Biodefoamer-Supported Activated Sludge System for the Treatment of Poultry Slaughterhouse Wastewater

Abstract

Poultry slaughterhouse wastewater (PSW) is laden with fats, oil, and grease (FOG), as well as proteins. As such, PSW promotes the proliferation of filamentous organisms, which cause foam formation. In this study, the production of biological defoamers (biodefoamers) uses a consortium with antagonistic properties, i.e., 1.39 L of wastewater/mL defoamers, as reported in our previous study, toward foam formers and their application in the treatment of PSW using a bench-scale activated sludge (AS)-supported treatment system consisting of an aeration and clarification tank. The foam produced was slimy, brown, and thick, suggesting the presence of Nocardia, Microthrix, and Type 1863 species in the PSW/AS wastewater treatment system. The bio (Bio-AS) and synthetic-defoamers (Syn-AS, positive control) supplementation, i.e., at 4% v/v in the PSW/AS primary treatment stage (aeration tank) operated over ten days, resulted in 94% and 98% FOG and protein removal for the biodefoamers, respectively, when compared to 50% and 92% for a synthetic defoamer, respectively. Similarly, the Bio-AS treatment achieved 85.4% COD removal, while a lowly 51% was observed for the Syn-AS PSW treatment regime. Overall, the biodefoamers performed vehemently compared to synthetic defoamers, improving the PSW/AS system’s performance. It was prudent to hypothesize that the biodefoamers might have had FOG solubilization attributes, an assertion that needs further research in future studies. It was concluded that Bio-AS was more efficient in the removal of FOG, proteins, TSS, and COD in comparison to Syn-AS and negative control without supplementation (CAS).

Keywords

• activated sludge
• chemical oxygen demand
• defoamers
• fats–oil–grease removal
• <i>Nocardia</i> spp.
• poultry slaughterhouse wastewater