Examinando por Materia "Toxicity"

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    Ítem
    Efficient treatment for textile wastewater through sequential electrocoagulation, electrochemical oxidation and adsorption processes: Optimization and toxicity assessment
    (Elsevier BV, 2020-01-01) GilPavas E.; Dobrosz-Gómez I.; Gómez-García M.-Á.; GilPavas E.; Dobrosz-Gómez I.; Gómez-García M.-Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In this work, the sequential Electrocoagulation + Electro-oxidation + Activated carbon adsorption (EC + EO + AC) process was studied as an alternative for the treatment of an industrial textile wastewater (TWW) issuing from a manufacturing company located in Medellín (Colombia). The EC's and EO's operational conditions were optimized using a Box-Behnken experimental design, the Response Surface Methodology and a constrained nonlinear optimization algorithm in terms of organic matter degradation efficiency. The best performance for EC (i. e., dye removal = 94%, COD and TOC degradation of 45 and 40%, respectively) was obtained using Fe anode and Boron Doped Diamond (BDD) cathode, with current density, jEC, equals to 5 mA/cm2, pH = 9.3, 60 RPM and 10 min of electrolysis. After EC treatment, the effluent biodegradability (evaluated as the BOD5/COD ratio) increases from 0.14 to 0.23. Regrettably, EC was not effective for the removal of acute toxicity to Artemia salina since the treated effluent remained very toxic (100%). The treatment of EC's effluent by EO enhanced organic pollutant removal. For EC + EO sequential process, EO optimal operational conditions (jEO = 10 mA/cm2, pH = 3, 240 RPM, BDD as anode and Fe as cathode) allowed reduction of 100% of color, 88% of COD and 79% of TOC after 30 min of electrolysis. Moreover, the BOD5/COD ratio increased from 0.23 to 0.58; however, the treated effluent remained very toxic to the Artemia salina. Consequently, an activated carbon adsorption step was included to complete the treatment process. Thus, by coupling the EC + EO + AC process, effluent's acute toxicity decreased completely. From molecular weight distribution analysis, it was concluded that EC + EO was efficient in eliminating low molecular weight (< 5 kDa) compounds. Finally, the operation cost, which includes chemical reagents, electrodes, energy consumption, and sludge disposal, for the EC + EO + AC sequential process was estimated in 3.83 USD /m3. © 2020 Elsevier B.V.
  • No hay miniatura disponible
    Ítem
    Efficient treatment for textile wastewater through sequential electrocoagulation, electrochemical oxidation and adsorption processes: Optimization and toxicity assessment
    (Elsevier BV, 2020-01-01) GilPavas E.; Dobrosz-Gómez I.; Gómez-García M.-Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    In this work, the sequential Electrocoagulation + Electro-oxidation + Activated carbon adsorption (EC + EO + AC) process was studied as an alternative for the treatment of an industrial textile wastewater (TWW) issuing from a manufacturing company located in Medellín (Colombia). The EC's and EO's operational conditions were optimized using a Box-Behnken experimental design, the Response Surface Methodology and a constrained nonlinear optimization algorithm in terms of organic matter degradation efficiency. The best performance for EC (i. e., dye removal = 94%, COD and TOC degradation of 45 and 40%, respectively) was obtained using Fe anode and Boron Doped Diamond (BDD) cathode, with current density, jEC, equals to 5 mA/cm2, pH = 9.3, 60 RPM and 10 min of electrolysis. After EC treatment, the effluent biodegradability (evaluated as the BOD5/COD ratio) increases from 0.14 to 0.23. Regrettably, EC was not effective for the removal of acute toxicity to Artemia salina since the treated effluent remained very toxic (100%). The treatment of EC's effluent by EO enhanced organic pollutant removal. For EC + EO sequential process, EO optimal operational conditions (jEO = 10 mA/cm2, pH = 3, 240 RPM, BDD as anode and Fe as cathode) allowed reduction of 100% of color, 88% of COD and 79% of TOC after 30 min of electrolysis. Moreover, the BOD5/COD ratio increased from 0.23 to 0.58; however, the treated effluent remained very toxic to the Artemia salina. Consequently, an activated carbon adsorption step was included to complete the treatment process. Thus, by coupling the EC + EO + AC process, effluent's acute toxicity decreased completely. From molecular weight distribution analysis, it was concluded that EC + EO was efficient in eliminating low molecular weight (< 5 kDa) compounds. Finally, the operation cost, which includes chemical reagents, electrodes, energy consumption, and sludge disposal, for the EC + EO + AC sequential process was estimated in 3.83 USD /m3. © 2020 Elsevier B.V.
