CETP for Tannery & Leather Clusters
Common Effluent Treatment Plants for tannery clusters — chrome recovery, sulphide destruction, biological treatment, and ZLD compliance for Jalandhar, Kanpur, Vellore, and other leather processing clusters
Industry Overview
CETP for Tannery & Leather Clusters
India's tannery industry is concentrated in a handful of major clusters — Kanpur and Agra in Uttar Pradesh, Jalandhar in Punjab, Vellore and Ranipet in Tamil Nadu, and Kolkata's Tangra zone — each generating large volumes of complex, hazardous-classified effluent containing chromium, sulphide, high BOD from hide proteins, and very high TDS from salt curing. The NGT has issued specific directions for every major tannery cluster requiring Zero Liquid Discharge-level CETPs, and the CPCB has classified tanneries as Red Category industries. Spans Envirotech has direct CETP experience in the tannery sector, including the Jalandhar tannery and leather complex CETP. Learn more about our CETP capabilities and our ZLD for tannery and leather industry approach.
Tannery CETP design is fundamentally different from textile or chemical CETPs because of two mandatory pre-treatment steps that must occur before the combined effluent enters the biological stage: chrome recovery and sulphide destruction. Chrome-bearing spent liquor from tanning drums must be collected in segregated channels at each member unit and either treated for chrome recovery on-site or conveyed separately to the CETP's dedicated chrome recovery unit — preventing chrome from entering and toxifying the biological treatment. Separately, beam house sulphide-bearing wastewater must undergo aeration at high pH to destroy sulphide before combining with the main effluent stream. Only after these two steps can the combined tannery cluster effluent proceed to biological treatment. Our MBBR for tannery wastewater page covers the biological treatment stage in detail.
Spans Envirotech designs tannery CETPs as integrated systems — chrome recovery unit, sulphide destruction, equalisation, MBBR biological treatment, secondary clarification, and where mandated, UF + RO + MEE for ZLD. Our tannery CETP designs incorporate the hazardous sludge management plan (TSDF disposal of chrome cake and biological sludge), SPCB-compliant OCEMS for online chrome, sulphide, and COD monitoring, and SPV operational training enabling the CETP management team to run the facility compliantly with minimal external engineering support.
Industry Challenges
Key Environmental Challenges
Chrome Recovery as Non-Negotiable Pre-Step
Spent chrome liquor from all chrome-tanning member units must be collected separately and chrome-recovered before any biological treatment can function; system design, piping, and member unit compliance for chrome segregation must be built into the CETP project from day one.
Sulphide H₂S Safety Risk
Sulphide in beam house wastewater creates H₂S toxicity risk in the collection network; alkaline operating conditions must be maintained throughout the sewer to prevent H₂S evolution; sulphide detection in the CETP inlet sump is a safety-critical monitoring requirement.
Very High TDS Limiting RO Recovery
Tannery effluent TDS after biological treatment reaches 8,000–25,000 mg/L from salt-curing and tanning chemicals; two-pass RO is required for ZLD, with conservative recovery rates (55–70%) due to the high osmotic pressure.
Hazardous Waste Classification and TSDF Obligation
Chrome sludge, biological sludge, and MEE salt cake may be hazardous-classified; TSDF disposal adds to operating cost and requires manifesting, transport permits, and SPCB-approved disposal documentation — all managed by the CETP SPV.
Member Unit Compliance for Chrome Segregation
The CETP's entire biological treatment depends on member units segregating chrome-bearing liquor before discharge; non-compliant discharge of chrome-mixed general effluent is the most common cause of tannery CETP biological treatment failure.
Our Solutions
Tailored Wastewater Treatment Solutions
Centralised Chrome Recovery Unit
Dedicated chrome liquor reception tank, alkali precipitation with NaOH, chrome cake filtration and acidification with H₂SO₄ for chrome liquor reconstitution; chrome cake sold to member units as recovered basic chrome sulphate — partially offsetting CETP operating cost.
Sulphide Destruction with H₂S Monitoring
Beam house stream collection in separate alkaline channel; aeration at pH >9.5 in dedicated sulphide destruction tank; online H₂S monitoring at inlet sump and destruction tank; alarm and shutdown protocols for worker safety.
MBBR Biological Treatment for Mixed Tannery Effluent
MBBR sized for combined cluster flow after chrome recovery and sulphide destruction; nutrient dosing (urea/DAP) required given the nitrogen-deficient character of hide-protein organics; robust carrier media loading for high organic loads.
ZLD Train — UF + RO + MEE
UF pre-treatment protecting RO membranes from residual TSS and colloidal chrome; two-pass high-pressure RO for high-TDS tannery concentrate; MEE evaporation producing salt cake; all compliant with TSDF disposal or industrial reuse.
SPCB-Compliant OCEMS with Chrome and Sulphide Monitoring
Online continuous effluent monitoring for total chromium, sulphide, BOD proxy (COD or UV-vis), flow, and pH — meeting CPCB OCEMS requirements for Red Category CETP facilities; data connected to SPCB server.
Technologies
Proven Technologies for Your Industry
Benefits
Why Choose Spans for Your Industry
- NGT cluster-specific orders and CPCB ZLD mandate compliance for tannery clusters
- Chrome recovery unit recovers Cr₂(SO₄)₃ for resale to member units — reducing CETP operating cost
- H₂S sulphide safety risk eliminated through dedicated destruction and online monitoring
- MBBR biological treatment tolerates high organic load from hide-protein tannery effluent
- TSDF-compliant hazardous sludge management plan integrated into CETP project scope
- OCEMS with chrome and sulphide monitoring meets CPCB Red Category real-time monitoring mandate
Ready to Transform Your CETP for Tannery & Leather Clusters Operations?
Let our experts design a custom solution for your facility.