scholarly journals Analysis of Packed Bed Adsorption Column with Low Cost Adsorbent for Cadmium Removal

2014 ◽  
Vol 09 (1) ◽  
Keyword(s):  
Flow Rate ◽  
Packed Bed ◽  
Second Order ◽  
Order Kinetic ◽  
Cadmium Removal ◽  
Initial Concentration ◽  
First Order ◽  
Bed Height ◽  
Solute Uptake ◽  
Kinetics Of

In the current research, removal of cadmium from the effluent by using rice husk adsorbent is studied in packed bed with respect to various parameters like initial concentration, adsorbent dose, bed height and pH. Also the solute uptake data was analyzed for first and second order kinetic equations by varying these parameters. The effect of these parameters on kinetics of solute uptake is reported. It was observed that with increase in initial concentration from 10 mg/l to 50 mg/l, the exhaustion time decreased from 830 mg/l to 570 mg/l and break point time decreased from 330 minutes to 120 minutes. Also with increase in flow rate, exhaust time and break through time decreased significantly. The alkaline conditions favoured the adsorption with optimum pH of 6.The exhaustion and break through delayed with increasing bed height. The kinetics of the cadmium removal was affected by initial concentration and flow rate. At low initial concentration, it indicated second order kinetics. There was increasing shift from second to first order with increase in initial concentration. With increase in bed height from 30 to 40 cm there was shift from second to first order but with further increase in bed height, again shift towards second order kinetics was observed. The optimum bed height, initial concentration, flow rate and pH values were 50 cm,30 mg/l, 60 ml/min and 6 respectively. The adsorption efficiency was estimated to be 69 percent for optimum values of pH, initial concentration, bed height and flow rate.

scholarly journals Packed Bed Adsorption Column Modeling for Cadmium Removal

2015 ◽  
Vol 09 (2) ◽  
Keyword(s):  
Experimental Data ◽  
Kinetic Parameters ◽  
Flow Rate ◽  
Packed Bed ◽  
Thomas Model ◽  
Cadmium Removal ◽  
Factors Affecting ◽  
Initial Concentration ◽  
Bed Height ◽  
Model Equations

Packed bed adsorption of various pollutants from effluents is efficient and cost effects method. Various factors affecting the removal percentage are initial concentration, flow rate, pH and bed height. Various models can be used to explain the packed bed adsorption. In the current work, the experimental data obtained for packed bed is fitted in the two model equations. Thomas model and Yoon Nelson model were used and the kinetic parameters were computed. Also effect of the factors like initial concentration, flow rate, pH and bed height on these kinetic parameters was studied. It was observed that these factors moderately influence the kinetic parameters. The experimental data was well described by these two models.

scholarly journals Batch and continuous fixed bed adsorption of heavy metals removal using activated charcoal from neem (Azadirachta indica) leaf powder

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Himanshu Patel
Keyword(s):  
Heavy Metals ◽  
Flow Rate ◽  
Activated Charcoal ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Column Study ◽  
Initial Concentration ◽  
Bed Height ◽  
Leaf Powder ◽  
Batch Treatment

Abstract The present investigate was intended for adsorption of heavy metals i.e. Pb, Cu, Cr, Zn, Ni and Cd onto activated charcoal prepared from neem leaf powder (AC-NLP) using batch and column studies. Batch adsorption was performed using different variables like adsorbent dose, temperature and contact duration. Thermodynamic analysis of batch treatment concluded that adsorption is thermodynamically feasible and endothermic. This adsorption followed the Pseudo second-order kinetic model derived from correlation coefficient values of chemical kinetic studies. For column study, interpretation of breakthrough curves and parameters were conducted by varying flow rate, initial concentration and bed height; and reveal that optimum conditions were lower flow rate (5 mL/min) and lower initial concentration (5 mg/L) and higher bed height (20 cm). Comparisons of batch and column study through isotherm models were evaluated and column study is more preferred than batch treatment. Maximum Thomas adsorption capacity was achieved upto 205.6, 185.8, 154.5, 133.3, 120.6, 110.9 mg/g for Pb, Cu, Cd, Zn, Ni and Cr respectively. This removal pattern is elucidated by metal ionic properties. Various adsorbing agents such as acids and bases were utilized for adsorption–desorption of AC-NLP.