  • No hay miniatura disponible
    Ítem
    Optimization and toxicity assessment of a combined electrocoagulation, H2O2/Fe2+/UV and activated carbon adsorption for textile wastewater treatment
    (Elsevier, 2019-02-15) GilPavas, E; Dobrosz-Gomez, I; Gomez-Garcia, MA; GilPavas, E; Dobrosz-Gomez, I; Gomez-Garcia, MA; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In this study, the potential application of sequential Electrocoagulation + Fenton (F) or Photo-Fenton (PF) + Active carbon adsorption (EC + F/PF + AC) processes were analyzed as alternatives for the treatment of an industrial textile wastewater resulting from an industrial facility located in Medellín (Colombia). In order to maximize the organic matter degradation, each step of the treatment was optimized using the Response Surface Methodology. At first, the optimal performance of EC was achieved with Fe electrodes operating at pH = 7, jEC = 10 mA/cm2 and 60 rpm, during 10 min of electrolysis. At these conditions, EC let to remove 94% of the dye's color, 56% of the COD and 54% of the TOC. Next, sequentially applied Fenton or photo-Fenton process (i.e., EC + F/PF), operating at the optimized conditions (pH = 4.3, [Fe2+] = 1.1 mM, [H2O2] = 9.7 mM, stirring velocity = 100 rpm and reaction time = 60 min.), improved the quality of the treated effluent. The EC + F let to achieve total color reduction, as well as COD and TOC removals of 72 and 75%, respectively. The EC + PF reached 100% of color, 76% of COD and 78% of TOC reductions. The EC + F/PF processes were more efficient than EC in elimination of low molecular weight (<5 kDa) compounds from wastewater. Moreover, the BOD5/COD ratio increased from 0.21 to 0.42 and from 0.21 to 0.46 using EC + F and EC + PF processes, respectively. However, EC + F/PF were not fully effective for the removal of acute toxicity to Artemia salina: 20% and 60% of reduction in toxicity using EC + F and EC + PF, respectively, comparing to very toxic (100%) raw textile wastewater. Thus, activated carbon adsorption was applied as an additional step to complete the treatment. After AC adsorption, the acute toxicity decreased to 10% and 0% using EC + F and EC + PF, respectively. The total operational costs, including chemical reagents, electrodes, energy consumption and sludge disposal, were of 1.65 USD/m3 and 2.3 USD/m3 for EC + F and EC + PF, respectively. © 2018 Elsevier B.V.
