Analysis of the characteristics of poultry slaughterhouse wastewater (PSW) and its treatability

Abstract

Abstract The first step towards selecting a suitable treatment option for poultry slaughterhouse wastewater (PSW) treatment is to characterize it. Various parameters such as the pH, tCOD, BOD5, TSS, FOG, turbidity, salinity or conductivity were analyzed in this study and provided values significantly higher than discharge limits imposed by various countries. Furthermore, the biodegradability index (BOD5/COD) of PSW was determined and averaged a value of 0.61 for the samples collected during normal processing operations in the slaughterhouse and 0.72 for samples collected during the cleaning of equipment after broiler processing operations. This good biodegradability translated to a good biological decomposition potential, which can be a risk for the environment as a result of untreated effluent, and also highlights the suitability of biological treatment processes for the treatment of such wastewater. Moreover, to reduce the production of chemical waste from the toxic reagents used for some analyses, and to alleviate the cost and the time required for these analyses, linear regressions were used to correlate three water quality parameters (tCOD, BOD5, and FOG), interchangeably. These linear regressions provided a good relationship between these parameters, with R2 > 0.9 for the samples collected during normal operation periods; and weaker correlation for the FOG/BOD5 and FOG/tCOD of samples collected during the cleaning of processing equipment. This was attributed to the high concentration of FOG (5,216 ± 2,534) in the samples collected during this period, from the collection of carcass debris and fats left on the equipment during the slaughtering.