Estudio comparativo de coagulantes - floculantes naturales y sustancias químicas tradicionales en el tratamiento de aguas residuales
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Fecha
2009-03
Autores
Guardián López, Róger Alonso
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Editor
Universidad Nacional (Costa Rica)
Resumen
En este estudio se compara el desempeño como coagulantes de dos compuestos químicos tradicionales: sulfato de aluminio y cloruro de hierro (III) y dos sustancias de origen natural: quitosano y semilla de tamarindo, en dos tipos de agua residual: una con alta turbidez, proveniente de la industria textil y otra con baja turbidez, del STAR de la Universidad Nacional, las que son principalmente del tipo sanitario o doméstico. Para ello se determinaron las dosis que generaban mayor remoción de turbidez y de DQO, mediante prueba de jarras (Jar Test). Además, se realizó un análisis de costos asociado a la adquisición y empleo de cada una de las sustancias estudiadas.
Los resultados obtenidos muestran que las sustancias de origen natural pueden remover turbidez y DQO al igual que lo hacen los compuestos químicos tradicionales, sin embargo, con eficiencias menores (cercanas a un 10% menor que el logrado por las sustancias coagulantes primarios, para ambos parámetros).
El quitosano presentó muy buena remoción de turbidez a pH neutro y básico, pero incrementó el DQO, mientras que la semilla de tamarindo funcionó a pH ligeramente ácido, y mostró mejores resultados en aguas con turbidez media (100 NTU) que en las de baja turbidez (16 NTU).
El análisis de costos de operación reveló que la mejor opción técnicoeconómica es el sulfato de aluminio ($0,28 y $0,41/ rn3 de agua residual "doméstica" y de la industria textil, respectivamente), seguido por la semilla de tamarindo ($0,75 y $O,48/m3) y el cloruro de hierro (III) ($0,88 y $1,17/m 3). El quitosano en las condiciones de pureza empleado en este estudio resulta inviable por su elevado costo ($9,93 y $11,49/m 3).
This study compares the performance as coagulants of two traditional chemical compounds: aluminum sulfate and iron (III) chloride and two substances of natural origin: chitosan and tamarind seed, in two types of wastewater: one with high turbidity, from the textile industry and another with low turbidity, from the STAR of the National University, which are mainly of the sanitary or domestic type. To do this, the doses that generated the greatest removal of turbidity and COD were determined, using a jar test (Jar Test). In addition, a cost analysis associated with the acquisition and use of each of the substances studied was carried out. The results obtained show that substances of natural origin can remove turbidity and COD in the same way as traditional chemical compounds do, however, with lower efficiencies (close to 10% lower than that achieved by primary coagulant substances, for both parameters). ). Chitosan presented very good turbidity removal at neutral and basic pH, but increased COD, while tamarind seed worked at slightly acidic pH, and showed better results in medium turbidity waters (100 NTU) than in low turbidity ones. (16 NTU). The analysis of operating costs revealed that the best techno-economic option is aluminum sulfate ($0.28 and $0.41/m3 of "domestic" wastewater and from the textile industry, respectively), followed by tamarind seed ($0 .75 and $0.48/m3) and iron(III) chloride ($0.88 and $1.17/m3). Chitosan in the purity conditions used in this study is unfeasible due to its high cost ($9.93 and $11.49/m3).
This study compares the performance as coagulants of two traditional chemical compounds: aluminum sulfate and iron (III) chloride and two substances of natural origin: chitosan and tamarind seed, in two types of wastewater: one with high turbidity, from the textile industry and another with low turbidity, from the STAR of the National University, which are mainly of the sanitary or domestic type. To do this, the doses that generated the greatest removal of turbidity and COD were determined, using a jar test (Jar Test). In addition, a cost analysis associated with the acquisition and use of each of the substances studied was carried out. The results obtained show that substances of natural origin can remove turbidity and COD in the same way as traditional chemical compounds do, however, with lower efficiencies (close to 10% lower than that achieved by primary coagulant substances, for both parameters). ). Chitosan presented very good turbidity removal at neutral and basic pH, but increased COD, while tamarind seed worked at slightly acidic pH, and showed better results in medium turbidity waters (100 NTU) than in low turbidity ones. (16 NTU). The analysis of operating costs revealed that the best techno-economic option is aluminum sulfate ($0.28 and $0.41/m3 of "domestic" wastewater and from the textile industry, respectively), followed by tamarind seed ($0 .75 and $0.48/m3) and iron(III) chloride ($0.88 and $1.17/m3). Chitosan in the purity conditions used in this study is unfeasible due to its high cost ($9.93 and $11.49/m3).
Descripción
Guardián López, R. A. (2009). Estudio comparativo de coagulantes - floculantes naturales y sustancias químicas tradicionales en el tratamiento de aguas residuales. [Tesis de Licenciatura]. Universidad Nacional, Heredia, C.R.
Palabras clave
COAGULANTES, QUITOSANO, CHITOSAN, SEMILLA, EFLUENTES, SEED