The coagulation/flocculation system doses coagulants and flocculants to destabilize colloidal particles and fine suspended solids that are difficult to settle naturally, and aggregate them into flocs that can settle or be floated, creating conditions for subsequent sedimentation, DAF, or filtration units.
Process Principle
- In the coagulation stage, metal salts or polymers are dosed to compress the electrical double layer of colloids, destabilizing them and inducing micro-flocculation.
- In the flocculation stage, slow mixing and adsorption bridging by polymeric flocculants form large, dense flocs.
- The formed flocs are separated in sedimentation tanks, DAF units, or filters, reducing effluent turbidity and pollutant load.
Product Features
- Effective removal of colloidal matter, fine suspended solids, and some phosphorus and heavy metals.
- Chemical types and dosages can be adjusted according to water quality changes, providing strong adaptability to influent fluctuations.
- Combined with sedimentation, DAF, and filtration, it is a common configuration for wastewater pretreatment.
- Mature equipment structure, simple operation and maintenance, widely available chemicals, and controllable costs.
Application Industries
- Pretreatment for turbidity and color removal in surface water purification and industrial water supply treatment.
- Formation and separation of heavy metal hydroxide flocs in electroplating and metallurgical wastewater.
- Decolorization and suspended solids removal for printing and dyeing and papermaking wastewater.
- Chemical phosphorus removal and sludge conditioning for phosphorus-containing wastewater.
Specifications and Models
| Parameter | Unit | Typical value |
|---|---|---|
| Treatment Capacity | m³/h | 5–1000 (typical, parallel configuration available) |
| Mixing time | s | 30–120 (typical) |
| Flocculation time | min | 10–20 (typical) |
| Common coagulants | — | PAC, PACl, aluminum sulfate, ferric chloride |
| Common flocculants | — | PAM (anionic / cationic / nonionic) |
| Dosing metering accuracy | % | ±2 (typical value) |
The data in the table are common ranges for similar equipment and are for selection reference only; specific specifications, models, materials, connections, and control methods must be confirmed during the selection stage based on water quality, treatment scale, and site conditions.