Evaluation of Poultry Slaughterhouse Effluent Characteristics and Associated Potential Environmental Pollutions

Abstract

Wastewater generated from slaughterhouses pose a significant environmental concern due to their high organic matter content and other pollutants which are generated from slaughtering and processing of chickens, including stunning and slaughtering, washing, cleaning, defeathering, deboning and waste disposal. The characteristics of these effluents vary but usually have high concentration of COD, BOD, TDS and nutrients. Thus, this study aimed at characterizing effluents from three chicken slaughethouse located in Dar es Salaam city to establish the concentrations of various contaminants and potential environmental pollutions. The effluents were sampled from the discharge points of three chicken slaughterhouses in Dar es Salaam, Tanzania and transported to Ardhi University in the School of Engineering and Environmental Studies laboratory for analysis. The characterization involved physical, chemical, and heavy metal parameters using DR/4000 spectrophotometer and Atomic Absorption Spectrophotometer (AAS). Results indicated that the effluents had high concentration of COD (45 ± 6.4 to 1917 ± 54.7) mg/L, BOD (32 ± 21.7 to 1533 ± 87.8) mg/L, EC (3529 ± 178.2 to 7215 ± 257.8 µS/cm), NH3-N (2.89 ± 1.6 to 35.3 ± 6.4) mg/L, PO43- (7.59 ± 1.2 to 20.38 ± 4.1) mg/L and Pb (0.026 ± 0.011 to 0.048 ± 0.012) mg/L. Some parameters particularly turbidity, EC, TDS, Colour, NH3-N, PO43-, COD, BOD and Pb exceeded Tanzania municipal andindustrial wastewaters standards especially samples from S1 and S2 leading to environmental pollutions and affect aquatic organisms. Principal Component Analysis (PCA) confirmed that EC, TDS, COD and BOD were the main drivers contributing high loading rates in sampled effluents. This study, recommends effective treatment of the effluent prior discharge and ensure environmental regulations compliance.