Leather Tannery Wastewater Treatment & Water Reuse
Simplify High‑Salinity Effluent, Reduce Costs, and Achieve ZLD with VSEP®
Leather tanning is one of the world’s oldest industries—and one of the most challenging when it comes to industrial wastewater treatment. Modern tanneries face increasing pressure to control salinity, sulfides, chromium, BOD/COD, and water consumption while meeting stricter discharge limits and reducing operating costs add to the challenges facing leather tannery wastewater treatment.
VSEP® (Vibratory Shear Enhanced Process) membrane technology provides tannery operators with a simpler, more robust alternative to conventional multi‑stage treatment systems. VSEP has been shown to replace or enhance existing treatment, enabling water recycling, salt recovery, and zero liquid discharge (ZLD)—even for the most difficult tannery effluents.
Why Leather Tannery Wastewater Treatment Is So Difficult
Leather production requires water at nearly every step—as a carrier for chemicals, for hide cleaning, and to allow penetration of tanning agents into collagen fibers. That water is later removed by pressing and wringing, creating multiple wastewater streams that must be treated.
Typical water use in conventional tanneries ranges from 34–56 m³ (9,000–15,000 gallons) per ton of raw hides. Advanced facilities may reduce this by 60–80%, but only with complex treatment systems that are expensive to operate and maintain.
Leather tannery wastewater treatment is among the most complex industrial effluents, characterized by:
- Very high TDS and salinity (from brine curing and pickling)
- High BOD and COD (proteins, fats, oils)
- Sulfides and extreme pH swings
- Chromium (Cr³⁺) from chrome tanning
- Variable flow and shock loading
- EPA Guidelines 40 CFR Part 425
Design & Regulatory Context
- EPA Effluent Guidelines (40 CFR Part 425 – Leather Tanning & Finishing)
- Typical reuse targets aligned with ISO 14046 (Water Footprint)
- ZLD configurations consistent with global industrial reuse practices
Leather Tanning Processes That Generate Wastewater
- Hide Preservation (Salt Curing)
Salt curing preserves raw hides before processing. Salt draws moisture from the hide, creating a high‑salinity brine wastewater containing dirt, blood, manure, suspended solids, and moderate BOD/COD.
- Liming & Unhairing (Beamhouse Operations)
Lime and sodium sulfide remove hair and open collagen fibers. This step generates high‑pH, odorous wastewater rich in suspended solids, dissolved proteins, and toxic sulfides.
- Deliming, Bating & Pickling
Acids, enzymes, and salts neutralize lime and prepare hides for tanning. Effluent contains ammonia, nitrogen, sulfate, chloride, and residual organics.
- Chrome Tanning or Vegetable Tanning
- Chrome tanning uses chromium sulfate to stabilize collagen fibers.
- Vegetable tanning uses natural tannins from bark and wood (tannic acid).
Both processes generate wastewater with dissolved salts, organics, and (for chrome tanning) chromium.
- Post‑Tanning, Dyeing & Finishing
Finishing steps add dyes, synthetic tannins, oils, greases, and surfactants, producing colored, oily wastewater with elevated COD.
Typical Mixed Tannery Wastewater Characteristics
| Parameter | Typical Range |
| pH | 3 – 13 |
| COD | 3,000 – 15,000 mg/L |
| BOD₅ | 1,500 – 6,000 mg/L |
| TDS | 10,000 – 60,000 mg/L |
| Sulfide | 100 – 800 mg/L |
| Chromium (Cr³⁺) | 1 – 5 mg/L |
These characteristics explain why traditional treatment requires many separate unit operations and still struggles with reliability and cost.
Conventional Leather Tannery Wastewater Treatment: Complex and Costly
Every facility will have a unique treatment method, but for example, a typical treatment train may include:
- Screening, equalization, pH control
- Chemical coagulation and flocculation
- Sulfide oxidation
- Chromium precipitation and sludge handling
- Biological treatment (activated sludge, SBR, lagoons)
- Tertiary treatment (MBR, RO, evaporation, ZLD)
This approach is chemical‑intensive, labor‑intensive, and highly sensitive to salinity and shock loads.
There is a better way: VSEP.
A Smarter Approach: Segregate Brine, Simplify Treatment
The largest contributor to salinity is the brine preservation stream. By segregating this stream, overall treatment becomes dramatically easier.
| Parameter | Mixed Effluent. | Without Brine. | Brine Stream. |
| TDS (mg/L) | 10,000–60,000 | 3,000–8,000 | 7,000–52,000 |
| COD (mg/L) | 3,000–15,000 | 2,000–10,000 | 1,000–5,000 |
| BOD (mg/L) | 1,500–6,000 | 1,000–5,000 | 500–1,000 |
| Sulfide (mg/L) | 100–800 | 100–500 | 10–300 |
| Chromium (mg/L) | 1–5 | 1–5 | 0 |
Values shown are mg/L
This creates two manageable streams—each ideally suited for VSEP membrane filtration.
VSEP Solution for Brine Wastewater: Salt Recovery & Reuse
Salt is a major operating expense for tanneries. VSEP microfiltration (MF) systems can:
- Remove suspended solids, fats, oils, grease, proteins, and blood
- Produce clean salt water for reuse in hide preservation
- Reduce fresh salt purchases
- Reduce freshwater demand
Filtered brine can be recycled directly or dried using evaporation ponds or greenhouse evaporation barns, converting waste into a reusable resource.
VSEP MF Filtered Tanning Salt Brine (on the right)
VSEP Solution for Remaining Effluent: Water Recycling & ZLD
The remaining blended effluent (after brine removal) can be treated using VSEP reverse osmosis (RO).
