José Manuel Benito

• PhD
• University of Burgos

In this study, we aimed to prepare stable water-in-oil (W/O) nanoemulsions loaded with a phenolic-rich aqueous phase from olive cake extract by applying the response surface methodology and using two methods: rotor-stator mixing and ultrasonic homogenization. The optimal nanoemulsion formulation was 7.4% (w/w) of olive cake extract as the dispersed...

Olive pomace, a solid residue generated during olive oil production process and a rich source of phenolic compounds, was dried and defatted to obtain a pomace oil rich in monounsaturated fatty acids with 64% oleic acid. The defatted pomace was further treated by ultrasound-assisted extraction (UAE). The optimal phenol extraction conditions of 10 mi...

Currently, industry is requesting proven techniques that allow the use of encapsulated polyphenols, rather than free molecules, to improve their stability and bioavailability. Response surface methodology (RSM) was applied in this work to determine the optimal composition and operating conditions for preparation of water-in-oil-in-water (W/O/W) emu...

This work reports the study of surface and aggregation properties of formulations containing mixed niosomes of the non-ionic surfactant sorbitan monooleate (Span 80) and the cationic surfactant cetyltrimethylammonium bromide (CTAB), in concentrations of 20 and 4 mol/m³, respectively, in salt-free water and in the presence of NaCl (20, 50 and 80 mol...

In the present work the effect of High Pressure Carbon Dioxide (HPCD) on the activity and structure of a commercial pectin methylesterase (PME) was studied and the results were compared to the conventional thermal inactivation technology. The use of supercritical CO2 (pressure 6–18 MPa, temperature 40–55 °C and time up to 75 min) increased dramatic...

A new isolated Bacillus mojavensis strain I4 was found as producer of biosurfactants by different screening methods such as parafilm M test, hemolytic activity, oil displacement test, emulsification index, surface tension and lipase production assay. Enhanced biosurfactants production was obtained using glucose and glutamic acid as carbon and nitro...

The ultrafiltration process for separation of sodium lactate from sorbitan monooleate (Span 80) and sodium dodecyl sulfate (SDS) surfactants using ZrO2 flat-disc ultrafiltration membranes was studied in this work. The study is focused on the influence of the nominal molecular weight limit of the membrane (NMWL), the transmembrane pressure (TMP), an...

A nanofiltration (NF) process applied to both single solutes (charged and uncharged) and electrolyte mixtures formed by a dominant salt and trace ions was evaluated in this work. Experiments were performed in a pilot plant using a 200 Da cut-off spiral-wound polymeric membrane. The marked differences in rejection of the same trace ion in the presen...

Ultrafiltration (UF) of oil-in-water (O/W) emulsions formulated with 1 wt% base oil (an 85/15% (w/w) mixture of a synthetic poly-α-olefin and trimethylol propane trioleate ester, respectively), and a surfactant (anionic, Oleth-10, nonionic, Brij 76, or cationic, CTAB) at several concentrations referred to its critical micelle concentration (CMC) wa...

The solubilization process of sorbitan monooleate (Span 80) niosomes, formed by sonication, by addition of the anionic surfactant sodium dodecyl sulfate (SDS) was studied in this work. The main parameters studied were the optical density at 350 nm wavelength, particle size distribution, zeta potential, and the concentration of SDS monomers in the d...

This study examines the effects of different formulation parameters on the physico-chemical properties of niosomes containing Span 80 (sorbitan monooleate), cholesterol and/or SDS (sodium dodecyl sulfate), and lactic acid for the future use of formulated niosomes as lactic acid extraction agents in aqueous solutions. Niosomes were prepared by direc...

A hybrid process has been studied for an oil-in-water (O/W) emulsion treatment. This process consisted of two stages: emulsion destabilization by coagulation/centrifugation with calcium chloride, and subsequent ultrafiltration (UF) using a 300kDa tubular multichannel ZrO2 ceramic membrane. The O/W emulsion was formulated from a commercial oil conce...

