Ion Flotation

Pinfold, T. A.

doi:10.1016/b978-0-12-443350-2.50009-5

Cited by 13 publications

(9 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The formation of scum with La 3+ but not Cd 2+ or Cs + at equal stoichiometries is consistent with observations of decreasing solubility of transition metal cation complexes with anionic surfactants as metal valence increases [43]. Scum formation in lieu of foam during ion flotation is perfectly acceptable [19] and perhaps preferable because it provides highly concentrated material that is easily removed from the surface. The lack of foam formation suggests there were insufficient monomers available to produce a foam.…”

Section: Collector-to-colligend Ratio Effectsupporting

confidence: 84%

“…Preliminary experiments were also performed to determine an ethanol frother concentration of 0.5 or 0.8% (v/v) (see supplementary materials). Finally, ion flotation has been found to be most efficient at or below the collector's CMC [18,19,38]. This is because aggregated surfactants compete with interface-attached surfactants for colligend, hindering flotation.…”

Section: Ion Flotation Experimentsmentioning

confidence: 99%

“…This rapid initial rate of removal is desirable because it reduces the time required to complete the flotation process during batch operations. Due to column design, however, metal removed from solution is not actually removed from the column until the foam Scum formation in lieu of foam during ion flotation is perfectly acceptable [19] and perhaps preferable because it provides highly concentrated material that is easily removed from the surface. The lack of foam formation suggests there were insufficient monomers available to produce a foam.…”

Section: Metal Removal Measured By Foamate Fractionsmentioning

confidence: 99%

“…The solution remaining in the column then has a reduced metal concentration and is ready for additional treatment or release. Since its first description by Sebba [19] in 1959, a large body of research has demonstrated ion flotation's efficacy and optimal operating conditions for a wide variety of collector and colligend pairs (see Pinfold, Matis & Mavros, and Lemlich [15,18,20] for literature reviews). This body demonstrates two important advantages of ion flotation over other treatment approaches: (1) it can achieve high metal removal efficiencies even when metals are very dilute in solution and (2) selective metal recovery is possible by manipulating the collector and other flotation conditions.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Ion Flotation of La3+, Cd2+, and Cs+ using Monorhamnolipid Collector

Hogan

Curry

Maier

2018

Colloids and Interfaces

View full text Add to dashboard Cite

Water scarcity is a global issue that is expected to continue increasing in importance in the coming decades. Reclaimed water is one important source available to meet future needs. The reclamation process for wastewaters, particularly from industrial sources, involves the need to remove low-level contaminants. Here we report the efficacy of an ion flotation process that uses the biosurfactant monorhamnolipid as a metal collector to recover Cs + , Cd 2+ , and La 3+ from water. These elements were tested at collector-to-colligend ratios of 2, 5, and 10. The collector-to-colligend ratio and metal valence play a large role in determining flotation success with removal efficiencies varying widely. The maximum removal efficiency for the metals when floated individually were 46.2, 99.8, and 98.6% for Cs + , Cd 2+ , and La 3+ , respectively. When mixed together at near equimolar concentrations removal efficiencies were 39.4, 98.4, and 88.1%, respectively. Removal efficiency for Cs + , Cd 2+ , and La 3+ were up to 49.9, 99.5, and 51.5% when mixed at a ratio of 200:10:1, whereas conditional stability constants predict a removal order of La 3+ > Cd 2+ > Cs + . Future research should examine parameters, including pH and ionic strength, that may affect the flotation process as well as actual metal-contaminated waste streams to evaluate the usefulness of this technology.Colloids Interfaces 2018, 2, 43 2 of 15 in wastewater treatment for their ability to remove and concentrate dissolved metal ions from solution: precipitate and ion flotation [10]. The former utilizes chemicals to precipitate dissolved metals and air bubbles to collect the resulting precipitate at the solution surface [10]. The latter concentrates dissolved, surface-inactive ions (colligends) through complexation with surfactants (collectors) and subsequent introduction of air bubbles. The ion-surfactant complexes (sublate) attach to the bubble air/water interfaces and accumulate at the solution surface as foam that can then be collected into a metal concentrate herein called foamate [18]. The solution remaining in the column then has a reduced metal concentration and is ready for additional treatment or release. Since its first description by Sebba [19] in 1959, a large body of research has demonstrated ion flotation's efficacy and optimal operating conditions for a wide variety of collector and colligend pairs (see Pinfold, Matis & Mavros, and Lemlich [15,18,20] for literature reviews). This body demonstrates two important advantages of ion flotation over other treatment approaches: (1) it can achieve high metal removal efficiencies even when metals are very dilute in solution and (2) selective metal recovery is possible by manipulating the collector and other flotation conditions. When developing a flotation process, the collector characteristics of collector-colligend selectivity, critical micelle concentration, solubility, toxicity, and biodegradability should be considered. The latter two points are particularly important because some collector will rema...

