Arturo Romero

Complutense University of Madrid | UCM · Facultad de Ciencias Químicas

Surfactant-enhanced aquifer remediation is commonly applied in polluted sites with dense non-aqueous phase liquids (DNAPLs). This technique transfers the contamination from subsoil to an extracted emulsion, which requires further treatment. This work investigated the treatment of a complex emulsion composed of a nonionic surfactant and real DNAPL f...

A numerical application has been carried out to determine the thermophysical properties of more than fifty pure liquid compounds involved in the production process of cyclohexanone, whose real values are unknown, in many cases. Two group-contribution methods, the Joback and the Marrero–Gani methods, both used in the fields of physicochemistry and e...

The desorption of hydrophobic organic compounds (HOCs) and limited mass transfer in soil systems is a significant challenge for efficient soil remediation by oxidation treatments. The utilization of sonochemistry is a promising technology to enhance the decontamination of HOCs-polluted soils. In this work, ultrasound (US) was coupled to NaOH for ac...

Naphthalene (NAP) has received particular attention due to its impact on the environment and human health, mandating its removal from water systems. In this work, the abatement of NAP in the aqueous phase was achieved using persulfate (PS) activated by Fe (III) and monochromatic LED light at a natural pH. The reaction was carried out in a slurry ba...

Surfactant enhanced aquifer remediation is a common treatment to remediate polluted sites with the inconvenience that the effluent generated must be treated. In this work, a complex mixture of chlorobenzene and dichlorobenzenes in a non-ionic surfactant emulsion has been carried out by volatilization. Since this techhnique is strongly affected by t...

In an attempt to evaluate the separation of certain impurities that arise in some stages of the production of cyclohexanone, this work analyzed the possibility of removing five of these substances via rectification. Due to the scarcity of experimental vapor–liquid equilibrium data for most of the solutions in the effluent of the global process, pri...

Sites polluted by dense non-aqueous phases (DNAPLs) constitute an environmental concern. In situ chemical oxidation (ISCO) application is limited since oxidation often occurs in the aqueous phase and contaminants are usually hydrophobic. In this work, ISCO enhanced by the surfactant addition (S–ISCO) was studied for a complex liquid mixture of chlo...

The inadequate management of wastes associated with chlorinated organic compounds (COCs) has become a huge environmental problem. Surfactant Enhanced In-Situ Chemical Oxidation (S-ISCO) was studied as a successful technique to remediate polluted sites. This work investigated the reaction between an aqueous solution of nonionic surfactant (Emulse-3®...

Persistent organic contaminants affecting soil and groundwater pose a significant threat to ecosystems and human health. Fenton oxidation is an efficient treatment for removing these pollutants in the aqueous phase at acidic pH. However, the in-situ application of this technology for soil remediation (where pHs around neutrality are required) prese...

The equilibrium between surfactant adsorption and contaminants desorption was studied. Two soil samples from a polluted site with residues from lindane production, compounded of a complex mixture of 28 chlorinated organic compounds (COCs) and different concentration of COCs in soil (2.27 and 34.69 mmolCOCs·kgsoil−1), were used. Soil was in contact...

Soils contaminated with hexachlorocyclohexanes (HCHs) are a legacy of the heavy use of lindane during the 20th century. This pesticide production generated large amounts of residues of other HCH isomers, which were habitually mismanaged. The sediments treated in this work (coming from an old lindane landfill) are an example of this environmental pr...

Contamination of organic pollutants such as hexachlorocyclohexane (HCH) isomers poses a significant threat to human health and the environment. The alkaline activation of persulfate (PS) intensified by temperature to remediate surface sediments contaminated with HCH-wastes dumped by a lindane producing company (mainly α-HCH=254 mg kg⁻¹ and β-HCH= 9...

