Evaluación de diferentes tipos de cal y digestor enzimático de rastrojos en la disminución de coliformes fecales en lodos provenientes de la Planta de Tratamiento de Aguas Residuales de San Luis Talpa, La Paz, El Salvador

Abstract

The research was carried out at the Experimental and Practical Station of the Faculty of Agronomic Sciences of the University of El Salvador (UES), located in Tecualuya, municipality of San Luis Talpa, department of La Paz, El Salvador; Starting on March 19 and ending on September 30, 2. Hydrated lime, agricultural lime and Gypsum lime and three doses of an Enzymatic Digestor were evaluated in order to reduce concentrations of Fecal Coliforms in sludge from the Wastewater Treatment Plant of the municipality of San Luis Talpa, La Paz , El Salvador, which is administered by the National Aqueduct and Sewerage Administration (ANDA), and determine if they comply with the Mexican Standard NOM-004-SEMARNAT-2002, so that they can be used in agriculture without risks of contamination. The fecal coliform concentrations after 26 days of the sludge in the treatment plants drying yards and before establishing the different treatments were 23,105,000 NMP/g, according to the results of the laboratory analysis of the Research Center And Development in Health (CENSALUD), UES. The Mexican Standard NOM-004-SEMARNAT-2002 classifies the sludge with that concentration of fecal coliforms in class "C", which means that they can not be used in agriculture. The most effective treatment of the research after 40 days of applied treatments, which is the time required for the lime and the enzymatic digester to have their effect, is the application of two pounds of Hydrated lime plus 0.61 cc of Enzymatic Digester in nine Pounds of sludge, which reduced fecal coliform populations by up to 99.97% in sludge from the San Luis Talpa Wastewater Treatment Plant, compared to the control, which allows them to be used in agriculture.