Application of Filter Press in Phosphorus Chemical Wastewater Treatment

Application of Filter Press in Phosphorus Chemical Wastewater Treatment

In the phosphorus chemical industry, wastewater treatment is an important link, and the filter press has become a key equipment for treating phosphorus chemical wastewater due to its efficient solid-liquid separation ability. The following is a detailed description of how to use the filter press to treat phosphorus chemical wastewater.

Recessed Plate Filter Press

Introduction of Recessed Plate filter press A recessed plate filter press is batch-operated filtration equipment that is used for solid-liquid separation of various suspensions,...

Read More

What is Phosphorus Chemical Wastewater?

The so-called phosphorus chemical industry is a chemical industry chain based on phosphate rock resources. The upstream of phosphorus chemical industry is phosphate rock, the intermediate products are mainly yellow phosphorus and phosphoric acid, and the final products are phosphate fertilizer, phosphate and iron phosphate.

Characteristics of Phosphorus Chemical Wastewater

Complex composition: contains high concentrations of phosphate, heavy metal ions, and suspended solids.

Strong acidity and alkalinity: pH value may be low and has certain corrosiveness.

High processing difficulty: It is necessary to achieve efficient phosphorus removal, heavy metal removal, and solid-liquid separation.

Application Cases

In phosphate fertilizer production or phosphate rock processing, filter presses are usually used to treat the following wastewater:

1. Phosphoric acid production wastewater: rich in phosphates, filter presses can effectively recover valuable substances in it.
2. Phosphogypsum wastewater: separate phosphogypsum particles to reduce suspended solids pollution in water bodies.
3. Phosphorus chemical pickling wastewater: remove heavy metals and acidic pollutants to reduce emission risks.

Filter Press Treatment of Phosphorus Chemical Wastewater Process

• Pretreatment stage
  Sedimentation and flocculation: Add flocculants (such as PAM) and precipitants (such as lime, and aluminum sulfate) to make phosphates and heavy metals in wastewater form flocs or precipitate particles.
  Homogeneous stirring: Evenly stir in the sedimentation tank to ensure that the chemical agents react fully.
• Feeding stage
  The pretreated wastewater is pumped to the filter press. The feed pressure gradually increases and is generally controlled at 0.4-0.8 MPa (the specific pressure is adjusted according to the nature of the wastewater and the model of the filter press). Ensure uniform feed to prevent uneven force on the filter plate.
• Filtration stage
  As the pressure increases, the solids in the wastewater are trapped on the filter cloth to form a filter cake, and the clear liquid flows out through the filter cloth. The pressure gauge is continuously monitored. When the set pressure is reached and the filtrate flow rate slows down, the filtration process ends.
• Pressing stage (optional, suitable for diaphragm filter press)
  The filter cake is pressurized and dehydrated for a second time to further reduce the moisture content of the filter cake. The pressing medium can be air or water.
• Unloading stage
  Stop feeding and open the compacting device. Automatically or manually peel off the filter cake, and collect and process the filter cake. Check whether there is residual filter cake on the surface of the filter cloth, and clean it in time if necessary.

Advantages of Filter Press

High separation efficiency

Solid-liquid separation is achieved through mechanical pressure, which is more efficient than natural precipitation and other separation methods.

Strong adaptability

Whether it is high-concentration, highly corrosive wastewater, or complex phosphorus chemical wastewater, the filter press can handle it. Plate and frame, diaphragm, or other types of filter presses can be selected according to the characteristics of the wastewater.

Automated operation

Modern filter presses are mostly equipped with automatic control systems, which can realize automatic feeding, filtering, pressing, unloading, and other operations, reduce manual intervention, and improve processing efficiency.

Reduce processing costs

The moisture content of the filter cake is low, which reduces the energy consumption of subsequent drying treatment. Effectively recover by-products such as phosphates to improve economic benefits.

Strong equipment durability

Filter cloths and filter plates are usually made of acid-resistant, alkali-resistant, and corrosion-resistant materials, which can adapt to the special chemical properties of phosphorus chemical wastewater and extend the life of the equipment.

Conclusion

The filter press has become a key equipment in phosphorus chemical wastewater treatment with its efficient and reliable separation ability. It can not only significantly improve the treatment efficiency, but also achieve the goal of wastewater resource utilization and emission reduction, bringing both economic and environmental benefits to enterprises.