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Poultry slaughterhouse wastewater (PSW) with a high fats, oil, and grease (FOG) content in South Africa (SA) is generally discharged into municipal wastewater systems. This is detrimental for municipal treatment plants since there is a limited number of these wastewater treatment works (WWTWs) that are operating optimally. Furthermore, increasingly stringent standards for effluent discharge have placed an urgency on the development of advanced wastewater treatment technologies. This study evaluated the performance of a lab-scale integrated multi-stage PSW treatment system consisting of an aerobic pre-treatment tank, an expanded granular sludge bed (EGSB) bioreactor coupled with a submerged ultrafiltration (UF) membrane. The possibility of treating PSW to a water quality standard compliant with discharge by-laws or the standards of effluent discharge was investigated. The EGSB was operated for 120 days at a hydraulic retention time (HRT) of 5.71 h and an organic loading rate (OLR) ranging from 200 to 700 mg COD/L·h, while the submerged membrane unit had OLR fluctuating between 50 and 450 mg COD/L·h. The integrated system achieved overall average removal efficiencies (REs) of 98% for chemical oxygen demand (COD), 97% for FOG, and 99% for total suspended solids (TSS); and reducing the pollutant content of the treated PSW to 101 mg/L COD, 8 mg/L FOG and 7 mg/L TSS, i.e. qualities which are comparable to inland surface water, rendering it safe for discharge into the City of Cape Town (CCT) WWTWs.

This study evaluated the performance of a lab-scale poultry slaughterhouse wastewater (PSW) treatment system consisting of a static granular bed reactor (SGBR) coupled with single stage nitrification-denitrification (SND) bioreactor and ultrafiltration membrane module (ufMM) systems. The feasibility of treating PSW to a water quality standard compliant with industrial wastewater discharge standards was investigated. The SGBR was operated at hydraulic retention times (HRTs) ranging from 24 to 96 h and organic loading rates (OLRs) ranging from 0.73 to 12.49 g COD/L.day, for 138 days. The chemical oxygen demand (COD), total suspended solids (TSS), biological oxygen demand (BOD5) and fats, oils and grease (FOG) removal efficiencies achieved by the SGBR averaged 80%, 95%, 89% and 80%, respectively. The SND bioreactor achieved total nitrogen (TN) removal efficiencies of 33% and 79% for the SGBR effluent, when operated in down-flow mode without aeration and up-flow mode with aeration, respectively. The ufMMs, operated in dead-end filtration mode, were able to further reduce the COD and TSS by an average of 65% and 54%, respectively. The results for the PSW treatment system demonstrated the combined benefits of biological and physical treatment processes, with averaged COD, ortho-phosphate (PO43−-P), TSS and total dissolved solids (TDS) removal efficiencies of 91%, 51%, 97% and 52%, respectively, being achieved over 52 days. The final effluent was deemed suitable for discharge; although, the PO43- and NH4+-N requires further monitoring and the PSW treatment system design requires refinement.