The intensive use of organochlorine pesticides, such as lindane (γ-HCH), and the inadequate management of their wastes, is a huge environmental problem. The lindane production during the last century has generated huge volumes of solid wastes of other HCH isomers, causing hot points of soil and groundwater contamination. The soil treated in this wo...

Surfactant Enhanced In-Situ Chemical Oxidation (S-ISCO) is an emerging technology in the remediation of sites with residual Dense Non-Aqueous Phase Liquids (DNAPLs), a ubiquitous problem in the environment and a challenge to solve. In this work, three nonionic surfactants: E-Mulse3® (E3), Tween80 (T80), and a mixture of Tween80-Span80 (TS80), and a...

Application of surfactants in the remediation of polluted sites with dense nonaqueous phase liquid (DNAPL) still requires knowledge of partitioning between surfactants and pollutants in the organic and aqueous phases and the time necessary to reach this balance. Two real DNAPLs, generated as wastes in the lindane production and taken from the pollu...

Chlorinated pesticides were extensively produced in the XX century, generating high amounts of toxic wastes often dumped in the surroundings of the production sites, resulting in hot points of soil and groundwater pollution worldwide. This is the case of Bailín landfill, located in Sabiñánigo (Spain), where groundwater is highly polluted with chlor...

In this work, remediation of a soil highly polluted with chlorinated organic compounds (COCs), including chlorobenzenes, hexachlorocyclohexane (HCH) and heptachlorocyclohexane (HeptaCH), has been carried out using persulfate (PS) activated by alkali (NaOH). The contamination was caused by wastes from lindane production. Soil samples were sieved in...

Treatment of polluted wastewaters from industrial activities has become a source of major concern for the environment. In this work, real wastewater from a physico-chemical (WWFQ) treatment was tested through different oxidation technologies: Fenton and Fenton-like reagent and persulfate activated by NaOH and Fe(II). Oxidation reactions with Fenton...

The alkaline activation of persulfate (PS) has been tested in this study as in situ oxidation technology for the abatement of dichloromethane (DCM), a chlorinated volatile organic pollutant commonly found in groundwater due to its wide use as solvent in the chemical industry during the last decades. The addition of an alkali (NaOH) as persulfate ac...

Nylon 6 fibres are produced by polymerisation of caprolactam obtained after oximation and Beckmann rearrangement of cyclohexanone. For this reason, the purity of cyclohexanone used is an important parameter to control the quality of final nylon 6 products. The poor quality of cyclohexanone is related to the presence of some cyclic ketone impurities...

Hexachlorocyclohexane (HCH) and mainly the γ-HCH isomer, namely lindane, were extensively produced and used as pesticides. Huge amounts of wastes, solids and liquids, were disposed of in the surroundings of the production sites. The liquid residuum was a complex mixture of chlorinated organic compounds, COCs, from chlorobenzene to heptachlorocycloh...

In this work, the abatement of several chlorobenzenes commonly found as pollutants in the aqueous phase has been carried out by catalytic wet peroxide oxidation using goethite as the catalyst and hydroxylamine as the promotor. Spiked water with monochlorobenzene and different positional isomers of dichlorobenzene, trichlorobenzene, and tetrachlorob...

The etherification of glycerol with tert-butyl alcohol in the presence of acid catalysts gives rise to the production of ethers (monoethers, diethers and triethers) of high added-value, which can be used as oxygenated additives in fuels. This reaction is limited by the thermodynamic equilibrium, which can be modified by the addition of solvents tha...

Carbon tetrachloride (CT), a chlorinated organic compound widely used in the chemical industry during the 20th century, is nowadays a ubiquitous contaminant in groundwater and in situ technologies for its destruction are required. In this work, the degradation of CT by the alkaline activation of persulfate (PS) has been studied. Among the pool of r...

This study is focused on the effective removal of recalcitrant pollutants hexaclorocyclohexanes (HCHs, isomers α, β, γ, and δ) and chlorobenzenes (CBs) present in a real groundwater coming from a landfill of an old lindane factory. Groundwater is characterized by a total organic carbon (TOC) content of 9 mg L⁻¹, pH0 = 7, conductivity = 3.7 mS cm⁻¹,...

