Customer Requirements
The customer required a comprehensive reconstruction of the paint shop wastewater neutralization plant with the objective of ensuring reliable wastewater treatment, compliance with discharge limits for sewer release, and enabling the recycling of part of the treated water back into the production process.
The main project requirements included:
- design capacity of 2 × 15 m³/h,
- stable and controlled neutralization and suspended solids separation process,
- fully automated operation with minimal operator intervention,
- complete technology delivery including engineering, control system, and commissioning.
Initial Conditions
Wastewater from the paint shop showed variable composition and flow rates, including elevated suspended solids concentrations and fluctuating pH values. This required continuous operator supervision and frequent process adjustments.
The existing system did not allow sufficiently stable process control nor efficient recycling of treated water. Therefore, a new water treatment technology with separate lines for the following purposes had to be designed:
- discharge to the sewer system,
- reuse of water within the production process.
Proposed Solution – ENVITES Technology
ENVITES designed and supplied a complete neutralization plant technology comprising:
1️⃣ Wastewater Homogenization
- homogenization tank for accumulation and equalization of incoming wastewater quality,
- controlled pumping of individual streams using flow meters.
2️⃣ Coagulation, Alkalization, Flocculation and Separation Units
- two parallel process lines (sewer discharge / water recycling),
- coagulation reactors with ferric sulfate dosing,
- alkalization reactors with automatic pH control using NaOH,
- flocculation chambers with polymer flocculant dosing,
- lamella separators for efficient sludge separation.
3️⃣ Sludge Treatment Line
- common sludge thickener for both process lines,
- sludge dewatering using a filter press,
- handling of the filter cake by container.
4️⃣ Water Management and Equalization Tanks
- clarified water tank,
- accumulation of utility water,
- automatic pressure booster station for reuse of treated water in the process.
5️⃣ Chemical Dosing
- automatic preparation and dosing of flocculant,
- dosing of coagulant and sodium hydroxide directly from transport containers,
- dosing control based on flow rate and pH values.
Process Control
The entire process is controlled by a PLC system with a touch-screen operator panel:
- automatic control of chemical dosing,
- monitoring of flow rates, pH and operational statuses,
- possibility of algorithm optimization during trial operation,
- clear and intuitive visualization for operators.
Project Implementation
- preparation of complete project documentation,
- technology supply including electrical and control & instrumentation systems,
- equipment installation,
- commissioning,
- trial operation with comprehensive performance testing.
Project Results
✅ Stable wastewater treatment at a capacity of 2 × 15 m³/h
✅ Compliance with sewer discharge requirements
✅ Possibility of recycling treated water back into the production process
✅ Fully automated operation with minimal operator requirements
✅ Reliable sludge treatment line with sludge dewatering
Conclusion
The reconstruction of the neutralization plant provided the customer with a modern, stable and fully automated solution for paint shop wastewater treatment.
By combining chemical precipitation, lamella separation and efficient sludge processing, both environmental and operational objectives were achieved, including the reuse of treated water.
