scholarly journals ADSORPTION OF FLUORIDE FROM INDUSTRIAL WASTEWATER IN FIXED BED COLUMN USING JAVA PLUM (SYZYGIUM CUMINI)

Author(s):  
Tej Pratap Singh ◽  
Sanjay Ghosh ◽  
Majumder Cb

ABSTRACTObjective: The quality of drinking water is important for public safety and quality of life. Thus, providing every person on earth safe drinking waterseems to be the biggest challenge in front of mankind. For this purpose, here we have investigated the fluoride removal capacity of java plum.Methods: In this study, removal of fluoride from industrial wastewater using fixed-bed reactor adsorption techniques by java plum seed (Syzygiumcumini) was investigated. Fixed-bed column experiments were carried out for different bed depths, influent fluoride concentrations, and various flowrates. The Thomas model and bed depth service time model were applied to the experimental results. Both model predictions verify the experimentaldata for all the process parameters studied, indicating that the models were suitable for java plum (S. cumini) seeds (Biosorbent) fix-bed columndesign.Results: The empty bed residence time (EBRT) model optimizes the EBRT, and the Thomas model showed that the adsorption capacity is stronglydependent on the flow rate, initial fluoride concentration, and bed depth and is greater under conditions of a lower concentration of fluoride, lowerflow rate, and higher bed depth.Conclusion: The experimental results were encouraging and indicate that java plum (S. cumini) seed is a feasible option to use as a biosorbent toremove fluoride in a fixed bed adsorption process.Keywords: Adsorption, Column experiment, Thomas model, Empty bed residence time, Java plum.

2021 ◽  
Vol 11 (2) ◽  
pp. 682
Author(s):  
Gabriele Seitz ◽  
Farid Mohammadi ◽  
Holger Class

Calcium oxide/Calcium hydroxide can be utilized as a reaction system for thermochemical heat storage. It features a high storage capacity, is cheap, and does not involve major environmental concerns. Operationally, different fixed-bed reactor concepts can be distinguished; direct reactor are characterized by gas flow through the reactive bulk material, while in indirect reactors, the heat-carrying gas flow is separated from the bulk material. This study puts a focus on the indirectly operated fixed-bed reactor setup. The fluxes of the reaction fluid and the heat-carrying flow are decoupled in order to overcome limitations due to heat conduction in the reactive bulk material. The fixed bed represents a porous medium where Darcy-type flow conditions can be assumed. Here, a numerical model for such a reactor concept is presented, which has been implemented in the software DuMux. An attempt to calibrate and validate it with experimental results from the literature is discussed in detail. This allows for the identification of a deficient insulation of the experimental setup. Accordingly, heat-loss mechanisms are included in the model. However, it can be shown that heat losses alone are not sufficient to explain the experimental results. It is evident that another effect plays a role here. Using Bayesian inference, this effect is identified as the reaction rate decreasing with progressing conversion of reactive material. The calibrated model reveals that more heat is lost over the reactor surface than transported in the heat transfer channel, which causes a considerable speed-up of the discharge reaction. An observed deceleration of the reaction rate at progressed conversion is attributed to the presence of agglomerates of the bulk material in the fixed bed. This retardation is represented phenomenologically by mofifying the reaction kinetics. After the calibration, the model is validated with a second set of experimental results. To speed up the calculations for the calibration, the numerical model is replaced by a surrogate model based on Polynomial Chaos Expansion and Principal Component Analysis.


1991 ◽  
Vol 23 (7-9) ◽  
pp. 1319-1326 ◽  
Author(s):  
I. E. Gönenç ◽  
D. Orhon ◽  
B. Beler Baykal

Two basic phenomena, reactor hydraulics and mass transport through biofilm coupled with kinetic expressions for substrate transformations were accounted for in order to describe the soluble COD removal mechanism in anaerobic fixed bed reactors. To provide necessary verification, experimental results from the long term operation of the pilot scale anaerobic reactor treating molasses wastewater were used. Theoretical evaluations verified by these experimental studies showed that a bulk zero-order removal rate expression modified by diffusional resistance leading to bulk half-order and first-order rates together with the particular hydraulic conditions could adequately define the overall soluble COD removal mechanism in an anaerobic fixed bed reactor. The experimental results were also used to determine the kinetic constants for practical application. In view of the complexity of the phenomena involved it is found remarkable that a simple simulation model based on biofilm kinetics is a powerful tool for design and operation of anaerobic fixed bed reactors.