In situ chemical reduction using commercial zero valent iron microparticles (ZVIm) resulted to be an efficient technique for the removal of recalcitrant and toxic chlorinated organic compounds (COCs) dissolved in groundwater. Groundwater was obtained from Bailin’s landfill (Sabiñanigo, Spain), where liquid and solid wastes of an old lindane factory...

This paper presents a model for a reactive distillation column where 2-cyclohexen-1-one is eliminated from a mixture of cyclohexanone and cyclohexanol. In the purification of cyclohexanone, 2-cyclohexen-1-one must be removed to produce high quality caprolactam. A common practice in industry is to promote the condensation of 2-cyclohexen-1-one with...

The extensive use of the organochlorine pesticide lindane in the second half of the 20th century generated large volumes of wastes over the world. Among these wastes, a dense non-aqueous phase liquid (DNAPL), mainly composed of chlorobenzenes, hexachlorocyclohexanes and heptachlorocyclohexanes, was dumped in insecure landfills remaining in the subs...

α, β and γ-hexachlorocyclohexane (HCH) are persistent and bioaccumulative pollutants and they were included in the Stockholm Convention on Persistent Organic Pollutants (POPs). Old lindane factories generated high amounts of wastes with HCH and other Chlorinated Organic Compounds (COCS). These were often dumped in the surroundings of the production...

The present work studies the efficiency of alkaline activated persulfate (PS) to remediate an aged diesel fuel contaminated soil from a train maintenance facility. The Total Petroleum Hydrocarbon (TPH) concentration in soil was approximately 5000 mg kg− 1 with a ratio of aliphatic:aromatic compounds of 70:30. Aromatic compounds were mainly naphtale...

The effective removal of recalcitrant organochlorine pesticides including hexachlorocyclohexane (HCH) present in a real groundwater coming from a landfill of an old lindane (γ-HCH) factory was performed by electrochemical oxidation using a BDD anode and a carbon felt cathode. Groundwater (ΣHCHs = 0.42 mg L-1, TOC0 = 9 mg L-1, pH0 = 7, conductivity...

In this work, in situ chemical oxidation (ISCO) with alkali activated persulfate has been tested for the elimination of HCH isomers and other chlorinated compounds in groundwater from Sabiñanigo (Sardas landfill), which was contaminated by solid and liquid wastes illegally dumped in the area by a company producing lindane. Due to the site lithology...

This study focuses on the effect of electrode materials on abatement of lindane (an organochlorine pesticide) by electrooxidation process. Comparative performances of different anodic (platinum (Pt), dimensionally stable anode (DSA) and boron-doped diamond (BDD)) and cathodic (carbon sponge (CS), carbon felt (CF) and stainless steel (SS)) materials...

BACKGROUND Remediation of a soil polluted with fuel oil #2 and polycyclic aromatic hydrocarbons (PAHs) has been carried out by alkaline activated persulfate (PS). The effect of surfactant addition on the abatement of TPH and PAHs was studied. Accordingly, four runs were performed at flow conditions using: only water, only surfactant (15 g L ‐1 of V...

Lindane is an organochlorine pesticide broadly used in the last decades. It is persistent and recalcitrant in aquatic environments and difficult to biodegrade. This study is focused on the complete degradation of lindane by an electrochemical advanced oxidation process, the electro-Fenton (EF) process, using a BDD anode and carbon felt (CF) cathode...

Three persulfate (PS) activation methods (nanoparticles of zero-valent iron (nZVI), hydrogen peroxide and alkali) were compared using phenol as target pollutant. Firstly, four experiments were conducted at 25 °C in a batch way using the same initial phenol and oxidant concentrations (10 mM and 420 mM, respectively), being the molar ratio activator/...