  • No hay miniatura disponible
    Ítem
    Optimization and toxicity assessment of a combined electrocoagulation, H2O2/Fe2+/UV and activated carbon adsorption for textile wastewater treatment
    (Elsevier, 2019-02-15) GilPavas, E; Dobrosz-Gomez, I; Gomez-Garcia, MA; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    In this study, the potential application of sequential Electrocoagulation + Fenton (F) or Photo-Fenton (PF) + Active carbon adsorption (EC + F/PF + AC) processes were analyzed as alternatives for the treatment of an industrial textile wastewater resulting from an industrial facility located in Medellín (Colombia). In order to maximize the organic matter degradation, each step of the treatment was optimized using the Response Surface Methodology. At first, the optimal performance of EC was achieved with Fe electrodes operating at pH = 7, jEC = 10 mA/cm2 and 60 rpm, during 10 min of electrolysis. At these conditions, EC let to remove 94% of the dye's color, 56% of the COD and 54% of the TOC. Next, sequentially applied Fenton or photo-Fenton process (i.e., EC + F/PF), operating at the optimized conditions (pH = 4.3, [Fe2+] = 1.1 mM, [H2O2] = 9.7 mM, stirring velocity = 100 rpm and reaction time = 60 min.), improved the quality of the treated effluent. The EC + F let to achieve total color reduction, as well as COD and TOC removals of 72 and 75%, respectively. The EC + PF reached 100% of color, 76% of COD and 78% of TOC reductions. The EC + F/PF processes were more efficient than EC in elimination of low molecular weight (<5 kDa) compounds from wastewater. Moreover, the BOD5/COD ratio increased from 0.21 to 0.42 and from 0.21 to 0.46 using EC + F and EC + PF processes, respectively. However, EC + F/PF were not fully effective for the removal of acute toxicity to Artemia salina: 20% and 60% of reduction in toxicity using EC + F and EC + PF, respectively, comparing to very toxic (100%) raw textile wastewater. Thus, activated carbon adsorption was applied as an additional step to complete the treatment. After AC adsorption, the acute toxicity decreased to 10% and 0% using EC + F and EC + PF, respectively. The total operational costs, including chemical reagents, electrodes, energy consumption and sludge disposal, were of 1.65 USD/m3 and 2.3 USD/m3 for EC + F and EC + PF, respectively. © 2018 Elsevier B.V.
  • No hay miniatura disponible
    Ítem
    Optimization of the heterogeneous electro-Fenton process assisted by scrap zero-valent iron for treating textile wastewater: Assessment of toxicity and biodegradability
    (Elsevier Ltd, 2019-12-01) GilPavas, Edison; Correa-Sanchez, Santiago; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    In this work, the heterogeneous electro-Fenton process assisted by scrap zero-valent iron (SZVI) and with graphite electrodes (as anode and cathode) is studied as an alternative way to treat wastewater from a textile plant located in Medellin, Colombia. The effects of the initial pH, SZVI load, and current density in the SZVI-assisted electro-oxidation process (EO/SZVI) are analyzed and optimized using multivariable regression models generated using the Box-Behnken experimental design and convex nonlinear optimization. The EO/SZVI process leads to maximum reductions of approximately 100%, 67%, and 59% in color, chemical oxygen demand (COD), total organic carbon (TOC), respectively, under the optimal operating conditions of pH of 3.5. Further, it leads to an SZVI concentration of 0.6 g/L, and a current density of 20 mA/cm(2) during 30 min of electrolysis. The post-process pollutants are characterized further using molecular weight distribution measurements, ultraviolet-visible spectroscopy, high-performance liquid chromatography, biodegradability, and toxicity. The results show that the treated effluent is polluted mostly by carboxylic acids of low molecular weight. A remarkable enhancement of the biodegradability of the effluent is evidenced by an increase in the BOD (5)/COD ratio (biodegradability index) from 0.15 to 0.54. Although the EO/SZVI process does not improve the toxicity (as measured by the mortality of Artemia salina), the latter is reduced subsequently from 100% to 20% through adsorption using activated carbon (AC). The findings of this study indicate that the EO/SZVI process is an effective and promising alternative for treating textile wastewater.
