Effects of surface charge, micro-bubble size and particle size on removal efficiency of electro-flotation

2006 ◽  
Vol 53 (7) ◽  
pp. 127-132 ◽  
Author(s):  
M.Y. Han ◽  
M.K. Kim ◽  
H.J. Ahn
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Removal Efficiency ◽  
Bubble Size ◽  
Metal Ion ◽  
Ion Concentration ◽  
Collision Efficiency ◽  
Flotation Process ◽  
Zeta Potentials ◽  
Micro Bubble

Flotation is a water treatment alternative to sedimentation, and uses small bubbles to remove low-density particles from potable water and wastewater. The effect of zeta potential, bubble size and particle size on removal efficiency of the electro-flotation process was investigated because previous model-simulations indicated that these attributes are critical for high collision efficiency between micro-bubbles and particles. Solutions containing Al3 +  as the metal ion were subjected to various conditions. The zeta potentials of bubbles and particles were similar under identical conditions, and their charges were influenced by metal ion concentration and pH. Maximum removal efficiency was 98 and 12% in the presence and absence of flocculation, respectively. Removal efficiency was higher when particle size was similar to bubble size. These results agree with modelling simulations and indicate that collision efficiency is greater when the zeta potential of one is negative and that of the other is positive and when their sizes are similar.

Collision efficiency factor of bubble and particle (abp) in DAF: theory and experimental verification

2001 ◽  
Vol 43 (8) ◽  
pp. 139-144 ◽  
Author(s):  
M. Han ◽  
W. Kim ◽  
S. Dockko
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Bubble Size ◽  
Efficiency Factor ◽  
Collision Efficiency ◽  
Turbidity Removal ◽  
Dissolved Air Flotation ◽  
Accepted Practice ◽  
Bubble Sizes ◽  
Dissolved Air

The collision efficiency factor of bubble and particle (αbp) in dissolved air flotation (DAF) can be calculated theoretically by trajectory analysis, which takes into account both hydrodynamics and inter-particle forces. To determine the theoretically optimum particle size for any given bubble size, a collision efficiency diagram for DAF was developed where collision efficiency is contoured on a plane of particle and bubble sizes for different conditions of particle zeta potential. A set of experiments tested the validity of the suggested collision efficiency diagram, and examined whether pretreatment is important and why slight coagulant overdosing and shorter flocculation times are generally preferred in DAF, both current accepted practice. Batch DAF reactors were used and kaolin samples were prepared from jar tests using different alum dosages and flocculation times. The particle size distribution, particle zeta potential, and turbidity removal in each experiment were measured, as were bubble size and zeta potential. The results agreed well with the predictions of the collision efficiency diagram and explained current practices. A collision efficiency diagram identifies the pretreatment goal, i.e., tailoring of the optimum characteristics required of particles (zeta potential and size) under existing operational bubble characteristic.

scholarly journals Ricinus CommunisPericarp Activated Carbon Used as an Adsorbent for the Removal of Ni(II) From Aqueous Solution

2008 ◽  
Vol 5 (4) ◽  
pp. 761-769 ◽  
Author(s):  
S. Madhavakrishnan ◽  
K. Manickavasagam ◽  
K. Rasappan ◽  
P. S. Syed Shabudeen ◽  
R. Venkatesh ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Activated Carbon ◽  
Contact Time ◽  
Metal Ion ◽  
Ricinus Communis ◽  
Ion Concentration ◽  
Batch Mode ◽  
Adsorption Data ◽  
Initial Ph

Activated carbon prepared from Ricinus communis Pericarp was used to remove Ni(II) from aqueous solution by adsorption. Batch mode adsorption experiments are carried out by varying contact time, metal-ion concentration, carbon concentration and pH to assess kinetic and equilibrium parameters. The adsorption data were modeled by using both Langmuir and Freundlich classical adsorption isotherms. The adsorption capacity (Qo) calculated from the Langmuir isotherm was 31.15 mg/g of activated carbon at initial pH of 5.0±0.2 for the particle size 125-250 µm.