Cyclohexanone (ONE) is an important raw material to promote caprolactam (CPL). It is used as a monomer in nylon industries. In the ONE production process, this component needs to be purified from a mixture of cyclohexanol (OL) and some impurities such as 2-cyclohexen-1-one (CXENONE). The concentration of these impurities must be reduced o in order...

This report is focused on the dechlorination of lindane, a recalcitrant and refractory pollutant, by zero valent iron microparticles (ZVIM) in batch and continuous mode. Experimental variables such as initial lindane concentration, ZVIM dosage and temperature were studied. Batch experiments indicate that the lindane dechlorination is enhanced with...

During the production of lindane (γ-HCH) large volumes of wastes containing α-, β-, and δ-HCH isomers were generated. Hexachlorocyclohexanes (HCHs) are carcinogens and teratogen compounds. Although their production and use are currently banned in most countries, many landfills and sites remain polluted by these compounds. This paper studies a promi...

Remediation of contaminated soils under flow-through conditions is an issue of great interest since it provides a better approach to real case applications than batch experiments. In this work, a column filled with soil, artificially spiked and aged for three months with Phenanthrene (PHE), Anthracene (ANT), Pyrene (PYR) and Benzo(a)pyrene (BaP), w...

Persulfate (PS) activated with iron to generate sulfate radicals was employed in the oxidation of Diuron (selected as an example of priority pollutant), Caffeine and Ibuprofen (examples of emerging pollutants whose consumption is widespread). The effect of iron valence (0, 2 and 3) and particle size of Zero-Valent Iron (ZVI) was studied in a batch...

Cyclohexanone oxime (ONEOX) is the precursor of ε-caprolactam, monomer used within the nylon-6 industry. This work studies the production of ONEOX from cyclohexanone (ONE) oximation with hydroxylammonium sulfate (HAS). The reaction involves two liquid phases: HAS is present in the aqueous phase, and ONEOX and ONE in the organic phase. The influence...

The vapor–liquid equilibrium (VLE) data at the constant pressure of P = 1 bar were determined for binary mixtures consisting of cyclohexanone + 2-cyclohexen-1-one and cyclohexanol + 2-cyclohexen-1-one. The thermodynamic consistency of the VLE data was verified with the Wisniak’s and area tests, with positive results. Experimental VLE data were fitt...

Contamination of soils by persistent pollutants is considered an important matter of increasing concern. In this work, activated persulfate (PS) was applied for the remediation of a soil contaminated with polycyclic aromatic hydrocarbons (PAHs), such as anthracene (ANT), phenanthrene (PHE), pyrene (PYR) and benzo[a]pyrene (BaP). PS activation was p...

Perfluorinated compounds (PFCs) are receiving significant attention due to its global distribution, high persistence, and bioaccumulation properties. Among them, perfluorooctanoic acid (PFOA) is one of the most commonly found in the environment. The strong bond C–F in PFOA is extremely difficult to degrade, therefore advanced oxidation processes (A...

BACKGROUNDA contaminated soil with 100 mg·kg−1 each of the following pollutants: anthracene (ANT), phenanthrene (PHE), pyrene (PYR) and benzo(a)pyrene (BaP) was treated by three different kinds of Fenton's reactions without pH adjustment, Fenton like reaction (hydrogen peroxide (H2O2) with a ferric iron salt (Fe(III)), Fenton catalyzed with nanopar...

Glycerol (GLY) etherification with benzyl alcohol (BA) was conducted with different zirconia-based heterogeneous acid catalysts, aiming to produce mono- (ME) and dibenzyl glycerol ethers (DE). Physicochemical properties of the prepared catalysts were obtained through XRD, SEM and adsorption of ammonia. The catalytic tests were performed at differen...

Background Modified Fenton reaction was used for the remediation of a soil polluted with ethylbenzene (EB), a toxic compound in gasoline. Fe(III) and trisodium citrate were used as catalyst and chelating agent, respectively. pH remains near-neutral in the process. Contaminant, chelating agent, oxidant and iron in solution were monitored at any time...