Abstract Lactic acid recovery from dilute aqueous solutions by microfiltration using niosomes of Span 80 (sorbitan monooleate) modified by SDS (sodium dodecyl sulfate) as extraction agents was studied. Experiments were conducted at a transmembrane pressure of 0.3 bar using a 0.20 μm pore size TiO2 microfiltration flat-disk membrane. The effect of t...

The feasibility of an activated charcoal/ultrafiltration process for the decolouration of beet molasses, and subsequent regeneration of the exhausted charcoal by thermal and chemical methods, has been examined. Several activated charcoals were assayed prior to the selection of Norit powdered activated charcoal (NPAC). The affinity of NPAC for the a...

Wheat bran oil (WBO) has been reported to have an important content of bioactive compounds, such as tocopherols, alkylresorcinols, steryl ferulates and other phenolic compounds; however, its poor solubility in water systems restricts its applications in the food industry. This study is focussed on the formulation of oil-in-water (O/W) nanoemulsions...

A coagulation–centrifugation/ultrafiltration hybrid process has been performed for the treatment of a commercial oil-in-water emulsion used in metalworking operations. The effect of pre-treatment stage on membrane fouling was evaluated to ascertain the main fouling mechanism and to establish the best membrane cleaning procedure. The hybrid process...

The effects of different formulations on the physicochemical properties of unloaded and carboxylic acid-loaded niosomes are studied. Citric acid and lactic acid were the model carboxylic acids employed. The niosomes were prepared by ultrasonication of different formulations in a phosphate buffer at pH 2 and 7 containing Tween 80 (polyoxyethylene (2...

A two-step technique for preparing highly concentrated oil-in-water (O/W) emulsions, also called high internal phase emulsions (HIPEs) is proposed. Four different oils were selected as the internal phase: castor oil, heavy mineral oil, soybean oil and light mineral oil, and a non-ionic surfactant Tween 20 (polyoxyethylenesorbitan monolaurate) was c...

Vacuum evaporation of aqueous surfactant systems and concentrated oil-in-water (O/W) and water-in-oil (W/O) emulsions was studied as a function of the base oil (castor oil, heavy mineral oil and light mineral oil), and the kind of non-ionic surfactant (Tween and Span series) used in their formulation. Water evaporation rates were measured from aque...

Oily wastewaters are usually treated by physical, chemical and biological methods. Most conventional methods (coagulation, sedimentation, centrifugation and filtration) are not efficient in treating stable oil-in-water (O/W) emulsions, especially when the oil droplets are finely dispersed and the concentration is very low. These techniques can redu...

Metalworking processes utilize large amounts of oils or oil-in-water (O/W) emulsions for lubrication and cooling in operations such as cutting, grinding, drawing or rolling. These emulsions lose their functional properties with use by thermal degradation and chemical contamination, and they must be replaced. Large volumes of oily wastewater are gen...

Three metalworking fluids (MWFs) from a copper wire drawing industry were monitored for a two-year period by studying changes in their functional properties: two semi-synthetic oil-in-water (O/W) emulsions used in smoothing and wire drawing processes and one synthetic fluid used in the casting process. The parameters measured were: zeta potential,...

The effect of flocculants on the ultrafiltration (UF) of activated sludge from a wastewater treatment plant, using organic membranes, was investigated. Flocculation trials were performed with commercial flocculants, ZETAG 7197 (an aliphatic polyamine) and Nalco MPE30 and MPE50 (cationic polymers). Optimal dosage was determined as a function of the...

A process is proposed for the treatment of a waste oil-in-water (O/W) emulsion generated in an industrial copper-rolling operation. The use of demulsifier agents improves the subsequent treatment by techniques such as ultrafiltration (UF) or evaporation. The effluent COD is reduced up to 50% when the O/W emulsion is treated by UF using a flat 30 nm...

Vacuum evaporation of surfactant solutions and oil-in-water (O/W) emulsions at laboratory-scale set-up was investigated. Experiments were performed with surfactant solutions and model emulsions formulated with a base oil (85–15% (w/w) mixture of a synthetic poly-α-olefin and a trimethylol propane trioleate ester, respectively) and the following sur...