  • No hay miniatura disponible
    Ítem
    Optimization of the heterogeneous electro-Fenton process assisted by scrap zero-valent iron for treating textile wastewater: Assessment of toxicity and biodegradability
    (Elsevier Ltd, 2019-08-26) Gil, E.; Gil, E.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In this work, the heterogeneous electro-Fenton process assisted by scrap zero-valent iron (SZVI) and with graphite electrodes (as anode and cathode) is studied as an alternative way to treat wastewater from a textile plant located in Medellín, Colombia. The effects of the initial pH, SZVI load, and current density in the SZVI-assisted electro-oxidation process (EO/SZVI) are analyzed and optimized using multivariable regression models generated using the Box–Behnken experimental design and convex nonlinear optimization. The EO/SZVI process leads to maximum reductions of approximately 100%, 67%, and 59% in color, chemical oxygen demand (COD), total organic carbon (TOC), respectively, under the optimal operating conditions of pH of 3.5. Further, it leads to an SZVI concentration of 0.6 g/L, and a current density of 20 mA/cm2 during 30 min of electrolysis. The post-process pollutants are characterized further using molecular weight distribution measurements, ultraviolet–visible spectroscopy, high-performance liquid chromatography, biodegradability, and toxicity. The results show that the treated effluent is polluted mostly by carboxylic acids of low molecular weight. A remarkable enhancement of the biodegradability of the effluent is evidenced by an increase in the BOD5/COD ratio (biodegradability index) from 0.15 to 0.54. Although the EO/SZVI process does not improve the toxicity (as measured by the mortality of Artemia salina), the latter is reduced subsequently from 100% to 20% through adsorption using activated carbon (AC). The findings of this study indicate that the EO/SZVI process is an effective and promising alternative for treating textile wastewater. © 2019 Elsevier Ltd
  • No hay miniatura disponible
    Ítem
    Optimization of the heterogeneous electro-Fenton process assisted by scrap zero-valent iron for treating textile wastewater: Assessment of toxicity and biodegradability
    (Elsevier Ltd, 2019-08-26) Gil, E.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    In this work, the heterogeneous electro-Fenton process assisted by scrap zero-valent iron (SZVI) and with graphite electrodes (as anode and cathode) is studied as an alternative way to treat wastewater from a textile plant located in Medellín, Colombia. The effects of the initial pH, SZVI load, and current density in the SZVI-assisted electro-oxidation process (EO/SZVI) are analyzed and optimized using multivariable regression models generated using the Box–Behnken experimental design and convex nonlinear optimization. The EO/SZVI process leads to maximum reductions of approximately 100%, 67%, and 59% in color, chemical oxygen demand (COD), total organic carbon (TOC), respectively, under the optimal operating conditions of pH of 3.5. Further, it leads to an SZVI concentration of 0.6 g/L, and a current density of 20 mA/cm2 during 30 min of electrolysis. The post-process pollutants are characterized further using molecular weight distribution measurements, ultraviolet–visible spectroscopy, high-performance liquid chromatography, biodegradability, and toxicity. The results show that the treated effluent is polluted mostly by carboxylic acids of low molecular weight. A remarkable enhancement of the biodegradability of the effluent is evidenced by an increase in the BOD5/COD ratio (biodegradability index) from 0.15 to 0.54. Although the EO/SZVI process does not improve the toxicity (as measured by the mortality of Artemia salina), the latter is reduced subsequently from 100% to 20% through adsorption using activated carbon (AC). The findings of this study indicate that the EO/SZVI process is an effective and promising alternative for treating textile wastewater. © 2019 Elsevier Ltd
  • No hay miniatura disponible
    Ítem
    Optimization of the heterogeneous electro-Fenton process assisted by scrap zero-valent iron for treating textile wastewater: Assessment of toxicity and biodegradability
    (Elsevier Ltd, 2019-12-01) GilPavas, Edison; Correa-Sanchez, Santiago; GilPavas, Edison; Correa-Sanchez, Santiago; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    In this work, the heterogeneous electro-Fenton process assisted by scrap zero-valent iron (SZVI) and with graphite electrodes (as anode and cathode) is studied as an alternative way to treat wastewater from a textile plant located in Medellin, Colombia. The effects of the initial pH, SZVI load, and current density in the SZVI-assisted electro-oxidation process (EO/SZVI) are analyzed and optimized using multivariable regression models generated using the Box-Behnken experimental design and convex nonlinear optimization. The EO/SZVI process leads to maximum reductions of approximately 100%, 67%, and 59% in color, chemical oxygen demand (COD), total organic carbon (TOC), respectively, under the optimal operating conditions of pH of 3.5. Further, it leads to an SZVI concentration of 0.6 g/L, and a current density of 20 mA/cm(2) during 30 min of electrolysis. The post-process pollutants are characterized further using molecular weight distribution measurements, ultraviolet-visible spectroscopy, high-performance liquid chromatography, biodegradability, and toxicity. The results show that the treated effluent is polluted mostly by carboxylic acids of low molecular weight. A remarkable enhancement of the biodegradability of the effluent is evidenced by an increase in the BOD (5)/COD ratio (biodegradability index) from 0.15 to 0.54. Although the EO/SZVI process does not improve the toxicity (as measured by the mortality of Artemia salina), the latter is reduced subsequently from 100% to 20% through adsorption using activated carbon (AC). The findings of this study indicate that the EO/SZVI process is an effective and promising alternative for treating textile wastewater.
