Application of the Filter Press in Plastic Washing Wastewater Treatment

The application of filter presses in plastic washing wastewater treatment is very critical, especially in achieving water resource reuse and sludge reduction, playing an important role in solid-liquid separation equipment. Below, we will analyze in detail the application of the filter press in plastic washing wastewater treatment.

Characteristics of Plastic Cleaning Wastewater

A large amount of wastewater is generated during the plastic recycling and cleaning process, mainly from crushing, cleaning, rinsing, and other processes. This type of wastewater generally contains:

High concentration of suspended solids (such as sediment and plastic debris)
High COD and BOD content (due to residual organic matter and detergents)
Grease and glue impurities (especially when cleaning agricultural films or waste packaging plastics)

If it is discharged directly without treatment, it will have a serious impact on the environment. Therefore, efficient solid-liquid separation and water purification processes are required, among which the filter press is one of the key equipment.

Specific Operation Process

Preparation phase

Check the equipment status and ensure that the hydraulic system works normally. Check whether the filter cloth is flat, undamaged, and properly tensioned. Check whether the feed pump and pipeline are unobstructed and leak-free.

Start the oil pump and press the filter plate to form a sealed filter chamber.

Feeding

Start the sludge pump to transport the sludge in the plastic washing wastewater to the feed port of the filter press.

The sludge enters each filter chamber, and under the action of the pump pressure, the liquid is filtered out through the filter cloth and enters the liquid collection tank or reuse system. The filter cloth intercepts the solid matter and gradually forms a filter cake, filling the entire filter chamber.

Stop feeding and maintain pressure

When the filter chamber is full of filter cake, the pressure increases, and the pump flow rate decreases significantly. After the automatic control system or manual judgment, the feed pump is turned off, and the pressure maintenance stage is entered to further squeeze the free water in the mud cake.

Pressure relief and plate opening

The hydraulic system relieves pressure and loosens the compressed filter plates. The filter plates are automatically or manually pulled apart one by one, and the mud cake falls into the mud receiving trough or conveyor belt due to gravity or vibration.

Filter cloth cleaning

Rinse the filter cloth with high-pressure water to remove residual mud residue, avoid clogging the aperture, and maintain good filtering performance.

Advantages of Filter Press

High dehydration efficiency: can reduce the moisture content to below 60%, which is convenient for sludge transportation or incineration.
Stable operation: a mature mechanical structure that is adaptable to different mud characteristics.
Space saving: the filter press is relatively compact and suitable for factory installation.
Conducive to water recycling: the dehydrated filtrate can be returned to the front stage for cleaning or enter the next treatment process, reducing the overall water cost.

Notes

Reasonable selection and reagent matching: Different types of plastics correspond to different wastewater components. The appropriate filter press model and the type and dosage of reagents should be selected according to the solid content and mud quality.

Filter cloth material: Selecting filter cloth that is chemically resistant and easy to clean, such as polypropylene, can improve operating efficiency.

Regular maintenance: Clogging of the filter cloth or failure of the hydraulic system will directly affect the treatment effect, and a regular maintenance system should be established.

Summary

The filter press is an indispensable solid-liquid separation equipment in the treatment of plastic washing wastewater, and it is especially suitable for treating wastewater sludge with high concentrations and high impurities. Through reasonable process design and equipment selection, it can not only effectively reduce emission pollution, but also promote the resource utilization of wastewater and improve the overall economic benefits of recycling.

Application of the Filter Press in Plastic Washing Wastewater Treatment