show abstract

Section: Collector-to-colligend Ratio Effectsupporting

confidence: 84%

Section: Ion Flotation Experimentsmentioning

confidence: 99%

Section: Metal Removal Measured By Foamate Fractionsmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Ion Flotation of La3+, Cd2+, and Cs+ using Monorhamnolipid Collector

Hogan

Curry

Maier

2018

Colloids and Interfaces

View full text Add to dashboard Cite

show abstract

“…In ion-flotation the kinetics of a solute removal from water can be approximated mostly by a direct or reversible first or second order chemical reaction [3,8,9]. In the rate equation derived here, it is assumed that all amount of unvolatile sublates removed from the aqueous phase (Vaq) with the carrier gas flow-rate (Vga~) is entirely dissolved and remains in the organic phase (Vorg).…”

Section: Theoreticalmentioning

confidence: 99%

Kinetics of transport extraction based on solvent sublation

Palágyi

1999

Czech J Phys

View full text Add to dashboard Cite

The kinetics of this transport extraction has been studied in a 13112 -N-cetylpyridinium chloride complex pair model system under static conditions with a stagnant aqueous phase and a stationary organic solvent. Using N2 carrier gas at a flow rate of 60 cm3/min, separation efficiencies up to 95% were obtained within 2 hr. with a 400-fold preconcentration of radioiodine into 10 cm 3 of benzene from 4 dm 3 model samples of deionized, tap and river waters. Relevant equations have been derived, from which the separation efficiency, the mass-transfer rate constant and the separation half-time can be calculated in dependence on time for various experimental conditions. The mass distribution constant of solute between the surface of the carrier gas bubbles and aqueous phase of the process can also be evaluated. Introduction Sublation as a separation technique based on the adsorptive bubble (adsubble)processes, is a collection process opposite to precipitation, in which surface-active solutes, or solutes made surface active with a suitable surfactant, are separated from water. Solvent sublation is an option to ion-flotation, where the sublate formed between solute (colligend) and an oppositely charged surface active agent (collector) is adsorbed on the bubble surfaces of an ascending gas stream and collected into an immiscible organic solvent layer placed on top of the water column [1][2][3][4][5]. This technique can be recognized as an alternative to normal, equilibrium solvent extraction and viewed as a non-equilibrium transport extraction. In transport extraction, the transfer of the hydrophobized solutes from a stagnant bulk aqueous phase into the stationary organic phase takes place only at the relatively small interface of the phases, where true equilibrium distribution of the solute between phases is only established [4,5]. Therefore, in the separation of solutes from relatively large volumes of water (i.e., with high preconcentration factor), the kinetics of the transport extraction may play a considerable role in the separation performance, e.g., in comparison with conventional solvent extraction, where the separation of solute takes place in the bulk aqueous phase through immeasurable large contact surface area of the phases during their intensive mixing.The aim of this paper was to investigate the kinetics of the transport extraction under static conditions from a stagnant aqueous phase into a stationary organic phase (benzene), using a 13112-N-cetylpyridinium chloride (CPC) cationic surfactant complex pair model system [6,7]. Both liquid-liquid transport extraction and polyurethane foam (PU) supported transport extraction were applied. Relevant kinetic equations have been derived, from which the separation efficiency, the mass-transfer rate constant and the separation half-time of the process can be calculated in dependence

show abstract