Ceramic industry wastewater treatment encompasses the wastewater management of tile, sanitary ceramics, porcelain, and refractory production facilities. This sector is distinguished from other industries by the closed-loop application — a large portion of the wastewater is recovered for production.
The main characteristic of ceramic wastewaters is the high MLSS; it varies between 5,000-30,000 mg/L. KOİ is relatively low (200-800 mg/L) because the organic content is limited. Wastewater from the glazing line may contain heavy metals (Pb, Cd, Zn) and colored pigments.
Arsistek's solutions for the ceramic sector include lamella sedimentation, clay dewatering (filter press), closed-loop water recovery, and heavy metal precipitation for glaze. Modern ceramic factories achieve 85-95% water recovery.
Wastewater Sources in the Ceramic Production Line
There are 5 main sources of wastewater in ceramic factories:
- Raw material preparation (glazing, grinding): High COD, clay particles
- Shaping (mold cleaning): Medium level COD, surfactant residues
- Glaze line: Low flow, high pigment and heavy metal
- Press-shear cleaning: Periodic cleaning wastewater
- Water-cooled cutting/polishing: Fine silica particles
The vast majority of these wastewaters (>80%) can be reused after physical treatment. Only the flow from the glaze requires chemical treatment.
Lamella Settling System
Lamella (inclined plate) clarifier is the most effective physical treatment technology for ceramic wastewater. It offers 5-10 times the surface area of conventional clarification.
By adding a poly-electrolyte flocculant, clay particles are collected in large flocs. The effluent water's AKM is reduced to <50 mg/L and is returned directly to production.
Clay Sludge Dewatering
Sludge coming from the lamella is dewatered in a filter press — 65-75% dryness is achieved.
Options for re-evaluating the dried clay cake: reuse as raw material (5-15% additive), brick/ceramic raw material, construction fill material, or cement industry.
Special Treatment for Glaze Line
Glaze wastewater is small in volume (<5%) but is chemically the most complex effluent. The substances it contains:
- Zinc, lead, cadmium, chromium, barium (colored pigments)
- Boron (glass phase former)
- Color pigments and glass frit
This effluent is collected separately and undergoes the following processes: thickening → raising pH to 9-10 → hydroxide precipitation → sulfite (for stricter limits) → lamella → filter press.
The effluent water is mixed with the output after the main lamella system. The sludge is classified as hazardous waste and requires licensed disposal.
Advantages of Solutions in the Ceramic Sector
Ceramic Industry Reference Projects
8 visuals will be added soon — stay tuned for our reference projects and facility photos.
Frequently Asked Questions
Ceramic wastewater primarily consists of inorganic (clay, silicate, oxide) pollutants. The COD is low (200-800 mg/L). Therefore, physical-chemical treatment is sufficient. There is only a slight organic load during countertop washing.
Yes. The dewatered clay cake has a dryness of 60-75% and can be mixed with the raw material body at a rate of 5-15%. If its quality is low, it is used for bricks, cement, or construction fill.
Glaze contains heavy metals and colored pigments. If mixed with the main flow, all clay sludge falls into the hazardous waste category. By collecting it separately, only the glaze sludge remains in the hazardous category, and the clay can be reused.
Lamella outlet (AKM <50 mg/L) is returned directly to the production pools. Approximately 5-15% fresh water supplementation is made to compensate for evaporation + production output + sludge water loss. In-line conductivity is monitored — if salt accumulation occurs, partial blowdown is performed.
Yes. Belt filter press operates more continuously but achieves 50-60% dryness. Decanter centrifuge is compact and fast (55-65% dryness). Vacuum filter is small scale. Filter press provides the highest dryness (65-75%).
Yes, it is possible both economically and technically. With a closed-loop + glaze flow system and a small evaporator/crystallizer, 100% water recovery is achieved. The investment cost is recouped within 5-10 years in the standard industry.