Evidence for general base catalysis by protic solvents in a kinetic study of alcoholyses and hydrolyses of 1-(phenoxycarbonyl)pyridinium ions under both solvolytic and non-solvolytic conditions

2009 ◽  
Vol 74 (1) ◽  
pp. 43-55 ◽  
Author(s):  
Dennis N. Kevill ◽  
Byoung-Chun Park ◽  
Jin Burm Kyong
Keyword(s):  
Second Order ◽  
Base Catalysis ◽  
Substitution Reactions ◽  
Third Order ◽  
Methoxy Derivative ◽  
First Order ◽  
General Base ◽  
Protic Solvents ◽  
Kinetics Of ◽  
Pyridinium Ions

The kinetics of nucleophilic substitution reactions of 1-(phenoxycarbonyl)pyridinium ions, prepared with the essentially non-nucleophilic/non-basic fluoroborate as the counterion, have been studied using up to 1.60 M methanol in acetonitrile as solvent and under solvolytic conditions in 2,2,2-trifluoroethan-1-ol (TFE) and its mixtures with water. Under the non- solvolytic conditions, the parent and three pyridine-ring-substituted derivatives were studied. Both second-order (first-order in methanol) and third-order (second-order in methanol) kinetic contributions were observed. In the solvolysis studies, since solvent ionizing power values were almost constant over the range of aqueous TFE studied, a Grunwald–Winstein equation treatment of the specific rates of solvolysis for the parent and the 4-methoxy derivative could be carried out in terms of variations in solvent nucleophilicity, and an appreciable sensitivity to changes in solvent nucleophilicity was found.

Column Study for Adsorption of Methylene Blue Dye using Azadirachta indica Adsorbent

2020 ◽  
Vol 17 (4) ◽  
pp. 47-52
Author(s):  
Vibha Goswami ◽  
Renu Upadhyaya ◽  
Sumanta Kumar Meher
Keyword(s):  
Methylene Blue ◽  
Flow Rate ◽  
Azadirachta Indica ◽  
Packed Bed ◽  
Blue Dye ◽  
Feed Flow Rate ◽  
Methylene Blue Dye ◽  
Packed Bed Column ◽  
Bed Height ◽  
Percentage Removal

In this study, synthesised Azadirachta indica adsorbent was used for the removal of methylene blue dye using a packed bed column. The effect of feed flow rate, feed methylene blue dye concentration, and bed height of column on percentage removal of dye was studied. It was observed that the column bed exhausted rapidly at a higher flow rate and therefore, a breakthrough occurred faster. However, it was observed that bed exhaustion time increases on increasing the bed height from 2 to 10 inch at 10 mg/L feed dye concentration and feed flow rate of 40 ml/min. It was also found that the breakthrough curve is more dispersed and the percentage removal of dye increases on decreasing the feed methylene dye concentration from 150 to 10 mg/L. The percentage removal was found to be 96.89% at 20 ml/min of feed flow rate under 10 inch of bed height and 10 mg/L of feed dye concentration. The atomic absorption spectrophotometer and scanning electron microscope were used for estimating the effluent dye concentration from the column and morphological study, respectively.

