Case Study: Successful Effluent Treatment Solutions

Objective:

Background

A mid-sized textile manufacturing company in India faced challenges in managing its wastewater:

• High Contaminant Load: Effluent contained dyes, heavy metals, and high Biological Oxygen Demand (BOD) levels.
• Non-Compliance: Repeated violations of Central Pollution Control Board (CPCB) discharge standards.
• High Disposal Costs: Dependence on external treatment facilities for final disposal.
• Environmental Concerns: Community complaints about groundwater contamination and ecosystem damage.

The company aimed to establish an in-house Effluent Treatment Plant (ETP) to achieve regulatory compliance, reduce costs, and align with sustainability goals.

Challenges

1. Complex Effluent Composition:
• Dyes, chemicals, and high salinity levels made treatment challenging.
2. Variable Effluent Flow:
• Fluctuations in wastewater volume based on production schedules.
3. Space Constraints:
• Limited area for setting up a full-scale ETP.
  

Solution: Implementation of an Advanced ETP

The company partnered with an engineering firm specializing in wastewater management to design and implement a customized ETP.

System Design and Processes

1. Pre-Treatment:

• Automatic Screens: Removed large particles like fibers and debris.
• Oil and Grease Trap: Eliminated floating oils and fats.
• Equalization Tank: Balanced effluent flow and pH levels.

1. Primary Treatment:

• Chemical Coagulation and Flocculation:
• Added alum and polyelectrolytes to aggregate fine particles and remove color.
• Sedimentation Tank:
• Settled out heavy solids to reduce Total Suspended Solids (TSS).

1. Secondary (Biological) Treatment:

• Moving Bed Biofilm Reactor (MBBR):
• Degraded organic matter (BOD/COD) using biofilms on plastic media.
• Aeration System:
• High-efficiency diffused aerators supplied oxygen for microbial activity.

1. Tertiary Treatment:

• Sand and Activated Carbon Filters:
• Removed residual particles and organic contaminants.
• Reverse Osmosis (RO):
• Reduced salinity and produced high-quality reusable water.
• UV Disinfection:
• Sterilized treated effluent for safe reuse or discharge.

1. Sludge Management:

• Centrifuge Dewatering:
• Reduced sludge volume for easier handling.
• Composting:
• Converted non-toxic sludge into agricultural fertilizer.

Results

1. Regulatory Compliance

• The treated effluent met all CPCB discharge standards:
• BOD: Reduced from 500 mg/L to <10 mg/L.
• TSS: Reduced from 600 mg/L to <20 mg/L.
• Color Removal: Achieved >95% removal of dye residues.

2. Cost Savings

• Eliminated reliance on external treatment facilities, saving ₹10 lakhs annually.
• Recycled 75% of treated water, reducing freshwater intake and costs.

3. Environmental Impact

• Prevented groundwater contamination by safely discharging high-quality effluent.
• Reduced environmental footprint by converting sludge into reusable fertilizer.

4. Community Benefits

• Improved relationships with local communities due to reduced environmental complaints.

5. Operational Efficiency

• Automated controls and IoT-based monitoring reduced manual intervention and ensured consistent system performance.

Key Success Factors

1. Customized Design:
• The ETP was tailored to handle the specific contaminants and flow variations of the textile plant.
2. Advanced Technologies:
• Use of MBBR, RO, and UV ensured high treatment efficiency.
3. Sustainability Focus:
• Water recovery and sludge reuse aligned with environmental goals.
4. Proactive Monitoring:
• IoT-enabled sensors provided real-time data on water quality, enabling quick corrective actions.

Conclusion

The successful implementation of the advanced ETP not only resolved the company’s compliance and operational challenges but also demonstrated a commitment to sustainability and corporate social responsibility. The project serves as a model for other industries facing similar effluent treatment challenges.