The present work studies the remediation of a B20 (20 % biodiesel, 80 % diesel) biodiesel blend-contaminated soil (1,000 mg kg−1) with persulfate activated by iron. Three different sources of iron (Fe(II)), granular zerovalent iron (gZVI), and a slurry of nanoparticles of zerovalent iron (nZVI), without pH adjustment were tested. Besides, the effec...

The kinetics of heterogeneously catalyzed self-condensation of cyclohexanone using Amberlyst 15 as a catalyst has been determined from data obtained in a batch reactor. Temperature and catalyst concentration ranges used were 70–110 °C and 6–66 gcat dry·kg–1, respectively. Runs were carried at both 5 bar of pressure, in order to avoid the evaporatio...

Persulfate (PS) activated by zero-valent iron (ZVI) to generate sulfate radicals (SO4 center dot-) was employed in the oxidation of Orange G (OG), an azo dye commonly found in textile wastewaters. Acidic corrosion and direct reaction with persulfate were considered for the oxidation of ZVI to Fe(II), both reactions taking place at the ZVI surface....

A soil contaminated with a B20 biodiesel blend (20 % biodiesel, 80 % diesel) has been treated by modified Fenton process with or without chelant addition. All experiments were conducted without pH adjustment. The reagents used were as follows: hydrogen peroxide as oxidant (400-4,000 mmol L(-1)), ferric ion as catalyst (5-20 mmol L(-1)), and trisodi...

Persulfate (PS) was employed in the oxidation of Orange G (OG), an azo dye commonly found in textile wastewaters. Activation of PS was conducted with iron to generate sulfate free radicals (SO4(-)) with high redox potential capable to oxidize most of the organics in water. Identification of oxidation intermediates was carried out by analyzing at di...

Catalytic diuron degradation in soil by modified Fenton or Fenton-like reaction has been studied and a kinetic model including the rates of all physical and chemical processes involved in both aqueous and soil phases has been developed and validated. The soil selected, a sandy clay loam one, was artificially spiked with a solution of diuron dissolv...

In the cyclohexanone purification process, some impurities, such as pentanal, hexanal, and 2-cyclohexen-1-one, must be removed in order to ensure good quality of nylon fibers in the caprolactam polymerization step. To do this, an industrial common practice is to add a homogeneous basic catalyst (such as sodium hydroxide, NaOH) to promote the conden...

A study of the influence of different catalysts on glycerol etherification with benzyl alcohol was performed. The best catalyst was selected based on activity and selectivity values. Experimental results were obtained at different reactant molar ratios (benzyl alcohol/glycerol = 3:1–1:3), temperatures (80–100 °C), and catalyst concentrations (3.45–...

The recovery of Tween 80 from a liquid residue, obtained after washing of a contaminated soil with p-Cresol, was studied by selective adsorption of p-Cresol with activated carbons. A modified expression of the Langmuir equation was succesfully used to predict the adsorption isotherms of p-Cresol in the absence and presence of different surfactant c...

BackgroundA study of the effect of different ion exchange resins, Amberlyst 15, Amberlite 200 and Amberlite IRC-50, on glycerol etherification with tert-butyl alcohol was performed. The best catalyst was selected based on the activity and selectivity values. The capability of reusing this catalyst after different pre-treatments was analysed. A kine...

Soil washing was applied to a contaminated soil with p-Cresol by using a nonionic surfactant (Tween 80). A mathematical model has also been proposed to describe both the pollutant desorption and the surfactant adsorption, taking place simultaneously. The effect of temperature (20–40 °C) and surfactant concentration (0.1–10 g L−1) have been analyzed...

A kinetic model to describe the dimer formation (D) in the process of cyclohexanone self-condensation was developed, including different variables such as temperature, catalyst concentration and equilibrium concentrations. Basic catalytic self-condensation of cyclohexanone in the liquid phase was conducted in a batch reactor by using sodium hydroxi...

