ETP for Seafood Processing
DAF and MBBR-based effluent treatment plants for fish processing, shrimp export units, canning facilities, and seafood cold chains — managing extreme organic loads, blood water, fish oil, and ammoniacal nitrogen to achieve CPCB discharge compliance
Industry Overview
ETP for Seafood Processing
India is one of the world's largest seafood exporters, with over 2,000 seafood processing units concentrated in Gujarat, Kerala, Andhra Pradesh, Tamil Nadu, Odisha, and West Bengal. Seafood processing generates highly polluted wastewater from washing, gutting, filleting, brining, and cooking operations. This wastewater is characterised by BOD 600–2,500 mg/L, COD 1,000–4,500 mg/L, TSS 300–1,200 mg/L, FOG 200–600 mg/L, and ammonia-nitrogen 50–200 mg/L from protein breakdown. Seasonal variability is extreme — shrimp trawl seasons and export order peaks create 5–10× flow fluctuations within weeks.
The food safety implications of seafood ETP performance are direct: MPEDA (Marine Products Export Development Authority), EIA (export certification bodies), and HACCP/BRC auditors all assess ETP compliance as part of export unit certification. A non-compliant ETP or a SPCB enforcement notice can trigger export license suspension — a severe commercial consequence. European and US seafood buyers are increasingly requiring third-party wastewater treatment audits from Indian suppliers.
Spans Envirotech designs and delivers ETP systems for seafood processing plants from 50 KLD to 2 MLD, combining DAF primary treatment (for FOG and suspended solids removal), MBBR biological treatment (for BOD/COD/ammonia), and UV disinfection. Our systems are designed for the odour control requirements of coastal processing zones and for compliance with CPCB General Standards as well as state-level coastal zone regulations. Biogas recovery from anaerobic pre-treatment is economically attractive for large facilities.
Industry Challenges
Key Environmental Challenges
Extreme Organic Load and FOG
Seafood wastewater BOD 600–2,500 mg/L with heavy fish oil (FOG 200–600 mg/L) requires effective primary DAF treatment before biological stage. Unmanaged FOG fouls MBBR carriers and activated sludge systems rapidly. Processing different species (fish vs shrimp vs cephalopods) produces different FOG compositions requiring adaptable coagulant dosing.
High Ammoniacal Nitrogen from Protein Degradation
Seafood proteins break down rapidly to ammonia at processing temperatures. Inlet ammonia-N of 50–200 mg/L requires a nitrifying biological system — MBBR systems with adequate HRT (6–12 hours at DO 3–4 mg/L) for nitrification. CPCB specifies ammonia-N <50 mg/L for discharge to surface water.
Extreme Seasonal Flow Variability
Shrimp and fish trawl seasons create 5–10× flow peaks lasting weeks. ETP design must accommodate peak flows without biological system failure. Equalization tanks sized for 8–12 hours HRT are essential, combined with modular MBBR capacity that can handle variable loads.
Odour Management in Coastal Processing Zones
Hydrogen sulphide and putrescine/cadaverine from protein decomposition create severe odour problems in seafood ETPs. Collection systems, equalization tanks, and biological stage must be covered with biofilter or chemical scrubber odour treatment. Many seafood processing zones are near residential areas where odour complaints lead to SPCB closure orders.
High Salinity from Brining Operations
Shrimp and fish brining generates high-salinity wastewater (TDS 5,000–30,000 mg/L) that inhibits biological treatment microorganisms adapted to fresh-water conditions. ETP design must account for salt-tolerant biofilm development or pre-dilution strategies.
Our Solutions
Tailored Wastewater Treatment Solutions
DAF Primary Treatment for Fish Oil Removal
Dissolved Air Flotation with PAC or ferric coagulant (dose 100–400 mg/L) removes 85–95% of FOG and 40–55% of COD before biological treatment. Air-to-solids ratio of 0.05–0.1 is critical for fish-oil flotation. Rendered float (fish oil sludge) can be processed as a byproduct.
MBBR for BOD and Ammonia Treatment
MBBR systems (media fill 40–55%) achieve BOD <30 mg/L and ammonia-N <15 mg/L from seafood wastewater at HRT of 8–16 hours. Two-stage MBBR (aerobic BOD removal + nitrification) provides stable performance across seasonal load variability.
Equalization and Covered Tankage for Odour Control
Covered equalization tanks (8–12 hours HRT) with submersible mixers buffer flow variability. Biogas from septic inlet wastewater is captured and treated in a chemical scrubber or biofilter (hydrogen peroxide or sodium hypochlorite dosing) before release. SCADA monitors H₂S continuously.
Biogas Recovery from Anaerobic Pre-Treatment
For plants >200 KLD, UASB pre-treatment before MBBR reduces COD 60–70% and generates biogas (0.4–0.5 m³/kg COD removed) for thermal use in fish meal drying or cold storage energy supply — saving ₹20–60 Lakh/year in LPG or electricity costs.
CPCB/MPEDA Compliance Documentation System
SCADA-based real-time monitoring with automated daily reports, lab data integration, and export-ready compliance certificates for MPEDA audits. Treated water parameters logged continuously for SPCB Form V submissions.
Technologies
Proven Technologies for Your Industry
Benefits
Why Choose Spans for Your Industry
- CPCB and MPEDA compliance — protecting export licenses and EU/US buyer certifications
- Fish oil recovery from DAF float as byproduct — ₹5–15 Lakh/year for medium plants
- Biogas recovery reduces LPG or electricity costs by ₹20–60 Lakh/year for large facilities
- Odour control system prevents residential complaints and SPCB closure notices
- Handles 10× seasonal flow variability without biological system failure
- SCADA-based compliance reporting ready for MPEDA and BRC/HACCP audits
Success Stories
Case Studies
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