Abstract:
Poultry slaughterhouse wastewater is characterized by high pollution strength, making its
treatment before discharge or recycling of great importance. This study investigated the potential
influence of mixing ratios on the treatability of poultry slaughterhouse wastewater under three
different mixing ratios; 20:80, 50:50, and 80:20 of defeathering and cooling sources, respectively.
Wastewater samples were collected from the Izhevski production corporate (PC) poultry farm
located in the Akmola region, Kazakhstan. The lab-scale treatment plant, designed to simulate the
industrial-scale treatment plant of the poultry farm, consists of electrolysis, membrane filtration,
and ultraviolet disinfection as the main units. The general design purpose of the Izhevski PC treatment
plant is to treat about 1.25 m3
/h (51.72%) of the total wastewater generated from the defeathering
and cooling sections of the slaughterhouse to a recyclable degree. Water quality indices (WQIs) were
developed for each of the studied mixing ratios. A comparative analysis was also done with drinking
water quality standards set by the World Health Organization (WHO), as well as the government
of Kazakhstan. From the analysis results, the defeathering raw wastewater was generally higher
in pollution strength than the cooling wastewater. It was also observed that the increase in the
ratio of defeathering wastewater reduced treatment efficiency for some physicochemical parameters
such as turbidity, total suspended solids (TSS), color, biochemical oxygen demand (BOD), as well as
chemical oxygen demand (COD). However, 100% removal efficiency was achieved for the microbial
parameters for all the three studied ratios. Based on the computed WQIs, the highest-quality effluent
was achieved from the 20:80 (defeathering:cooling) mixing ratio. However, with the fact that all the
three mixing ratios produced “excellent” status, the 80:20 (defeathering:cooling) mixing ratio stands
to be an ideal option. The selection of 80:20 mixing ratio has the potential to reduce the pollution
load in the wastewater discharged to the sewerage system, while achieving high-quality effluent for
recycling in the cooling processes of the slaughterhouse.
