Abstract

Total nitrous oxide (N2 O) emissions from a conventional active sludge process were calculated using a mathematical emission model and dissolved N2 O in the water phase by a N2 O water sensor. Calculated emissions showed good agreement with measured emissions based on concentrations and airflow in the off-gas ventilation system from the covered process. Various tests for a wide range of potentially affecting parameters indicated robust and reliable emission estimations by the model. Thus, common uncertainties in input data would still provide good emission estimations. Measurements of dissolved N2 O required low maintenance and N2 O emission monitoring based on such measurements might therefore be considered as a significant practical improvement. This would be advantageous especially in non-enclosed wastewater treatment plants (WWTPs) otherwise requiring complex off-gas measurements. As the sensor is connected directly to the WWTPs monitoring and control system, emissions calculations could be incorporated.

Abstract

Water is a resource used by mankind for industrial and domestic needs, which once used, is discharged into the public sewer system or septic tanks. This project proposes an ecological alternative for the treatment of wastewater from domestic use named Biofilter, which is built of living material (worms) and inert material (chip and gravel), which filters the wastewater; the biological filter has shown high efficiency in the removal of organic matter and pathogens. The field work was carried out with experimental biological filters, to ascertain the best composition of inert material, different variants were used. Two experimental Biofilters, one using sawdust and the other coco fiber were used in the treatment of domestic wastewater; treated samples from each reactor were subjected to laboratory analysis. The analysis and interpretation of results showed that the Biofilter using sawdust removed 53.53 % of pollutants and is outside the required norm for wastewater treatment and the Biofilter using coco fiber removed 82.37 % of contaminants and is within the Environmental Quality Norm and Effluent Discharge: Water Resource.