The aim of this work was to determine the optimal surfactant concentration and operating conditions for betaine recovery from aqueous solutions by micellar-enhanced ultrafiltration (MEUF). Initial centrifugal ultrafiltration experiments with commercial 5 kDa cutoff polyethersulfone membranes showed that optimal betaine extraction was achieved with...

The performance of colloidal dispersion systems such as emulsions and suspensions depends greatly on their formulation. A proper characterization of the system oil–water–surfactant for emulsions used in metalworking operations may extend emulsion life and lower process costs. The behavior of an oil-in-water (O/W) emulsion formulated in our laborato...

The performance of vacuum evaporation was evaluated for the treatment of waste oil-in-water (O/W) emulsions, one synthetic (Multiroll) and two semisynthetic (Unopol and Divinol), used in a copper metalworking industry. A destabilization/settling pretreatment step using Nalco 71243 (NAL, a quaternary polyamine) as flocculant and CaCl2 and AlCl3·6H2O...

Mass transport and hydrodynamics have to be considered in order to analyze and optimize the performance of membrane systems. Some basic mass transfer models and hydrodynamic effects, that provide qualitative information to simplify the task of membrane design and operation are discussed for pressure-driven membrane separations.

The feasibility of using ultrafiltration permeates to reformulate oil-in-water (O/W) emulsions was evaluated. In order to optimize the ultrafiltration process the effect of the operating conditions (crossflow velocity, transmembrane pressure and temperature) on permeate flux and chemical oxygen demand (COD) using two tubular ceramic membranes of 20...

The effect of a commercial flocculant (Alpacon (R) WS009) and two coagulant salts (CaCl(2) and AlCl(3)) on the stability of metalworking oil-in-water (O/W) emulsions was examined. Two O/W emulsions were tested: a fresh emulsion, prepared in the laboratory from a commercial concentrate, and a waste metalworking emulsion, provided by a local waste ma...

Droplet size is a key factor in the treatment of oil‐in‐water (O/W) emulsions, because of its influence on emulsion properties. The addition of a coagulant salt generally causes emulsion destabilization, increasing the droplet size, and enhancing coalescence between oil droplets, which helps its further treatment. The influence of CaCl2 addition on...

The creaming stability and wetting behaviour of oil-in-water (O/W) emulsions, designed to be used as metalworking fluids, were evaluated. The influence of the emulsifier type and its concentration on emulsion properties (droplet size distribution, zeta potential, creaming stability, and contact angle or work of adhesion) was studied. O/W emulsions...

A simple batch vacuum evaporation process for the treatment of several oil-in-water (O/W) emulsions is reported. The experiments were carried out with waste emulsions from an industrial copper rolling process and with model emulsions prepared in the laboratory. No detailed information on the formulation of the industrial waste O/W emulsions was ava...

Extreme pressure tests following the ASTM D 2783 standard were carried out to evaluate the performance of several oil-in-water (O/W) emulsions used as lubricating and cooling fluids in machining operations. The effect of concentration of three different emulsifiers (anionic, non-ionic, and cationic surfactants) on the extreme pressure properties of...

A method for the determination of the drop size distribution of oil-in-water (O/W) emulsions is presented. Water-based coolant emulsions used in rolling mill operations were studied. The emulsions were gelled in agarose so that the oil droplets were immobilized and samples of these gels were measured by confocal laser scanning microscopy (CLSM) and...

The recovery of α-phenylglycine from diluted aqueous solutions by micellar extractive ultrafiltration (MEUF) was investigated using several surfactants as extraction agents: cetyl trimethyl ammonium bromide (CTAB, cationic), sodium dodecyl benzene sulfonate (SDBS, anionic), polyoxyethylene-sorbitan mono-oleate (Tween 80, non-ionic) and lauryl sulfo...