2012 ◽  
Vol 1 (3) ◽  
pp. 81 ◽  
Author(s):  
A Buasri ◽  
B Ksapabutr ◽  
M Panapoy ◽  
N Chaiyut

: The continuous production of ethyl ester was studied by using a steady-state fixed bed reactor (FBR). Transesterification of palm stearin (PS) and waste cooking palm oil (WCPO) with ethanol in the presence of calcium oxide impregnated palm shell activated carbon (CaO/PSAC) solid catalyst was investigated. This work was determined the optimum conditions for the production of ethyl ester from PS and WCPO in order to obtain fatty acid ethyl ester (FAEE) with the highest yield. The effects of reaction variables such as residence time, ethanol/oil molar ratio, reaction temperature, catalyst bed height and reusability of catalyst in a reactor system on the yield of biodiesel were considered. The optimum conditions were the residence time 2-3 h, ethanol/oil molar ratio 16-20, reaction temperature at 800C, and catalyst bed height 300 mm which yielded 89.46% and 83.32% of the PS and WCPO conversion, respectively. CaO/PSAC could be used repeatedly for 4 times without any activation treatment and no obvious activity loss was observed. It has potential for industrial application in the transesterification of triglyceride (TG). The fuel properties of biodiesel were determined. Keywords: biodiesel, calcium oxide, ethyl ester, fixed bed reactor, palm shell activated carbon


2019 ◽  
Vol 120 ◽  
pp. 03003
Author(s):  
Huang-Mu Lo ◽  
Kae-Long Lin ◽  
Min-Hsin Liu ◽  
Hsung-Ying Chiu ◽  
Fang-Cheng Lo

Heavy metals from the electroplating wastewater might cause environmental pollution if not well treated. Generally, carbon adsorption might be used for the final step for further trace metals removal. This study investigated the heavy metal Cu adsorption in the fixed bed column with 1, 10 and 100 mg/L influent concentration. Results showed that KAB decreased as influent Cu concentration increased from 1 to 100 mg/L while N0 increased as influent concentration increased from 1 to 100 mg/L as can be found in Adams-Bohart model. R2 was found between 0.8579 and 0.9182. In Thomas model. KTH and q0 showed the similar trend as KAB and N0 in the Adams-Bohart model. KTH decreased as influent Cu concentration increased from 1 to 100 mg/L. q0 increased as influent Cu concentration increased from 1 to 100 mg/L. R2 of regression model was found between 0.9065 and 0.9836. In Yoon-Nelson model. KYN increased as influent Cu concentration increased from 1 to 100 mg/L while τ decreased as influent Cu concentration increased from 1 to 100 mg/L. Results showed that the three models of Adams-Bohart model, Thmoas model and The Yoon-Nelson model were suitable for the description of Cu adsorption by activated carbon.


2014 ◽  
Vol 1008-1009 ◽  
pp. 252-256
Author(s):  
Wipawan Sangsanga ◽  
Jin Xiao Dou ◽  
Zhe Lei Tong ◽  
Jiang Long Yu

The catalytic effects of Zn on the yield of the gaseous products during steam gasification of lignite char were investigated by using a fixed-bed reactor. The gas composition was measured using a gas chromatography (GC). The experimental results show that Zn has catalytic effects on steam gasification and increased the yield of H2. There was an optimum content of Zn implanted into the coal above which zinc does not show further catalytic activity.


Author(s):  
Meena Chakraborty ◽  
Madhurima Pandey ◽  
Piyushkant Pandey

Abstract A continuous adsorption study in a fixed-bed column was carried out by using Tinospora cordifolia as an adsorbent for the removal of fluoride from aqueous solution. The effect of flow rate, influent fluoride concentration and bed depth on the adsorption characteristics of adsorbent was investigated at pH 7. The dependencies of breakthrough curves on these parameters were confirmed from the data obtained. Modeling of data was done. Thomas, Yoon–Nelson and Adams–Bohart models were applied to experimental data to predict the breakthrough curves. These kinetic models were helpful to determine the characteristic parameters of column designing for defluoridation on a large scale. Thomas and Yoon-Nelson models were found to be more suitable for the description of the breakthrough curve than the Adams–Bohart model in the present study. It was concluded that the Tinospora cordifolia-packed column can be used for effective defluoridation of water.


Sign in / Sign up

Export Citation Format

Share Document