Kinetics and Equilibrium of Radioactive Metal Adsorption onto Sugarcane Bagasse Waste: Comparison of Batch and Column Adsorption Modes

2021 ◽  
Vol 235 (3) ◽  
pp. 281-294
Author(s):  
Abida Kausar ◽  
Haq Nawaz Bhatti ◽  
Munawar Iqbal
Keyword(s):  
Sugarcane Bagasse ◽  
Flow Rate ◽  
Breakthrough Curves ◽  
Quadratic Model ◽  
Waste Biomass ◽  
Initial Concentration ◽  
Bed Height ◽  
Column Adsorption ◽  
Central Composite ◽  
Bagasse Waste

Abstract Sugarcane bagasse waste biomass (SBWB) efficacy for the adsorption of Zr(IV) was investigated in batch and column modes. The process variables i.e. pH 1–4 (A), adsorbent dosage 0.0–0.3 g (B), and Zr(IV) ions initial concentration 25–200 mg/L (C) were studied. The experiments were run under central composite design (CCD) and data was analysed by response surface methodology (RSM) methodology. The factor A, B, C, AB interaction and square factor A2, C2 affected the Zr(IV) ions adsorption onto SBWB. The quadratic model fitted well to the adsorption data with high R2 values. The effect of bed height, flow rate and Zr(IV) ions initial concentration was also studied for column mode adsorption and efficiency was evaluated by breakthrough curves as well as Bed Depth Service and Thomas models. Bed height and Zr(IV) ions initial concentration enhanced the adsorption of capacity of Zr(IV) ions, whereas flow rate reduced the column efficiency.

Degradation of Organophosphorus Pesticide in a Packed-Bed Plasma Reactor: Effects of Operating Parameters and Kinetics Study

2013 ◽  
Vol 781-784 ◽  
pp. 1637-1645 ◽  
Author(s):  
Ting Jun Ma ◽  
Yi Qing Xu
Keyword(s):  
Removal Efficiency ◽  
Flow Rate ◽  
Gas Flow ◽  
Plasma Reactor ◽  
Organophosphorus Pesticide ◽  
Packed Bed ◽  
Pulse Frequency ◽  
Gas Flow Rate ◽  
Peak Voltage ◽  
Initial Concentration

The degradation effectiveness and reaction kinetics of representative organophosphorus (OP) pesticide in a packed-bed plasma reactor have been studied. Important parameters, including peak voltage, pulse frequency, gas-flow rate, initial concentration, diameter of catalyst particles, and thickness of catalyst bed which influences the removal efficiency, were investigated. Experimental results indicated that rogor removal efficiency as high as 80% can be achieved at 35 kV with the gas flow rate of 800 mL/min and initial concentration of 11.2 mg/m3.The removal efficiency increased with the increase of pulsed high voltage, and pulse frequency, the decrease of the diameter of catalyst particles and the thickness of catalyst bed. Finally, a model was established to predict the degradation of the rogor, which generally can simulate the experimental measurements to some degree.

Kinetics of bioactive compounds in functional spice Jiangpo during thermal processing

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Xiaoyan Dai ◽  
Chenhuan Yu ◽  
Qiaofeng Wu
Keyword(s):  
Kinetic Parameters ◽  
Bioactive Compounds ◽  
Thermal Processing ◽  
Order Rate Constant ◽  
Heat Processing ◽  
Order Kinetic ◽  
Time Intervals ◽  
First Order ◽  
Order Kinetic Model ◽  
Kinetics Of

Abstract Jiangpo is an increasingly popular East Asian spice which is made from Mangnolia officinalis bark and ginger juice. Since it induces bioactive compounds decomposition and has influence on final flavor and fragrance, cooking is regarded as the key operation in preparation of Jiangpo. To evaluate the bioactive compounds content changes of Jiangpo during thermal processing, kinetic parameters including reaction order, rate constant, T1/2 and activation energy of bioactive markers namely honokiol, magnolol and curcumin were determined. Cooking was set at temperatures 60, 90 and 120 °C for selected time intervals. Results displayed the thermal kinetic characteristics of the three compounds. Thermal degradation of Honokiol and magnolol both followed first order kinetic model and the loss of curcumin fitted second order. A mathematical model based on the obtained kinetic parameters has also been developed to predict the degradation of honokiol, magnolol and curcumin in non-isothermal state. All the information in this paper could contribute necessary information for optimizing the existing heat processing of Jiangpo.

scholarly journals Kinetics of Phenolic Compounds Modification during Maize Flour Fermentation

