Investigation of treatability of wastewater from slaughterhouses

Slaughterhouse wastewaters containing high chemical oxygen demand (COD) (3 500 – 12 500 mg/L), biological oxygen demand (BOD) (1 250- 1 900 mg/L), total suspended solids (TSS) (400 – 2 300 mg/L), total phosphorus (TP) (2 – 7,5 mg/L), total nitrogen (TN) (25 – 32 mg/L), oil&grease (90 – 2 700 mg/L) and blood have occured during and after the cutting in slaughterhouse. Since the twenty and five days BOD values of blood are 405 000 mg/L and 150 000 - 200 000 mg/L, respectively, the slaughterhouse wastewater containing high amounts of blood needs to be treated before discharging to the receiving media. Physical, chemical and biological methods are used in the treatment of this kind of wastewaters which are difficult and costly to be treated due to the high amounts of pollutants. In this study, the characterization of wastewater from a slaughterhouse with 70 ovines and 230 bovines in Konya was determined and their treatability was investigated. In this way, a wastewater treatment system including physicochemical and biological treatment units was dimensioned and necessary cost calculation was made for the etablishment of this treatment system. As a result of treatment with physicochemical and biological treatment systems; COD, oil&grease and colour removal efficiencies were determined as 98%, 98% and 90%, respectively. With this removal efficiencies COD was reduced to 78,4 mg/L, oil&grease to 10 mg/L, color to 78,5 mg/L. It has been concluded that physicochemical and biological processes are suitable treatment methods for slaughterhouse wastewater treatment.