In this article, we are going to learn about the ETP process followed in textile industries. What is ETP, how water is polluted in textiles, why it is needed in textile industries, and how the process is done. So without further delay, let's start from here.
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What is ETP?
The term "Effluent Treatment Plant," or ETP, refers to a system created to treat and manage industrial wastewater, or effluent, produced by numerous industries, including the textile industry. To ensure that the discharged water complies with environmental requirements and standards before it is released into the environment, an ETP is used in the context of the textile industry to treat and purify the wastewater produced during production operations.
What Makes Wastewater in Textile?
In the textile industry, mostly in the dyeing and printing section, NaOH and acid are mostly used with different coloring agents. These chemicals should not be thrown away or drained into natural sources because all living organisms like fish can die from the effect of too much acid or too much alkali and coloring agents.
Process Flowchart of ETP
Screening
↓
Primary Treatment (Inlet Effluent Plant, Lifting Tank, Cooling Tank)
↓
Secondary Treatment (Anoxic/Anaerobic/Aerated Storage Tank)
↓
Tertiary Treatment (Neutralization Tank, Oxidation Tank, Clarifier Feeding Tank, Clarifier, Oxygen Increase Tank)
↓
Disinfection (Microfiltration)
↓
Sludge Recycle Tank (Sludge Recycle Tank, Sludge Thickener)
↓
Discharging Tank
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| ETP Processes © Textile Pad |
Description of the Processes of ETP
To clean and purify the wastewater, an ETP in the textile sector typically comprises many stages or processes. These stages could involve:
Screening
Screening is the first of the first labels of ETP. Screening is the extraction from wastewater of large solids, trash, and suspended particles. Only chemicals with water pass through the screening process.
Primary Treatment
Physical processes such as sedimentation and flotation are used as the primary treatment to remove sludge and suspended materials from wastewater.
Inlet Effluent Plant
Here, water coming after screening is stored first.
Lifting Tank
The tank is literally in a lower position to collect the sediments. A motor is used to lift the water to the cooling tank.
Cooling Tank
In this tank, water is lifted by a motor. The water becomes hot here for using steam and there is a big fan at the upper side of this tank. Here, hot water becomes cool. This cold water is then passed on to the next process.
Secondary Process
Biological procedures used in secondary treatment involve the breakdown of organic contaminants in wastewater by microorganisms. Techniques for treating this could be aerobic or anaerobic.
Anoxic Storage Tank
This is the storage of water by anoxic bacteria. There is a limit marked for this tank. When the water gets higher in volume and crosses the limit the above water is being ready to move to the next process.
Anaerobic Storage Tank
This storage is the same as an anoxic tank, the difference is here the bacteria used- is anaerobic. The limit is also marked in this tank and crossing it puts the water to the next process.
Aerated Storage Tank
This tank is also the same as an anoxic tank the difference is here aerated bacteria is used for the process. Crossing the marked area puts the water into the next process.
Tertiary Treatment
"Tertiary Treatment" involves further purifying the wastewater using cutting-edge methods including chemical coagulation, flocculation, and filtering to get rid of any contaminants that are still present.
Neutralization Tank
An electric motor brings the water to this tank. Here, acid is used to neutralize the water. Here, the pH of water becomes neutralized. There is a pH meter that automatically adjusts the level of acid or alkali in this tank. The main task of this tank is to control the pH and make the water neutral.
Oxidation Tank
After the filtration tank, water is collected in a tank and oxygen is passed by an electric machine. A line of oxygen is used in the lower part of the tank so the oxygen can easily be mixed with the water. This oxygen-mixing machine makes a lot of noise. The oxidation tank is generally larger than other tanks.
Clarifier Feeding Tank
After oxidation, the water is passed into a tank that is situated lower than the oxidation tank. This tank is called a clarifier feed tank. The water containing more sludge just passes by a lower tank that is connected by a sludge-recycled tank and the rest of the water passes to the clarifier.
Clarifier
It is a circle-type machine that is connected part by part to each other from the lower part to the upper part with a powerful motor that has ceiling fan-like blades around it. It moves circularly and all the extra sludes are breaks with the blades here. This move collects all the extra sludge and puts them in the clarifier feeding tank. Then the process starts again from the clarifier tank. The rest of the water is put in the next tank.
Oxygen Increase Tank
After adding oxygen the water becomes useable for animals and human beings and it contains no waste materials in it.
O2
+ Organic compound = CO2 + H2O + Heat
Blowers: Blower machines are used for passing oxygen to the tanks.
Disinfection
The process of treating effluent to get rid of dangerous germs using techniques like UV or chlorination.
Microfiltration
This is an electric machine bigger in size by which filtration of water is done. The sludge that is literally failing to be collected from the sludge recycle tank is collected here by this machine. This removes all the sludge from the water and collects it in a bag that is easily visible and recyclable.
Sludge Treatment
During the treatment process, sludge is produced. This sludge must be managed, which may include dewatering, drying, and correct disposal or reuse.
Sludge Thickener
After adding more oxygen, a sludge thickener is added to another tank that removes the extra sludge.
Sludge Recycle Tank
After the treatment with bacteria, the water is stored in this tank. Here the sludge is gathered. A high level of sludge can be seen and collected from this tank.
Discharging Tank
This tank is used for the storage and discharge of treated wastewater into nature.
Conclusion
Textile producers can greatly lessen the environmental impact of their operations by putting in place an effective ETP. The treated effluent can be used for non-potable applications, such as irrigation, or safely discharged into bodies of water. The sludge produced during the treatment process can also occasionally be further processed for reuse or even transformed into energy through a variety of techniques.