The effect of pH and crossflow velocity on the ultrafiltration of a model metalworking o/w emulsion was studied. The emulsion was prepared using a vegetable oil as the base oil and a mixture of anionic and non-ionic surfactants as emulsifiers. Experiments were carried out using Carbosep® tubular ceramic membranes with two different cut offs (50 and...

The effect of operating conditions on the performance of a sawdust bed filter used for the treatment of an oil-in-water emulsion was investigated. A metalworking fluid (3 vol.% oil) was used as oil-in-water emulsion and sawdust as filter medium and sorbent. Because of the high stability of the emulsion, small amounts of inorganic salt (calcium sulp...

Although the use of oil-in-water (O/W) emulsions as metalworking fluids is widespread, the mechanisms of emulsion lubrication are not yet well understood. Several theories have been proposed but there is not a clear agreement about the effect of different operating conditions and emulsion properties on the lubricating performance of O/W emulsions....

Oil-in-water (O/W) emulsions used in machining processes were treated in a laboratory bottle centrifuge and in a pilot-scale disc-stack centrifuge. Small amounts of a coagulant salt (CaCl2, in the concentration range 0.01–0.5 M) were added to promote emulsion destabilization and to improve centrifugation. Grade efficiency curves were obtained from...

The effect of two coagulant salts, CaCl2 and AlCl 3·6H2O, on the stability of a metalworking oil-in-water (O/W) emulsion was examined. Emulsion stability and stabilization mechanism were studied as a function of pH and coagulant salt concentration through zeta potential and multiple light scattering measurements. Both coagulant salts were effective...

The stability of two oil-in-water emulsions (smoothing emulsion and finishing emulsion) used as lubricants and coolants in an industrial copper rolling process was studied as a function of time. Four parameters were measured: droplet size distribution, zeta potential, surface tension and contact angle. Experimental results show that zeta potential...

Extractive ultrafiltration of α-phenylglycine from sodium hydroxide solutions with the ion-exchange extractant trialkylmethylammonium chloride (TOMACl) dissolved in toluene using a microporous polypropylene hollow fiber contactor has been studied. The effect of the hydrodynamic conditions on the mass-transfer rates was determined. The overall mass-...

The ultrafiltration of two types of surfactants, sodium dodecyl sulfate (SDS, anionic) and Tergitol NP-9 (nonylphenol polyethylene glycol ether, nonionic), using a 20nm ZrO2 tubular membrane was investigated. The influence of crossflow velocity, temperature, pressure, and surfactant concentration on the permeate flux, close to and above the critica...

A brief description of some methods used for droplet size analysis is presented. Special attention has been paid to the determination of droplet size distribution (DSD) of oil-in-water emulsions, used as water-based coolants, and destabilized by addition of CaCl2. The emulsions were gelled in agarose so that the oil droplets were immobilized and sa...

The design, optimization and integration of pressure-driven membrane process require a vast array of information. Such information is usually given in specification sheets. In the following article Susana Luque, José Manuel Benito and José Coca of the University of Oviedo, Spain, discuss in detail the development of a preliminary pressure-driven me...

The influence of operating conditions on permeate flux was investigated using organic ultrafiltration membranes to treat a synthetic cutting-oil emulsion containing 0.05 to 0.8 wt. % oil. A commercial cutting oil, Alba-Kool, and four organic ultrafiltration membranes, two made of polysulfone (PM10 and PM30) and the other two of regenerated cellulos...

Emulsified oils contained in aqueous effluents from cold-rolling mills of the steel industry can be effectively removed via an integrated process consisting of a coagulation/flocculation stage followed by ultrafiltration of the resulting aqueous phase. The effects of CaCl2, NaOH, and lime on the stability of different industrial effluents were stud...

Oil-in-water (O/W) emulsions act as lubricants and coolants in metalworking operations, in order to reduce friction between the metal piece and mechanical equipment, and to avoid corrosion. Three O/W emulsions from a copper metalworking industry were monitored along time to study changes in their functional properties: two semi-synthetic emulsions...