- Wastewater Treatment & Partial ZLD System
We provided engineering, procurement, construction and startup/commissioning services for the addition of a wastewater treatment and partial zero liquid discharge (ZLD) system for a four-unit power station. The project consists of a thermal vapor compression ZLD system for treatment of wet flue gas desulfurization (FGD) blowdown.
The FGD side stream clarification process removes suspended solids to allow increased cycles of concentration within the FGD systems to reduce FGD blowdown flow requirements. Each unit has an individual wet FGD system that produces a combined wastewater stream of approximately 300 gpm with 2,000-3,000 ppm concentration of chlorides. The FGD softening system reduces hardness levels and suspended solids in the feed stream to the thermal ZLD system. The feed stream to the evaporator is preheated with hot distillate generated by the process. The seeded slurry evaporator concentrates the stream using aux steam and vapor compression technology.
The station drains treatment system consists of a clarification process with enhanced metals reduction. The effluent from the clarifiers is polished in a mercury reduction sand filtration system. The guaranteed system effluent is less than 12 ppt (monthly average) and 20 ppt (daily maximum) mercury. Solids removed in the systems are dewatered using three filter presses and are landfilled.
- EPC services
- Project management
- Detailed design
- Procurement and expediting
- Construction management
- Field engineering
- FGD side stream clarification system
- FGD blowdown softening system
- Thermal ZLD (combination with fly ash) from wet scrubber system
- Station drains physical/chemical clarification and polishing mercury system
- Associated dewatering facilities