Removal of clay and blue-green algae particles through zeta potential and particle size distribution in the dissolved air flotation process

2006 ◽  
Vol 6 (1) ◽  
pp. 95-103 ◽  
Author(s):  
D.H. Kwak ◽  
S.J. Kim ◽  
H.J. Jung ◽  
C.H. Won ◽  
S.B. Kwon ◽  
...  
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Green Algae ◽  
Dissolved Air Flotation ◽  
Flotation Process ◽  
Clay Particles ◽  
Blue Green Algae ◽  
Dissolved Air

The raw water characteristics of a water treatment plant in Korea are mainly dependent on two major factors: the clay particles attributed to rainfall and blue-green algae in reservoirs. In this work, zeta potential and particle size distributions of clay and algae particles, which are the important parameters affecting their removal efficiency, were measured to investigate the behavior and removal characteristics of particles under various conditions. The results showed that the zeta potential of blue-green algae was more sensitive to treatment conditions than clay, and it fluctuated highly with coagulant dosage, suggesting that the control of zeta potential is important for effective removal of algae particles. On the other hand, the range of particle size distribution that remained from the preliminary sedimentation tank was generally smaller than for flotation. However, the zeta potential of the remaining particles was either close to the isoelectric point or positive, and the particles were not so hard to remove for that reason. In the final analysis, for simultaneous removal of clay and algae particles, a sufficient zeta potential difference must be formed not only for algae particles but also for small clay particles from the sedimentation tank in the dissolved air flotation process.

scholarly journals PHYSICOCHEMICAL CHARACTERIZATION OF PROPRANOLOL-LOADED CHITOSAN NANOPARTICLES FOR A BUCCAL DRUG DELIVERY SYSTEM

2020 ◽  
pp. 243-247
Author(s):  
SIRIPORN KITTIWISUT ◽  
PAKORN KRAISIT
Keyword(s):  
Drug Delivery ◽  
Particle Size ◽  
Zeta Potential ◽  
Drug Delivery System ◽  
Delivery System ◽  
Chitosan Nanoparticles ◽  
Particle Sizes ◽  
Zeta Potentials ◽  
Ph Values ◽  
Buccal Drug Delivery

Objective: This study aimed to characterize the physicochemical properties, including pH, zeta potential, and particle size of propranolol-loaded nanoparticles that were incorporated into a buccal transmucosal drug-delivery system. Methods: An ionotropic gelation technique was used to formulate propranolol-loaded chitosan nanoparticles. Chitosan used as the nanoparticle base, using tripolyphosphate (TPP) as a cross-linking agent. The effects on nanoparticle physical properties, including pH, zeta potential, and particle size were examined when various chitosan [0.150-0.300 % (w/v)] and propranolol contents (0-40 mg) were used during the preparation. The effects of using chitosan solutions with different pH values on nanoparticle properties were also determined. Results: The pH values of all nanoparticles ranged between 4.14–4.55. The zeta potentials of the prepared nanoparticles ranged between 22.6–52.6 mV, with positive charges. The nanoparticle sizes ranged from 107–140 nm, which are within the range of suitable particle sizes for transmucosal preparations. Conclusion: The pH values, zeta potentials, and particle sizes of the nanoparticle formulations were influenced by the concentrations of chitosan and propranolol and by the pH of the initial chitosan solution. The relationships between nanoparticle properties and all factors primarily depended on the ionic charges of the components, especially chitosan. Our study provides beneficial physicochemical knowledge for the further development of chitosan-based nanoparticles containing propranolol for buccal drug delivery systems.

scholarly journals Studies on Removal of Cr (VI) from Aqueous Solutions Using Powder of Mosambi Fruit Peelings (PMFP) As a Low Cost Sorbent

2012 ◽  
Vol 9 (3) ◽  
pp. 1389-1399 ◽  
Author(s):  
R. Hema Krishna ◽  
A. V. V. S. Swamy
Keyword(s):  
Particle Size ◽  
Aqueous Solutions ◽  
Metal Ion ◽  
Low Cost ◽  
Ion Concentration ◽  
Isotherm Models ◽  
Batch Tests ◽  
Freundlich Adsorption Isotherm ◽  
Equilibrium Data ◽  
Agitation Time

