Effluent Treatment Plant of Edison Footwear Ltd. #etp

An effluent treatment plant (ETP) for the footwear industry is designed to treat wastewater generated during various stages of production, which may include leather tanning, adhesives, chemicals, and dyes. This wastewater often contains organic matter, heavy metals, chromium, chemicals, and other hazardous materials.

### Key Stages in ETP for Footwear Industry

1. **Preliminary Treatment**:
- **Screening**: Removes large solids such as leather pieces, plastics, and other debris from the effluent.
- **Oil and Grease Removal**: Skimming tanks are used to remove oils, greases, and other floating materials.
- **Equalization**: Balances the pH and flow rate of the wastewater, preventing large surges and maintaining a steady flow into subsequent stages.

2. **Primary Treatment**:
- **Coagulation and Flocculation**: Chemicals like alum or ferric chloride are added to neutralize charged particles, allowing them to form larger aggregates (flocs).
- **Sedimentation**: The flocs are settled at the bottom of the tank and removed as sludge.

3. **Secondary Treatment**:
- **Biological Treatment**: This involves the use of aerobic or anaerobic microorganisms to break down organic matter in the effluent. Aeration tanks or activated sludge processes are common.
- **Trickling Filters or Biofilters**: Another biological process that further reduces organic content using microbial films on a bed of materials like gravel or plastic.

4. **Tertiary Treatment**:
- **Filtration**: Advanced filtration systems, such as sand filters, activated carbon filters, or membrane technologies, remove remaining suspended particles and organic matter.
- **Disinfection**: Chlorination, UV radiation, or ozone is used to kill pathogens before the treated water is discharged or reused.
- **Heavy Metal Removal**: Specialized treatments are used to remove chromium, lead, or other heavy metals, especially if the effluent is from a leather tanning unit within the footwear industry.

5. **Sludge Handling**:
- **Dewatering**: Sludge generated from sedimentation is treated in a dewatering unit to reduce moisture and prepare it for safe disposal.
- **Sludge Disposal**: The dried sludge may either be disposed of in landfills or, in some cases, incinerated if it contains hazardous materials.

### Challenges
- **Chromium Management**: Particularly in tanneries, chromium removal is critical, as it is a toxic heavy metal.
- **Chemical Handling**: Managing chemicals like adhesives and dyes requires careful treatment to prevent environmental contamination.
- **Water Reuse**: Some plants focus on treating water to a quality where it can be reused within the production process, reducing overall water consumption.

An efficient ETP can help the footwear industry meet environmental regulations, avoid penalties, and contribute to sustainable production.