  • No hay miniatura disponible
    Ítem
    Using scrap zero valent iron to replace dissolved iron in the Fenton process for textile wastewater treatment: Optimization and assessment of toxicity and biodegradability
    (Elsevier Ltd., 2019-09-01) GilPavas, Edison; Correa-Sanchez, Santiago; Acosta, Diego A.; GilPavas, Edison; Correa-Sanchez, Santiago; Acosta, Diego A.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
    A Fenton like advanced oxidation process (AOP) employing scrap zerovalent iron (SZVI) and hydrogen peroxide (H2O2) was studied for industrial textile wastewater treatment from a textile manufacturing plant located at Medellin, Colombia (South America). The wastewater effluent studied contains a mixture of organic compounds resistant to conventional treatments. The effect of initial pH and SZVI concentration and H2O2 concentration were studied by a response surface methodology (RSM) Box-Behnken design of experiment (BBD). The combined SZVI/H2O2 process led to reductions of 95% color, 76% of chemical oxygen demand (COD) and 71% of total organic carbon (TOC) at optimal operating conditions of pH = 3, SZVI = 2000 mg/L and [H2O2] = 24.5 mM. Molecular weight distribution measurement (MWD), ultraviolet-visible (UV-Vis) spectroscopy, HPLC, biodegradability and toxicity were used to characterize the pollutants after the treatment process finding that the resulting effluent was polluted mostly by low molecular weight carboxylic acids. A remarkable biodegradability enhancement of the effluent was evidenced by a BOD5/COD ratio increase from 0.22 to 0.4; also, the SZVI/H2O2 process successfully reduced the toxicity from 60% to 20% of dead A. Salina crustaceans. (C) 2019 Elsevier Ltd. All rights reserved.
  • No hay miniatura disponible
    Ítem
    Using scrap zero valent iron to replace dissolved iron in the Fenton process for textile wastewater treatment: Optimization and assessment of toxicity and biodegradability
    (Elsevier Ltd., 2019-09-01) GilPavas, Edison; Correa-Sanchez, Santiago; Acosta, Diego A.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de Procesos
    A Fenton like advanced oxidation process (AOP) employing scrap zerovalent iron (SZVI) and hydrogen peroxide (H2O2) was studied for industrial textile wastewater treatment from a textile manufacturing plant located at Medellin, Colombia (South America). The wastewater effluent studied contains a mixture of organic compounds resistant to conventional treatments. The effect of initial pH and SZVI concentration and H2O2 concentration were studied by a response surface methodology (RSM) Box-Behnken design of experiment (BBD). The combined SZVI/H2O2 process led to reductions of 95% color, 76% of chemical oxygen demand (COD) and 71% of total organic carbon (TOC) at optimal operating conditions of pH = 3, SZVI = 2000 mg/L and [H2O2] = 24.5 mM. Molecular weight distribution measurement (MWD), ultraviolet-visible (UV-Vis) spectroscopy, HPLC, biodegradability and toxicity were used to characterize the pollutants after the treatment process finding that the resulting effluent was polluted mostly by low molecular weight carboxylic acids. A remarkable biodegradability enhancement of the effluent was evidenced by a BOD5/COD ratio increase from 0.22 to 0.4; also, the SZVI/H2O2 process successfully reduced the toxicity from 60% to 20% of dead A. Salina crustaceans. (C) 2019 Elsevier Ltd. All rights reserved.