time. In addition, a circulating fluidized bed with two plasma jets was used for cyclic processing. The catalytic degradation performance on Rhodamine B (Rh B) by Ar-H plasma modified ZnO and pure ZnO was tested in aqueous media to identify the significant role of hydrogen atoms in Rh B degradation mechanism. Meanwhile, the effects of plasma treatment time on the morphology, size and photocatalytic performance of ZnO were also investigated. The results demonstrated that ZnO after 20 minutes-treatment by Ar-H plasma showed Rh B photocatalytic degradation rate is ten times greater than that of pure ZnO, and the reaction follows a first-kinetics for the Rh B degradation process. Furthermore, the photocatalyst cycle experiment curve exhibited that the modified ZnO still displays optimum photocatalytic activity after five cycles of experiment. The improvement of photocatalytic activity and luminescence performance attributes to the significant increase of the surface area, and the introduction of hydrogen atoms on the surface also could enhance the time of carrier existence where the hydrogen atoms act as shallow donors.

Radial Distribution of Liquid Velocity in a Liquid-Solids Circulating Fluidized Bed

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Ying Zheng ◽  
Jesse Zhu
Keyword(s):  
Fluidized Bed ◽  
Radial Distribution ◽  
Circulating Fluidized Bed ◽  
Liquid Velocity ◽  
Circulation Rate ◽  
Liquid Transport ◽  
Solids Circulation Rate ◽  
Fluidization Regime ◽  
Radial Profiles ◽  
Radial Nonuniformity

Local liquid velocity was measured in a liquid-solid circulating fluidized bed, with a Plexiglas riser column of 7.62 cm ID and 3.0 m in height, by a dual conductivity probe, with 508 micron glass beads. The results show that radial distribution of local liquid velocity in the LSCFB is nonuniform with higher liquid velocity at the axis and lower near the wall, compared to the more uniform radial profiles in both the conventional fluidization and the dilute liquid transport regimes. The radial nonuniformity increases with increasing liquid velocity and solids circulation rate in the LSCFB. A radial nonuniformity index, proposed by Zhu and Manyele (2001), was used to quantify the extent of the radial nonuniformity under different solids circulation rates and liquid flow rates. The radial nonuniformity index is used to qualify the radial distribution of liquid velocity. RNI values in the liquid-solid circulating fluidization regime are seen to be much higher than those in both the particulate fluidization regime and the dilute liquid transport regime, indicating the nonuniform radial distribution of local liquid velocity in the LSCFB. This illustrates the use of RNI as an effective measurement of the radial distribution of liquid velocity.

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