TaxTMI 
TaxTMI 
TaxTMI 
Zero Liquid Discharge (ZLD) roadmap tailored for the Textile Industry.
Heres a custom Zero Liquid Discharge (ZLD) roadmap tailored for the Textile Industry, particularly relevant for dyeing and finishing units — sectors known for generating large volumes of high-strength effluent with complex pollutants like color, high COD, and TDS.
?? ZLD Roadmap for the Textile Industry
?? Focus: Dyeing, printing, washing, and finishing units
?? Effluent Profile of Textile Units
Parameter | Typical Range | Notes |
pH | 9–11 | Alkaline due to chemicals |
COD | 1500–5000 mg/L | High from dyes, sizing agents |
BOD | 500–1500 mg/L | Organic content from starch, oils |
TDS | 5000–15000+ mg/L | From salts, soda ash, softeners |
Color | Very High | Reactive, direct dyes hard to remove |
Suspended Solids | Moderate | Lint, fibers, silt |
?? Custom ZLD Roadmap for Textile Manufacturing
1. Source Reduction and Process Optimization
- Use low-liquor ratio machines
- Replace high TDS chemicals with eco-friendly ones (e.g., enzymatic desizing)
- Optimize batch operations to reduce rinse cycles and water use
?? Every 1 m³ of water saved reduces 1 m³ of wastewater to treat.
2. Segregate Wastewater Streams
Stream Type | Source | Treatment Strategy |
Low TDS, High Color | Dyeing, washing | Treat with AOP + RO |
High TDS, Low COD | Softening, salt baths | Direct to MEE |
Miscellaneous | Machine cleaning, floor wash | Biological + tertiary treatment |
3. Primary Treatment
- Screening & Grit Removal – Remove lint, fibers, suspended solids
- Equalization Tank – Buffer flow & load variation
- Neutralization – pH correction
4. Advanced Oxidation for Color Removal
- Fenton’s Reagent, Ozonation or UV/H2O2
- Breaks dye molecules resistant to biodegradation
- Improves performance of RO membranes downstream
5. Biological Treatment
- SBR (Sequential Batch Reactor) or MBR (Membrane Bioreactor)
- MBR preferred due to compactness and higher effluent quality
- Reduces COD/BOD to meet tertiary treatment standards
6. Tertiary Treatment – RO System
- Multi-stage Reverse Osmosis
- Recovers 70–85% of water
- Permeate reused in dyeing/washing operations
- RO reject (high TDS) sent to evaporator
7. Evaporation and Crystallization
- Multiple Effect Evaporator (MEE)
- Uses steam to evaporate water from RO reject
- Condensate is reused
- Crystallizer (optional)
- Converts concentrated brine into solid salt cake
8. Reuse & Recycling
Reused Water | Application |
RO Permeate | Dyeing machines, rinsing, utility water |
MEE Condensate | Boiler feed, cooling towers |
Sludge Dewatered Cake | Landfill or co-processing (if non-hazardous) |
?? Recommended Technology Flow (Textile ZLD)
Wastewater
?
Equalization Tank
?
pH Neutralization
?
Advanced Oxidation (Fenton/UV-Ozone)
?
Biological Treatment (MBR/SBR)
?
Filtration + Reverse Osmosis
? ?
RO Permeate ? Reuse RO Reject
?
Multiple Effect Evaporator (MEE)
?
Condensate ? Reuse | Salts ? Disposal
?? Compliance Requirements (India Example)
- Tamil Nadu, Gujarat, Maharashtra, and other states have made ZLD mandatory for textile dyeing clusters
- Must submit:
- Water balance report
- ZLD system commissioning certificate
- Online monitoring (OCEMS) data to CPCB/SPCB
- Reuse = 90% of water; no discharge outside premises
?? Cost & Sustainability Factors
Item | Impact |
CAPEX | ?1–5 crore (depends on capacity, tech level) |
OPEX | Energy, chemicals for MEE and RO |
ROI | 3–5 years via water reuse, compliance cost savings |
Carbon Footprint | Can be mitigated using solar steam or waste heat recovery for MEE |
? Compliance & Sustainability Checklist
Action | Status |
Water audit completed | ? / ? |
Effluent segregation done | ? / ? |
AOP system installed | ? / ? |
Biological ETP working | ? / ? |
Tertiary + RO system in place | ? / ? |
MEE commissioned | ? / ? |
Condensate reused | ? / ? |
Solids disposed as per norms | ? / ? |
Online monitoring system active | ? / ? |
????? Best Practices from Model Textile Clusters
- Perundurai (TN), Surat (GJ), Ludhiana (PB) have successful CETPs with ZLD
- CETP + ZLD model for MSMEs is efficient and cost-effective
- Consortium-based systems reduce individual costs and ensure regulatory compliance
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