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Examinando Artículos por Autor "Arbelaez, Paula Eliana"
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Ítem The electrochemical elimination of coliforms from water using BBD/Ti or graphite anodes: A comparative study(International Water Association Publishing, 2018-04-01) Gil Pavas, E.; Arbelaez, Paula Eliana; Medina, J.; Dobrosz-Gómez, I.; Angel Gomez-Garcia, Miguel; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de ProcesosThe elimination of total and fecal coliforms, from raw surface water, was carried out by electrochemical oxidation using either boron doped diamond (BDD/Ti) or graphite (GP) anodes, in a chloride-free medium. The optimal values of the operation parameters, maximizing the coliform elimination percentage, were determined using statistical experimental design. The current density ( j: 2-20 mA/cm2), the conductivity (s: 500-900 µS/cm) and the anode materials (An) were considered as variables to perform the Box-Behnken experimental design together with the response surface methodology analysis for optimization. The statistical analysis indicated that, in the evaluated range, the disinfection efficiency increased with an increase in j and decreased with an increase in s. The following optimal conditions for the elimination of total and fecal coliforms were found: j: 10 mA/cm2, s: 500 µS/cm and BDD/Ti used as anode material. The BDD/Ti electrode let to achieve complete coliform elimination after ca. 20 min of reaction while the GP one needed ca. 27 min. In water treated with both BDD/Ti and GP anode, after 7 days, any coliforms growth was observed. As a result of the oxidation process, the total organic carbon and nitrite concentration decreased while nitrate concentration increased. © IWA Publishing 2018.Ítem TRATAMIENTO DE AGUAS RESIDUALES DE LA INDUSTRIA TEXTIL MEDIANTE COAGULACION QUIMICA ACOPLADA A PROCESOS FENTON INTENSIFICADOS CON ULTRASONIDO DE BAJA FRECUENCIA(Centro de Ciencias de la Atmosfera, UNAM, 2018-02-01) GIL PAVAS EDISON; Arbelaez, Paula Eliana; Medina, J.; GOMEZ, CARLOS MARIO; Universidad EAFIT. Departamento de Ingeniería de Procesos; Desarrollo y Diseño de ProcesosThe present study evaluates the sequential treatment of chemical coagulation (CC) followed by the advanced oxidation process (AOP) of Fenton (H2O2/Fe2+) or photoFenton (UV/H2O2/Fe2+) intensified by low frequency ultrasound. Optimization of the pretreatment step through CC by jar test showed that an optimal coagulant (Al-2[SO4](3)) dose of 800 mg/L removed 99 % of turbidity and 53 % of the chemical oxygen demand (COD). The resulting supernatant is used for the AOP evaluation. The statistical analysis of a Box-Behnken response surface design showed that optimal conditions to carry out the US/H2O2/Fe2+ process are: 1 mM de Fe2+, 14 mM de H2O2 and pH 3. Under these conditions the CC coupled to the US/H2O2/Fe2+ process removes 82 % of the COD of the supernatant while the US/UV/H2O2/Fe2+ process eliminates 95 % after 90 min of reaction. The use of ultrasound waves inducing an increase of 10 % in the process efficiency. The mineralization of pollutants during treatment as well as the H2O2 consumption were monitored.