Food wastewater is inherently biologically degradable with high organic load. This is both an advantage (biology works well) and a risk (uncontrolled release causes odor, flies and anaerobic breakdown).
Typical parameters: COD 1,500-8,000 mg/L, BOD 800-4,000 mg/L, FOG 200-1,500 mg/L, total N 80-400 mg/L. Seasonal swings (canning season, summer ice cream peak) and diurnal flow are pronounced.
Hence food plant WWTP is designed as wide equalization + DAF/grease trap + anaerobic (UASB/EGSB) + aerobic (MBBR/AS) + tertiary. Anaerobic biogas can largely cover plant electricity and heat demand.
Food Plant Wastewater Profile
Food spans a wide range: canneries see seasonal peaks, frozen food plants generate constant wash water, bakeries carry high sugar and gluten, ready-meal plants discharge fat-and-protein-heavy effluent.
Common features: high BOD/COD, biodegradability (BOD/COD > 0.5), alkaline shocks during CIP, FOG load. An effective food WWTP must remain flexible under these swings.
Carbohydrate-rich effluents (sugar, starch) ferment quickly and cause odor even in storage. Equalization tanks must be covered and aerated.
Anaerobic + Aerobic Hybrid
The anaerobic stage handles the high load without oxygen and produces biogas:
- Pre-settling + equalization
- pH neutralization
- DAF or grease trap (FOG < 50 mg/L)
- UASB or EGSB reactor (80% COD removal, biogas output)
- Aerobic MBBR or AS (residual COD + nitrification)
- Final clarifier
- Sand filter + UV
Biogas Recovery Details
UASB biogas is 60-70% methane. A typical 5,000 m³/day food plant yields:
- ~1,500-2,500 m³/day biogas
- Equivalent 8,000-12,000 kWh/day energy
- Cogeneration unit for power + heat
- Covers nearly 100% of boiler heat demand
- 3-5 year payback
Food Sector Regulation & Halal Compliance
Food wastewater is governed by SKKY Tables 5 and 5.1. Discharge limits: COD < 160 mg/L, BOD < 50 mg/L, TSS < 100 mg/L, FOG < 20 mg/L. Halal-certified plants must use halal-compliant treatment chemicals.
Anaerobic biogas plants under 5 MW are exempt from the EPDK production license. Generated electricity can be self-consumed or sold to YEKDEM, and earns carbon footprint reduction credits.
Under HACCP/ISO 22000, the WWTP must be away from process water lines and hygiene rules apply to operators.
Food WWTP Advantages
Food Sector References
WWTP references at canning, frozen food, bakery and ready-meal plants.
Frequently Asked Questions
UASB granule formation takes 2-4 months with seed sludge. Full capacity is reached in 4-6 months. Once granules form they remain stable for years.
Concentrated caustic/acid CIP residues kill bacteria if fed directly. A separate CIP tank + controlled dosing is used — CIP batches are bled in over 24-48 hours.
No. Run at low load — biology enters endogenous metabolism with aeration and mixing only. Return to full capacity in 1-2 weeks.
DAF removes 99% of FOG — even 1,500 mg/L inlet drops below 20 mg/L. Recovered fat can be co-fed to the biogas digester.
Standard coagulants (FeCl3, alum) and polymers are halal-compliant. Only ethanol-based chemicals (some antifoam) are excluded — halal alternatives exist.
Yes — separate dairy and fruit juice sector pages exist. Sub-sectors like canning, bakery, confectionery and frozen food are covered on this general page.