Fat Oil and Grease

Fat Oil and Grease

Fat, oil, and grease (FOG) typically enter wastewater from kitchens, food processing plants, and other organic waste sources. Once in sewers or treatment plants, FOG cools, solidifies, and causes persistent issues ranging from pipe blockages to operational inefficiencies 3.

Why It's a Problem

• Slowly biodegradable COD: FOG contributes a large fraction of slowly biodegradable COD (sbCOD), reducing microbial efficiency and disrupting typical treatment processes

• Pipe clogging and fatbergs: Accumulation can even lead to fatbergs—solid grease masses that clog sewers, disrupt flow, and dramatically increase maintenance costs

• Reduced biological activity: FOG forms a layer on the water surface or sludge, preventing effective oxygen and nutrient transfer and slowing microbial degradation

How FOG Promotes Filamentous Bacteria and Foam

Filamentous Overgrowth & Sludge Bulking

Filamentous bacteria such as Nocardia, Gordonia, and Microthrix parvicella thrive in high FOG environments. These organisms create stable threads and hydrophobic surfaces that trap gas and form persistent foam layers. This results in poor sludge settling, elevated sludge volume index (SVI), and frequent bulking issues

When filaments overgrow, sludge fails to settle properly in clarifiers, and effluent quality drops significantly due to carryover solids

Operational Impacts

• Foaming: Large foam mats interfere with surface skimmers and equipment, trap odours, and create safety hazards for workers

• Increased maintenance: Cleaning foam, desludging, and managing blocked pipes consumes resources and staff time.

• Treatment efficiency: FOG reduces biological degradation rates and increases total suspended solids (TSS), impacting effluent compliance and system performance

Micro‑Genix Solutions: Taming FOG and Filaments

Micro‑Genix offers a bioaugmentation solution specifically formulated to address FOG-related issues in activated sludge systems:

• Rapid FOG degradation using specialised lipase-producing microbes that break down fats into manageable forms

• Filament control by disrupting filamentous bacteria colonies, improving sludge flocculation and settling.

• Odour and foam management by eliminating sticky FOG layers and reducing filamentous foam build-up.

• Operational savings through reduced sludge hauling and less mechanical maintenance.

Benefits of Micro‑Genix FOG Treatment

The problem caused by FOG and Filaments results in bulking and poor settling. Treatment improves floc cohesion; reduces filament overgrowth, persistent foaming and clogs. Minimises foam-causing bacteria; unclogs operations, odour emissions and operational issues.

Real‑World Control of Filaments and FOG

Case studies show that bioaugmentation programs targeting filamentous bacteria significantly improve sludge settling. One municipal plant using “green” bioaugmentation achieved a doubling of reuse water capacity and resolved persistent Nocardia and foam issues widely attributed to high FOG influent. Conclusion: FOG = Fibres + Foam + Frustration

Uncontrolled FOG promotes filamentous bacteria, leading to bulking, foam, odour, and reduced treatment efficiency. Addressing it early with a targeted microbial solution like Micro‑Genix’s FOG Eliminator helps:

• Degrade persistent fats and oils

• Suppress foam-forming filaments

• Improve sludge settling and reduce TSS

• Lower odour and maintenance costs

Next Steps

For facilities facing sludge bulking, foam, or odour issues tied to FOG, Micro‑Genix offers tailored bioaugmentation treatments to restore system stability and compliance.

📧 info@micro-genix.com 📍 22 Success Street, Brisbane QLD 4000 🌐 www.micro-genix.com