Anaerobic/aerobic treatment of meat processing wastewater

The meat processing industry is believed to produce highly polluted wastewater. Analysis of such wastewater indicated that the waste was highly contaminated with organic compounds as indicated by COD (1544 mgO2 l-1), BOD (646 mgO2 l-1), and TSS (1155 mg l-1). Moreover, oil and grease concentrations reached 144 mg l-1 treatment of raw wastewater using Upflow Anaerobic Sludge Blanket (UASB) followed by Rotating Biological Contactors (RBC) was studied. Efficiency of the UASB for the removal of COD(total), BOD(total), TSS, and oil and grease was 56%, 56%, 85%, and 58%, respectively. The quality of the UASB effluent barely complies with the regulatory standards for discharging wastewater into the sewerage network. UASB effluent was subjected for further treatment using a RBC unit to improve the quality of the treated effluent for reuse in irrigation purposes. Residual COD, BOD, TSS, and oil and grease, following RBC, was 132 mgO2 l-1, 40 mgO2 l-1, 44 mg l-1, and 10 mg l-1 respectively. The overall efficiency of the treatment units provided good quality effluent. The overall percentage removal of COD, BOD, TSS, and oil and grease was 91.5%, 94%, 96%, and 91%, respectively. Based on the quality of the treated effluent and guidelines recommended for wastewater reuse, it may be concluded that a slight to moderate restricted irrigation is applicable to reuse the treated effluent in the green belt around the factory. Disinfection should be applied to ensure the safety of such a process.