The powder of mosambi fruit peelings (PMFP) was used as an adsorbent for the removal of heavy metal like Cr (VI) from aqueous solutions was studied using batch tests. The influence of physico-chemical key parameters such as the initial metal ion concentration, pH, agitation time, adsorbent dosage, and the particle size of adsorbent has been considered in batch tests. Sorbent ability to adsorb Cr (VI) ions was examined and the mechanism involved in the process investigated. The optimum results were determined at an initial metal ion concentration was 10 mg/lit, pH=2, agitation time – 60 min, an adsorbent dose (150 mg/50 ml) and the particle size (0.6 mm). The % adsorption, Langmuir constants [Q0=7.51(mg/g) and b=1.69(mg/lit)] Freundlich constant(Kf=2.94), Lagergren rate constants (Kad(min-1)=5.75 x 10-2) for [Cr(VI)] 10 mg/lit were determined for the adsorption system as a function of sorbate concentration. The equilibrium data obtained were tested using Langmuir, Freundlich adsorption isotherm models, and the kinetic data obtained were fitted to pseudo first order model.

Mercury Sorption on Chitosan

2007 ◽  
Vol 20-21 ◽  
pp. 635-638 ◽  
Author(s):  
Karol Campos ◽  
Eric Guibal ◽  
Francisco Peirano ◽  
M. Ly ◽  
Holger Maldonado
Keyword(s):  
Particle Size ◽  
Metal Ion ◽  
Fixed Bed ◽  
Sorption Isotherms ◽  
Sorption Kinetics ◽  
Breakthrough Curves ◽  
Ion Concentration ◽  
Fixed Bed Reactor ◽  
Continuous Systems ◽  
Maximum Sorption

Mercury sorption on chitosan was investigated in batch and continuous systems. Chitosan sorption properties were determined through sorption isotherms. Langmuir and Freundlich equations were used for the modeling of isotherms at pH 5. In batch systems, maximum sorption capacities reached 550 mg Hg/g. Sorption kinetics have been studied as a function of sorbent particle size and stirring rate. Dynamic removal of mercury was tested in a fixed bed reactor investigating the following parameters: particle size, column size, flow velocity and metal ion concentration. Clark and Adams-Bohart models were evaluated for the simulation of breakthrough curves. This study shows that chitosan is an effective sorbent for the treatment and recovery of mercury from dilute effluents at near neutral pH.

scholarly journals Optimization of multiple parameters for adsorption of arsenic (III) from aqueous solution using Psidium guajava leaf powder

2021 ◽  
Author(s):  
Uma Sankar Behera ◽  
Prakash Chandra Mishra ◽  
G. B. Radhika
Keyword(s):  
Aqueous Solution ◽  
Particle Size ◽  
Metal Ion ◽  
Psidium Guajava ◽  
Ion Concentration ◽  
Adsorption Parameters ◽  
Batch Mode ◽  
Equilibrium Study ◽  
Multiple Parameters ◽  
Desorption Study

Abstract The conventional method of water treatment using activated carbon from several sources has been focused extensively since the last two decades. However, rare attention has been noticed on natural adsorbents such as plant leaves. Therefore, the Psidium guajava (Guava) leaf has been investigated to understand it's adsorption efficacy for Arsenic (III) [As(III)] in this study. The effect of process variables, e.g., pH, concentration of metal ion, adsorbent's particle size, and dosages, are evaluated. Experiments are carried out in batch mode, and the individual and combined parameter's impact on adsorption have been discussed. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) is used to characterize the adsorbent's surface. Freundlich and Langmuir's isotherms are used for adsorption equilibrium study. The adsorption parameters are optimized by establishing a regression correlation using central composite design (CCD) of response surface methodology (RSM). The analysis of variance (ANOVA) suggests a high regression coefficient (R2 = 0.9249) for the removal of As(III). Particle size of 0.39 mm; adsorbent's height of 10 cm; metal ion concentration of 30 ppm, and pH 6 are optimized to remove 90.88% As(III) from aqueous solution. HCl is evaluated as a potential solvent for desorption of arsenic from desorption study.

