In the rural regions of Latin America, wastewater treatment systems are based on conventional technologies such as the septic tanks. These treatment systems do not support biodegradability indexes lower than 0,4 measured in the form of BOD5/COD, values obtained when refractory contaminants are found in water; which in turn are associated in most cases with the intrusion of industrial wastewater. In these cases, the conventional treatment systems do not meet the regulations for which they were designed; and therefore public investment is lost to build them. This is why in the present investigation the biodegradability index of this type of effluents was increased, for which domestic wastewater mixed with leachate and industrial effluent obtained from the Chasinato creek in the Tungurahua province of Ecuador was used, in which a biodegradability index of 0,22 was obtained in BOD5/COD. An advanced oxidation process of modified Fenton was applied to this effluent, which increased the biodegradability index and avoided reducing the pH, since in large volumes this is very expensive. The optimal concentrations of reagents were FeSO4/H2O2 = 1 and C6H8O7/H2O2 = 2; with the addition of 10 mg/L of H2O2, which increased the biodegradability index to a value of 0,46, which is a satisfactory value to be treated in conventional systems such as septic tanks; in addition to a reduction of BOD5 and COD in efficiencies of 12.54%; 44.4% respectively.
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En las regiones rurales de América Latina y el Caribe, la cobertura de sistemas de alcantarillado fue del 64 % para el año 2015 (Lentini, 2015), llegándo-se a tratar el agua residual en un 34 % (UNESCO, 2017). La mayoría de estos sistemas de tratamiento son plantas convencionales construidas en las eta-pas finales de los sistemas de alcantarillado, los cua-les se ubican antes de una descarga a cuerpos de agua. Estos sistemas de tratamiento se basan en tec-nologías de remoción de baja carga contaminante y bajo costo de construcción y operación. La tecnolo-gía más usada es la fosa séptica, construida general-mente de concreto o plástico (Jouravlev, 2004).
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