A deactivation study of a commercial copper zinc oxide catalyst (T-2130, Süd-Chemie) used in dehydrogenation of cyclohexanol to cyclohexanone in the gas phase has been carried out. The experiments were performed in a continuous fixed bed reactor (tubular stainless steel, inner diameter 0.85 cm, length 25 cm), at 290 °C and atmospheric pressure, at...

In this work, abatement of diuron (D), (selected as an example of priority pollutant) and nicotine (N), caffeine (C), ibuprofen (I) and phenacetin (P), (chosen as examples of target emerging pollutants), have been carried out by using persulfate activated by Fe2+. Reactions were accomplished at room temperature in a batch or semicontinuous (SC) man...

The catalytic etherification of glycerol with tert-butyl alcohol over a strong acid ion-exchange commercial resin (Amberlyst 15) has been studied. The etherification reactions were carried out in a glass laboratory autoclave reactor with magnetic stirring without solvent at autogenous pressure. Experimental results were obtained at different temper...

In this study, a kinetic model (including reaction scheme and the kinetic parameters) for formation reactions of dehydrogenation impurities (2-cyclohexenone and phenol) was developed for the cyclohexanol and 2-cyclohexenol dehydrogenation processes. 2-Cyclohexenol used to be an impurity contained in commercial cyclohexanol. Runs were carried out at...

a b s t r a c t The use of catalyzed H 2 O 2 propagations (CHP) by the Fenton-like process has been evaluated for the treatment of contaminated soil by diuron ((q Diuron) o = 40 mg kg −1) at natural neutral pH. The interaction of H 2 O 2 with the soil in batch system has been previously studied at four different initial H 2 O 2 concen-tration (20,0...

Recently more attention has been paid to emerging pollutants in water. Among the treatments proposed for abatement of these compounds Advance Oxidation Processes (AOPs) have been used. Many studies are focused on elimination of the original pollutant and TOC while less attention has been paid for generated oxidation intermediates and their associat...

a b s t r a c t In situ chemical oxidation (ISCO) is a powerful technology for soil remediation. However, one of the main drawbacks of an in situ Fenton-like treatment (H 2 O 2 + natural Fe species present in soil) relies in the instability of H 2 O 2 when is in contact with soil. Besides, organic pollutants can be strongly entrapped on the soil or...

A kinetic model of phenol formation in the process of dehydrogenation of cyclohexanol to cyclohexanone has been developed and validated, including variables such as the temperature and the concentration of reactants and products. Catalytic dehydrogenation of cyclohexanol to cyclohexanone in the gas phase was conducted at atmospheric pressure in a c...

Soil washing is a potential technology for rapid removal of organic hydrocarbons sorbed to soils. In this work, p-cresol desorption with different non-ionic surfactants (Tween 80, Brij 30 and Triton X-100) was compared to cyclodextrine and citrate as solubilizer. A series of batch extraction experiments were conducted at 20°C using the field soil w...

a b s t r a c t In situ chemical oxidation (ISCO) seems to be a powerful technology for soil remediation. In this work the application of Fenton's like oxidation treatment (H 2 O 2 + natural ferrous species present in soil) has been evaluated to two different soils (S1 and S2) contaminated with phenol (q PhOH S1o = 360 mg g −1 , q PhOH S2o = 160 mg...

The elimination of pesticides by persulphate activated with Fe2+ showed high oxidation rates due to the oxidation effectiveness of persulphate free radicals (SO4−). Effects of iron addition policy, reaction temperature and persulphate concentration were studied employing diuron as target pollutant. Different amounts of Fe2+ (from 5 to 86 mg) were u...

