A wastewater treatment plant, or Effluent Treatment Plant is a system for purifying and recycling industrial wastewater. Its goal is to protect the ecosystem from the detrimental impacts of effluent by releasing safe water.
Depending on the industry, industrial effluents contain a wide range of materials. Food and beverage factories’ effluents contain biodegradable organic contaminants. Some effluents contain oils and grease, while others are poisonous. Because of the variety of toxins found in industrial wastewater, specialized treatment techniques known as ETP are necessary.
diverse physical, chemical, biological, and membrane processes are utilized in an ETP Plant to treat wastewater from diverse industrial sectors such as chemicals, medications, pharmaceuticals, refineries, dairy, ready mix industries, and textiles.
Types of Effluent Treatment Plants
There are various types of ETPs available, each designed to cater to specific industries and their unique effluent characteristics.
1. Physical Treatment Systems:
These systems primarily rely on physical processes such as sedimentation, filtration, and flotation to remove solid particles from the wastewater.
2. Chemical Treatment Systems:
Chemical treatment systems use chemicals like coagulants and flocculants to facilitate the separation of suspended solids from water through precipitation or chemical reactions.
3. Biological Treatment Systems:
Biological treatment systems utilize microorganisms that break down organic matter present in the wastewater through natural biological processes like aerobic or anaerobic digestion.
4. Advanced Treatment Systems:
Advanced treatment systems combine multiple processes such as physical, chemical, and biological methods for more efficient removal of pollutants, including dissolved contaminants like heavy metals or toxins.
5. Modular/Containerized ETPs:
These prefabricated ETP units are designed for easy installation and transportation, making them suitable for temporary projects or locations with limited space availability.
6. Zero Liquid Discharge (ZLD) Plants:
ZLD plants aim at eliminating liquid discharge by recycling treated water back into industrial processes or evaporating it to achieve zero liquid waste generation.
By using effluent treatment plants (ETPs), large quantities of organic compounds, debris, dirt, grit, pollution, poisonous, toxic molecules, and polymers are removed from industrial effluent.
Stages of Effluent Treatment in ETPs
- The Screen Chamber eliminates large solids to prevent abrasion of mechanical equipment and blockage of hydraulic systems.
- Tanks for Collection The effluent from the screening chamber is collected, stored, and pumped to equalization tanks.
- The Equalization Tank Adjustments to the effluent’s concentration and pH will occasionally occur. An equalization tank holds the effluents for 8 to 12 hours, allowing uniform mixing and neutralization.
- Coagulants are added to the effluents: 800-1000 ppm lime. To remove color and elevate the pH to 8 or 9 (200-300 ppm), use alum. Polyelectrolyte: Used to settle suspended materials and reduce SS and TSS (0.2 ppm). When these chemicals are applied and immediately and thoroughly combined, the flocculates can unite uniformly to produce micro-flocs.
- In a clariflocculator, a stirrer constantly stirs the water inside. By flocculating, which offers slow mixing, macro flocs settle in the clarifier zone, facilitating the formation of macro flocs. The overflow water enters the aeration tank. As the solid particles separate, settle, and are collected separately, SS and TSS decrease. The settled solids are then pumped into drying beds for primary sludge.
- During aerobic treatment, the effluent is sent to an aeration tank after clearing. In this tank, air is passed through air blowers or diffusers. A high level of dissolved oxygen (DO) must be maintained to allow bacteria to flourish and remove BOD and COD by decomposing the debris. In the effluent, BOD and COD readings are 90% less.
- The overflow from the aeration tank is received by the secondary clarifier, where solid liquid separation occurs. To maintain the required MLSS level in the secondary clarifier, part of the biological sludge is recycled back into the aeration tank, and the remaining sludge is collected.
- It is possible to separate the solids from the liquids using centrifugal force in a sludge thickener. The inflow sludge consists of 40% solids and 60% water. The effluent’s water content is reduced by the sludge thickener to 40% water + 60% solids. Once the wastewater has been treated, the sludge is collected at the bottom of the tank.
- Drying beds reduce the water content of primary and secondary sludge by drying them.
Choosing the right effluent treatment plant (ETP) is crucial for any industry or establishment that generates wastewater. With various types of ETPs available, it’s important to understand your specific requirements and consider the pros and cons before deciding. By assessing factors such as the type and volume of wastewater being generated, you can determine the ideal size of ETP needed for your facility. Additionally, regular maintenance and monitoring are essential to ensure optimal performance and longevity of your ETP.
Kelvin Water Technologies Pvt. Ltd. is a leading provider of wastewater treatment systems in India. We are dedicated to offering superior effluent treatment systems and plants, tailored to the individual needs of our industrial clients. Our commitment has earned us a great reputation for providing outstanding services and solutions that can help reduce operating costs and lengthen the lifespan of their equipment. Not only do we provide free installation with each system purchased, but we also include a manufacturer’s warranty and 24-hour customer service after purchase.