Person: Rodríguez Vega, Sergio
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First Name
Sergio
Last Name
Rodríguez Vega
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Ingeniería Química y de Materiales
Area
Ingeniería Química
Identifiers
5 results
Search Results
Now showing 1 - 5 of 5
Item Comparison of real wastewater oxidation with Fenton/Fenton-like and persulfate activated by NaOH and Fe(II)(Journal of Environmental Management, 2020) Rodríguez Vega, Sergio; Lorenzo Fernández, David; Santos López, Aurora; Romero Salvador, ArturoTreatment 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's reagent were carried out in a 0.25 L batch reactor at 25 °C by adding either Fe(II) or Fe(III) and H2O2 to an aqueous solution of wastewater, whose pH was previously adjusted to 2 or 3. Iron concentration ranging from 25 to 100 mg/L and peroxide concentration from 2500 to 10000 mg/L were used. The total organic carbon slightly decreased when WWFQ was treated. Moreover, better results were obtained when Fe(II) was used than Fe(III). Both iron concentration and oxidant dosage had a positive influence on the chemical oxygen demand (COD) removal, until an asymptotic value of 30% was obtained. Oxidation of pollutants contained in WWFQ was studied with persulfate (18.4–294 mM) activated with NaOH and Fe(II) (36.8–588 mM). Again, a positive influence of both persulfate and NaOH was observed, although a similar asymptotic COD value was observed. This parallelism between both technologies confirms recalcitrant compounds were obtained.Item Abatement of chlorinated compounds in groundwater contaminated by HCH wastes using ISCO with alkali activated persulfate(Science of The Total Environment, 2018) Santos López, Aurora; Jesús Fernández; Rodríguez Vega, Sergio; Domínguez Torre, Carmen María; Miguel Ángel Lominchar; Lorenzo Fernández, David; Romero Salvador, ArturoIn 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 and the type of pollutants found in groundwater (HCHs and chlorobenzenes) alkali (NaOH) activated persulfate (PS) was selected as oxidant. The influence of variables such as PS concentration (42–200 mM) and NaOH:PS molar ratio (2:1 to 4:1) on chlorinated compound abatement has been studied and a kinetic model to predict the composition of all chlorinated organic compounds (COCs) in the aqueous phase with time was obtained. It was found that a fast initial hydrodechlorination reaction took place in which HCH isomers reacted to trichlorobenzenes (mainly 1,2,4 TCB) at pH ≥ 12. Mono-, di-, tri and tetrachlorobenzenes remaining were oxidized without producing aromatic intermediates. At the condition tested a first order kinetic model for COCs and PS concentration was obtained. Zero order alkali concentration was obtained while pH was being kept at 12 for the whole reaction time.Item Degradation of Hexachlorocyclohexanes (HCHs) by Stable Zero Valent Iron (ZVI) Microparticles(Water, Air, & Soil Pollution, 2016) Domínguez Torre, Carmen María; Rodríguez Vega, Sergio; Lorenzo Fernández, David; Romero Salvador, Arturo; Santos López, AuroraDuring 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 promising and novel alternative for the HCH abatement: dechlorination by zero valent iron microparticles. Synthetic wastewater (0.5 mg/L of α-, β-, γ-, and δ-HCH or 6 mg/L of γ-HCH) and five types of commercial iron microparticles (here named mFe-1, mFe-2, mFe-3, mFe-4, and mFe-5) were used in batch (5 g/L) and continuous (W mFe/Q L = 167 g · h/L) operation mode at room temperature. Iron microparticles were characterized (before and after reaction) by N2 adsorption/desorption isotherms and X-ray diffraction. HCH isomers showed different behavior vs. dechlorination (γ > α > δ > β) according to the axial/equatorial position of the chlorines. The most active iron source among those tested was mFe-1, presenting small particle diameter (70 μm), moderate BET area (35 m2/kg), low oxygen content, and traces of manganese. mFe-1 exhibited high activity and stability both in continuous (X γ-HCH = 70%, W mFe/Q L = 167 g · h/L) and discontinuous (X γ-HCH = 100%, 48 h) operation. Contribution of HCH adsorption over iron microparticles was found negligible being benzene and Cl− the final dechlorination products.Item Kinetics of lindane dechlorination by zero valent iron microparticles: Effect of different salts and stability study.(Industrial and Engineering Chemistry Research, 2016) Domínguez Torre, Carmen María; Santos López, Aurora; Parchão, Joana; Rodríguez Vega, Sergio; Lorenzo Fernández, David; Romero Salvador, ArturoThis report is focused on the dechlorination of lindane, a recalcitrant and refractory pollutant, by zerovalent 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 the increase of ZVIM dosage and reaction temperature, and is maintained with increasing initial pollutant concentration. Kinetic analyses elucidated that lindane degradation followed a first order reaction for both pollutant and ZVIM concentration. The kinetic model can also accurately predict the results in continuous mode (more realistic conditions), where the high stability of ZVIM has been thoroughly demonstrated. Further studies indicated that coexistence of common ions can (i) not affect (SO42–, Na+, Ca2+, Mg+) or (ii) promote (HCO3–, Cl–) the lindane dechlorination process. The results implied that the use of ZVIM is a potential approach for in situ remediation of soil and groundwater lindane contamination.Item Kinetics of Lindane Dechlorination by Zerovalent Iron Microparticles: Effect of Different Salts and Stability Study(Industrial & Engineering Chemistry Research, 2016) Domínguez Torre, Carmen María; Parchão, Joana; Rodríguez Vega, Sergio; Lorenzo Fernández, David; Romero Salvador, Arturo; Santos López, AuroraThis report is focused on the dechlorination of lindane, a recalcitrant and refractory pollutant, by zerovalent 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 the increase of ZVIM dosage and reaction temperature, and is maintained with increasing initial pollutant concentration. Kinetic analyses elucidated that lindane degradation followed a first order reaction for both pollutant and ZVIM concentration. The kinetic model can also accurately predict the results in continuous mode (more realistic conditions), where the high stability of ZVIM has been thoroughly demonstrated. Further studies indicated that coexistence of common ions can (i) not affect (SO4 2−, Na+ , Ca2+, Mg+ ) or (ii) promote (HCO3 −, Cl−) the lindane dechlorination process. The results implied that the use of ZVIM is a potential approach for in situ remediation of soil and groundwater lindane contamination