Catalytic dehydrogenation of cyclohexanol to cyclohexanone has been carried out on phase gas in a continuous fixed bed reactor under atmospheric pressure. Copper chromite and copper zinc oxide catalysts have been checked. Effect of temperature (in the range 250–290°C) and spatial time in reactor have been studied. The catalytic activity has been ev...

The high oxidation efficiencies of the free radicals (SO4−), in combination with the slow rate of consumption of the oxidant, make this process very effective for the degradation of organic herbicides. Effects of pH, persulphate and Fe(II) concentration on the destruction of diuron by heat-assisted persulphate were examined in batch experiments. Al...

Catalytic wet oxidation (CWO) of 1000 mg/L of phenol (PhOH) aqueous solutions has been carried out using a commercial activated carbon as catalyst, placed in a continuous three-phase reactor at 16 bar, and temperature was changed in the interval 127−160 °C. Pure oxygen was fed as gaseous phase. Pollutant conversion, mineralization, intermediate dis...

A simplified pseudokinetic model to predict the mineralization evolution of organic pollutants by Fenton's reagent (FR) has been developed. The model has been validated by fitting phenol oxidation data by using FR in a batch way but could be applied to other wastewaters. The proposed model can be applied to the whole range of hydrogen peroxide dosa...

Rates of hydrogen peroxide decomposition were investigated in soils slurries. The interaction soil-hydrogen peroxide was studied using a slurry system at 20 degrees C and pH 7. To determine the role of soil organic matter (SOM) in the decomposition of hydrogen peroxide, several experiments were carried out with two soils with different SOM content...

A previously proposed lumped pseudokinetic model has been improved and applied to analyze the literature toxicity evolution data for phenol oxidation using different abatement technologies, such as electrochemical (EC) treatment, photocatalysis (PC), Fenton’s reagent (FR), and catalytic wet oxidation (CWO). It has been considered that phenol, P, re...

A lumped pseudokinetic model that is able to predict the toxicity change during the treatment of industrial wastewater as a function of the initial toxicity and temperature of the process is proposed. The original pollutant (or pollutant mixture), P, reacts to form a lumped intermediate species, I, which, in turn, reacts to form a nontoxic lumped s...

Hydrogen peroxide has been used to oxidize a sorbed aromatic contaminant in a loamy sand with 195.9 g kg(-1) of organic carbon by using iron as catalyst at 20 degrees C. The 2,4-dimethylphenol (2,4-DMP) was chosen as pollutant. Because of this soil generates a slightly basic pH in contact to an aqueous phase the solubility of the iron cation was de...

The sorption and mobility of trace metals in calcareous soils (calcaric Fluvisols) were studied in experimental columns using nine soil samples extracted from Ap and AC horizons, under laboratory conditions. A contaminating solution with six heavy metals at identical concentrations (350 mg kg − 1 for each metal) was used to saturate the soil column...

Several bioassays have been carried out to analyze the toxicity and biodegradability of several imidazolium ionic liquids (ILs) in aqueous phase. The synthetized compounds consist of an imidazolium cation with two alkyl substituents in positions 3 (R1) and 1 (R2) and a counter-ion. The alkyl substituent R1 has been fixed as a methyl group and the e...

Soil solution composition depends on the solid phase properties of soils. Therefore it is necessary to determine how soil and solution interact in order to understand the processes that influence ecosystems, such as plant nutrition or the movement of contaminants in soils. As the product of many interrelated factors, these interactions are very com...

Polymeric matrices of poly(2-hydroxyethyl methacrylate) (PHEMA) crosslinked with different percentages of ethylene glycol dimethacrylate (EGDMA) as well as different loads of nickel salt were synthesized. Nickel release from the polymeric systems, and their thermal stability were analyzed. A high percentage of the nickel loaded was released, althou...

The effects of exposure to high doses of lead on reproduction and development have been established, but not so those caused by low lead doses or the influence that life stage at which contact with the metal takes place might have. The aim of this work was to study the effects of 200 and 400 ppm lead acetate in drinking water on reproduction and de...