Effects of Wettability and Zeta Potential of Filter Medium on Oil Removal

2010 ◽  
Vol 148-149 ◽  
pp. 58-70
Author(s):  
Qing Chang ◽  
Bin Wu Yang ◽  
Bi Gui Wei
Keyword(s):  
Zeta Potential ◽  
Removal Efficiency ◽  
Capillary Rise ◽  
Streaming Potential ◽  
Filter Medium ◽  
Oil Removal ◽  
Filter Media ◽  
Zeta Potentials ◽  
Removal Efficiencies

The methods and devices which can be used to determine the wettability and zeta potential of filter medium were developed according to the principles of capillary rise and streaming potential respectively. Lipophilic Hydrophilic Ratio (LHR) was defined based on Washburn equation. LHR values and zeta potentials of some conmen filter media were measured respectively, and the oil removal efficiencies of these filter media were also tested. The result shows that the effect of wettability on oil removal efficiency is much greater than that of zeta potential in conmen condition. The oil removal efficiency mainly depends on LHR value of filter medium, not on zeta potential of filter medium.

scholarly journals Micro-Bubble Flotation for Removing Cadmium Ions from Aqueous Solution: Artificial Neural Network Modeling and Kinetic of Flotation

2019 ◽  
Vol 20 (2) ◽  
pp. 1-9
Author(s):  
Abeer I. Alwared ◽  
Nada Abdulrazzaq ◽  
Baseem Al-Sabbagh
Keyword(s):  
Aqueous Solution ◽  
Removal Efficiency ◽  
Removal Rate ◽  
Neural Network Modeling ◽  
Flotation Process ◽  
Cadmium Ions ◽  
Micro Bubble ◽  
Flotation Technique ◽  
Hidden Layer ◽  
Maximum Removal

In this work, microbubble dispersed air flotation technique was applied for cadmium ions removal from wastewater aqueous solution. Experiments parameters such as pH (3, 4, 5, and 6), initial Cd(II) ions concentration (40, 80, and 120 mg/l)  contact time( 2, 5, 10 , 15, and 20min), and surfactant (10, 20and 40mg/l) were studied in order to optimize the best conditions .The experimental results indicate that microbubbles were quite effective in removing cadmium ions and the anionic surfactant SDS was found to be more efficient than cationic CTAB in flotation process. 92.3% maximum removal efficiency achieved through 15min at pH 5, SDS surfactant concentration 20mg/l, flow rate250 cm3/min and at 40mg/l Cd(II) ions initial concentration. The removal efficiency of cadmium ion was predicted through 11 neurons hidden layer, with a correlation coefficient of 0.9997 between ANN outputs and the experimental data and through sensitivity analysis, pH was found to be most significant parameter (25.13 %).The kinetic flotation order for cadmium ions almost first order and the removal rate constant (k) increases with decreasing the initial metal concentration.

scholarly journals Factory Tea Waste Biosorbent for Cu(II) and Zn(II) Removal from Wastewater

2021 ◽  
Vol 287 ◽  
pp. 04006
Author(s):  
Patrick Tan Peng Jun ◽  
Wan Nur Aisyah Wan Osman ◽  
Shafirah Samsuri ◽  
Juniza Md Saad ◽  
Muhamad Fadli Samsudin ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Removal Efficiency ◽  
Metal Ion ◽  
Metal Removal ◽  
Ph Value ◽  
Heavy Metal Removal ◽  
Fixed Bed ◽  
Ion Concentration ◽  
Fixed Bed Adsorption ◽  
Tea Waste

Recent studies have shown great interest toward heavy metal removal due to its hazardous and non-biodegradable properties. Many approaches have been used for this purpose and one of them is adsorption. In this study, several experiments were carried out to investigate the feasibility of factory tea waste as a biosorbent in a fixed-bed adsorption column for heavy metal removal (zinc and copper) in wastewater. The results highlighted that zinc has better performance compared to copper in terms of the effect of initial ion concentration, pH value, and the mixed ions with respect to the removal efficiency. Zinc showed higher removal efficiency and adsorption capacity at the initial metal ion concentration of 200 mg/L, which are 99.21% and 39.68 mg/mg compared to copper. Meanwhile, for the effect of pH values and mixed ion concentration, zinc also showed slightly higher removal efficiency which are 99.91% and 98.47%, respectively compared to copper. However, both zinc and copper showed a better fit to the Langmuir isotherm. The factory tea waste was characterized using Micromeritics ASAP 2020 instrument and results showed that the factory tea waste biosorbent consists of mesopores with the diameter and width of 4.85205 and 2.546985 nm, respectively.

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