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6702
Author(s):  
Oluwafemi Ayodeji Adebo ◽  
Ajibola Bamikole Oyedeji ◽  
Janet Adeyinka Adebiyi ◽  
Chiemela Enyinnaya Chinma ◽  
Samson Adeoye Oyeyinka ◽  
...  
Keyword(s):  
Phenolic Compounds ◽  
Phenolic Acids ◽  
Kinetic Models ◽  
Titratable Acidity ◽  
Second Order ◽  
Soluble Solids ◽  
Maize Flour ◽  
First Order ◽  
Compound Modification ◽  
Kinetics Of

This study aimed to investigate the kinetics of phenolic compound modification during the fermentation of maize flour at different times. Maize was spontaneously fermented into sourdough at varying times (24, 48, 72, 96, and 120 h) and, at each point, the pH, titratable acidity (TTA), total soluble solids (TSS), phenolic compounds (flavonoids such as apigenin, kaempferol, luteolin, quercetin, and taxifolin) and phenolic acids (caffeic, gallic, ferulic, p-coumaric, sinapic, and vanillic acids) were investigated. Three kinetic models (zero-, first-, and second-order equations) were used to determine the kinetics of phenolic modification during the fermentation. Results obtained showed that fermentation significantly reduced pH, with a corresponding increase in TTA and TSS. All the investigated flavonoids were significantly reduced after fermentation, while phenolic acids gradually increased during fermentation. Among the kinetic models adopted, first-order (R2 = 0.45–0.96) and zero-order (R2 = 0.20–0.82) equations best described the time-dependent modifications of free and bound flavonoids, respectively. On the other hand, first-order (R2 = 0.46–0.69) and second-order (R2 = 0.005–0.28) equations were best suited to explain the degradation of bound and free phenolic acids, respectively. This study shows that the modification of phenolic compounds during fermentation is compound-specific and that their rates of change may be largely dependent on their forms of existence in the fermented products.

scholarly journals KINETICS OF OZONE REACTIONS WITH ADENINE AND CYTOSINE IN AQUEOUS SOLUTIONS

2020 ◽  
Vol 63 (10) ◽  
pp. 17-22
Author(s):  
Aigul A. Maksyutova ◽  
Elvina R. Khaynasova ◽  
Yuriy S. Zimin
Keyword(s):  
Aqueous Solutions ◽  
Rate Constants ◽  
Correlation Coefficients ◽  
Activation Parameters ◽  
Second Order ◽  
Order Kinetic ◽  
Temperature Dependences ◽  
Ozone Reactivity ◽  
Kinetics Of ◽  
Ozone Reactions

The ultraviolet spectroscopy method has been applied to study the kinetics of the ozone reactions with nitrogenous bases (NB), namely adenine and cytosine in aqueous solutions. At the first research stage, the range of NB working concentrations has been determined. It was found that linear dependences between optical densities and concentrations of nitrogenous bases aqueous solutions are quite reliable, with correlation coefficients r ≥ 0.998, are satisfied up to [NB] = 2.3 ∙ 10–4 mol/l. According to the Bouguer-Lambert-Beer law, adenine and cytosine extinction coefficients in aqueous solutions were determined and subsequently used to calculate their residual concentrations. At the next stage, the kinetics of nitrogenous bases ozonized oxidation was studied with equal initial concentrations of the starting substances ([NB]0 = [О3]0). The results revealed that the kinetic consumption curves of the starting reagents are fairly well linearized (r ≥ 0.996) in the second-order reaction equation coordinates. As found with the bubbling installation, 1 mol of the absorbed ozone falls on 1 mol of the used NB. Thus, the reactions of ozone with adenine and cytosine explicitly proceed according to the second-order kinetic laws (the first – according to О3 and the first – according to NB). The rate constants were calculated by the integral reaction equations, the values of which indicate a higher ozone reactivity in relation to nitrogen bases. The temperature dependences of the second-order rate constants was studied ranging 285-309 K, and the activation parameters (pre-exponential factors and activation energies) of the ozone reactions with adenine and cytosine in aqueous solutions were determined.

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