With simple pretreatment (screening and pH adjustment to ~6.0–6.5), VSEP RO can:
- Reject BOD, COD, ammonia, sulfide, chromium, and chloride
- Reduce TDS by 90–95%
- Produce high‑quality recycled water for reuse in tanning operations
New Logic has pilot tested this scenario in the past. The small volume of RO concentrate can be further processed via thermal evaporation, enabling a full ZLD system.
Why VSEP Outperforms Conventional Membranes
Conventional spiral‑wound RO membranes foul rapidly on tannery wastewater. Spiral membranes require extensive pretreatment and cannot accept suspended solids and organics, exactly what makes tannery effluent difficult. MBR type membrane/bioreactor systems would struggle with salinity. VSEP is different. Key VSEP advantages:
- Wide membrane feed channels allow suspended solids to pass
- High‑frequency vibration (~50 Hz)
- Shear waves suppress fouling and scaling
- Stable, high flux at high solids and salinity
- Reduced cleaning frequency and downtime
VSEP has been successfully deployed in real tannery installations worldwide.
Economic & Operational Benefits for Tanneries
- Minimal chemical usage (except pH control)
- Reduced process complexity and labor
- Stable operation without biological upsets
- Smaller treatment footprint
- Lower salt and freshwater costs
- Practical path to water reuse and ZLD
VSEP Limitations and Design Considerations
- Recovery limited by osmotic pressure (TDS) and viscosity
- Performance will vary based on effluent composition
- Temperature affects throughput
- Prescreening is required to remove solids >100 µm
- VSEP cannot accept aromatic solvents and oxidizers
Design note: Actual performance is site‑specific. We pilot test to select membrane type, flux, recovery, and pretreatment options. Chemistry varies by tanning methods and plant configuration. Final system sizing, membrane selection, and performance projections are only provided after pilot validation.
The information here was prepared by an experienced New Logic engineer with more than 30 years of knowledge of industrial effluent treatment and membrane system design. This page has also been reviewed by New Logic’s CTO.
Proven Performance: Australian Tannery Case Studies
Case Study #1 – Brine Filtration & Salt Reuse
Operating continuously since 2004, New Logic installed an 84” VSEP microfiltration system in Australia for the treatment of the salt brine effluent processing 150 m3/day. The system removes fats, grease, suspended solids, proteins and blood from the brine effluent stream. The filtered salt brine is dried and reused.
A 0.05 micron Teflon membrane was used. The customer operates the unit at 70oC and runs at a feed pressure of 100 psi. The standard cleaning is flushing with warm caustic. A periodic cleaning with a chlorine solution for sanitation is also helpful to maintain the life of the filter pack. Performance has been predictable and stable to date. The system operates at about 95% recovery.
Case Study #2 – Rapid Payback Salt Recovery
In 2007 an 84” VSEP MF system was installed at another tannery in Australia. The system operates at 40ºC and about 85% recovery filtering the salt brine so it can be reused. This project built a solar evaporation system inside greenhouse buildings to amplify the heat from the sun. This customer was paying $1M per year for salt and the addition of the VSEP system paid for itself in a very short period.
Evaporation Barns used for VSEP Concentrate
Pilot Testing and Performance Projections
New Logic offers pilot testing—including full‑scale demonstrations to evaluate tannery water treatment performance. Performance projections are based on measured pilot data, not nameplate assumptions. Every project is unique, so pilot testing is needed.
Pilot testing allows:
- Verification of filtrate quality
- Measurement of flux, recovery, and fouling behavior
- Accurate operating cost projections
- Optimization for reuse or ZLD configurations
Request a No‑Cost Performance Projection
If you are evaluating ways to recycle water, manage discharge risk, or reduce costs — VSEP can help.
- Request a free VSEP performance projection for your tailings water:info@vsep.com
- View All Case Studies: https://www.vsep.com/case-studies/
- Detailed explanation of vibratory shear membrane operation:
https://www.vsep.com/technology/
Frequently Asked Questions (FAQ)
Can VSEP handle high‑salinity tannery wastewater?
Yes. VSEP has specifically demonstrated ability at full-scale for high‑TDS, high‑fouling industrial wastewater. Its vibratory shear prevents membrane scaling and fouling that typically shut down conventional RO systems in high‑salt tannery applications.
Does VSEP replace biological treatment?
In many cases, yes. By segregating the brine stream and using VSEP for physical separation, tanneries can reduce or eliminate reliance on biological systems that are sensitive to salinity, sulfides, and shock loads.
Can VSEP remove chromium from chrome tanning wastewater?
Yes. VSEP membranes effectively reject trivalent chromium (Cr³⁺) along with other dissolved solids. Chromium can be concentrated for controlled disposal or further processing, while clean water is recovered for reuse.
Is salt recovery really economical?
Yes. Many tanneries spend hundreds of thousands to millions of dollars per year on salt. VSEP microfiltration allows salt brine to be cleaned and reused, often delivering very short payback periods.
What level of water reuse is achievable?
Depending on feed quality and system design, VSEP systems have been shown to recover 70–95% of wastewater as reusable process water, significantly reducing freshwater intake and discharge volumes.
About VSEP and New Logic Research
- Located in Minden Nevada
- Over 38 years of membrane system design and manufacturing
- More than 450 industrial VSEP systems installed globally since 1987
- Technology covered by U.S. and international patents
- Used in mining, chemicals, food, wastewater, and chemical processing
- Engineering team with chemical, metallurgical, and mechanical engineering backgrounds
Last Webpage Technical Review: January 2026