Abdellah Saboni

Sulfur dioxide absorption and desorption by water drops

A new model is developed for the absorption and desorption of sulfur dioxide by drops falling through air containing a low concentration of it. The model predictions are compared with published experimental results. We observe that whatever the type of absorption or desorption experiments is, the present model fits the experimental results.

Interdrop coalescence with mass transfer: comparison of the approximate drainage models with numerical results

Abstract The partially mobile, plane-film model developed to describe film drainage and rupture during coalescence in liquid–liquid dispersions is extended to take account of interfacial-tension gradients generated by mass transfer. The resulting Marangoni forces are predicted to greatly accelerate film drainage (which in general corresponds to dispersed to continuous phase transfer) and to diminish film drainage in the negative case. The first model is based on the approximation of constant pressure and interfacial tensions outside the film. The predictions from this model agrees with observations and available numerical data, in the case of mass transfer from dispersed to continuous phase. While for mass transfer from continuous to dispersed phase, a second model is proposed, in this case the first model is adapted to take account of the location of the region of maximum concentration gradients, which moves radially outwards as a result of the growth of the continuous phase-concentration boundary layers. At large times, the new model predicts an asymptotic return to the drainage rate in the absence of mass transfer.

Recovery of zinc from chloride media by batch pertraction in a rotating film contactor

A liquid membrane (pertraction) process of zinc recovery from acidic chloride solutions was studied applying a pertraction in a rotating film contactor (RFC). Tri-n-octylamine (TOA or R3N) dissolved in n-octane was used as a carrier. The influence of the main process parameters, such as disc rotation velocity, hydrochloric acid concentration in the aqueous phases and carrier concentration in the membrane was investigated. Assuming the existence of two thin reaction layers in the feed and stripping solutions, adjacent to both water–oil interfaces, a mathematical model was developed to describe the zinc transport. On the basis of the experimental data obtained under various conditions and the model proposed, it was found that the extraction step is controlled mainly by the mass transfer resistance, whereas the stripping rate of zinc is controlled predominantly by the rate of zinc–carrier complex decomposition in the stripping side reaction layer.

Separation of Cobalt and Nickel by Pertraction in a Rotating Film Contactor Using Cyanex 302 as a Carrier

Abstract The extraction behavior of Cyanex 272, Cyanex 301, and Cyanex 302 for recovery of cobalt and nickel from sulphate media was studied. Cyanex 302 was found to be the most suitable reagent for extraction of both metals and for Co(II)/Ni(II) separation. Competitive pertraction of Co(II) and Ni(II) in a rotating film contactor with Cyanex 302 as a carrier was studied. At appropriately chosen operational conditions Co(II) was preferentially removed, while Ni(II) remained in the feed solution. Pertraction process using Cyanex 302 as a carrier guarantees an excellent separation of Co(II) from Ni(II): the obtained separation factors are Ksep∼1.0×104. Higher pH of the feed solution favors the recovery of both metals, but deteriorates Co(II)/Ni(II) separation ability. At neutral pH of the feed solution and strongly acidic acceptor solution, pertraction process can be used for simultaneous and complete recovery of both metals, also.

Pertraction continue de tylosine dans un contacteur a films tournants

Abstract Pertraction or extraction by liquid membranes is a new, prospective separation method for recovery and concentration of antibiotics from their dilute aqueous solutions. Mixture separation by pertraction is a combination of two, widely used and consecutively applied operations: extraction of solute from the feed solution and stripping of the enriched organic phase by another solution. In pertraction processes solute extraction from the feed and its stripping from the extract are combined in a way to provide a maximum yield with minimum extractant losses and energy consumption. The purpose of the present work was the study of continuous tylosin removal from its aqueous solutions in a multistage rotating disc pertractor, applying a counter-current flow. n -Decanol and n -octanol were used as membrane liquids. The effect of the feed solution residence time on pertraction efficiency was studied. A mathematical model describing the process was used for the evaluation of the stage efficiency.

Récupération de substances par pertraction à films tournants

Abstract A rotating film pertraction of phenol from its dilute aqueous solutions and copper from ammoniacal dilute leach solutions are presented. Mathematical models are developed to describe the batch pertraction processes. Using experimental results and models, the partial mass transfer coefficients and the kinetic constants were evaluated.

Selective recovery of silver from dilute polymetal solutions by rotating film pertraction

Recovery of silver from polymetal nitrate solution by means of rotating film pertraction technique was studied. Silver was successfully separated from the accompanying metals, viz. copper, zinc and nickel, using as a membrane phase a 0.06-M solution of tri-isobutylphosphine sulfide (TIBPS) in n-octane and an aqueous ammonia solution as a stripping phase. After 4 h of continuous contacting silver was practically completely extracted from the feed and transferred into the strip solution, while the other three metals remained unextracted.

Silver Recovery from Dilute Aqueous Solutions Using Semi-Batch RF-Pertraction

Silver recovery from dilute nitrate solution was studied by using a rotating film (RF)-pertraction technique in a semi-continuous mode. Triisobutylphosphine sulphide (TIBPS) dissolved in kerosene was used as a carrier and an aqueous ammonia solution as a stripping phase. A high transfer flux of silver ions during the pertraction process was observed. It was shown that the selectivity of silver transport through the TIBPS-containing liquid membrane provides an excellent separation of silver from other metals such as copper, nickel, and iron presented in the treated solutions.