Project Overview

To operate Iatan Generating Station 2, the Environmental 

discharge permits would have to be modified to allow discharge 

of the FGD scrubber wastewater. The permitting process can 

cause extensive delays to a project. It was decided that going 

to Zero Liquid Discharge would improve the environmental 

footprint of the power station while minimizing delays to 

bringing Iatan Generating station 2 on line.

Project Profile

The Facility 

The 670-Megawatt Iatan Station 1 and the 850-Megawatt Iatan 

Station 2 are coal-fired electric generating stations located 

approximately 30 miles northwest of Kansas City, Missouri near 

Weston, Missouri. To meet strict air quality requirements, the 

facility installed a wet flue gas desulfurization (FGD) system and 

included an FGD wastewater treatment system. The wastewater 

treatment system allows the FGD scrubbers to achieve zero 

liquid discharge (ZLD).

The project was engineered and constructed by Burns & 

McDonnell for the Kansas City Power and Light utility. Iatan 

Generating Station 1 began operation in 1980 and Iatan 

Generating Station 2 will be operational in 2010. The FGD 

wastewater treatment system began operation in May 2009.

Aquatech Supplies Zero Liquid Discharge Treatment for FGD System at the Iatan Generating Station

Project Profile #66 www.aquatech.com
Scope of Service

Aquatech supplied a solids contact clarifier followed by 

two mechanical vapor compressors driven seeded slurry 

Brine Concentrators. The water treatment design for Iatan 

Station is a 1 x 60 gpm clarifier followed by 2 x 30 gpm brine 

concentrators operating in parallel. The Brine Concentrators 

reduce the volume of wastewater allowing for final disposal 

by mixing with fly ash.

The Iatan Station FGD scrubber blowdown contains high 

concentrations of hardness, chlorides and suspended solids. 

The first stage of the water treatment system is a solids 

contact clarifier to reduce the concentration of suspended 

solids in the feed to the evaporators. Chemicals dosed to the 

clarifier include coagulant and polyelectrolyte to enhance 

settling and removal of suspended solids. The generated 

sludge is dewatered with a belt press prior to disposal.

The clarified scrubber blowdown is processed by the Brine 

Concentrator system. A parallel configuration was designed 

that uses 2 x 30 gpm Brine Concentrators to reduce the 

wastewater volume. The Brine Concentrators produce a 

high purity distillate stream that is recycled to the plant’s 

water system. The distillate purity achieved at Iatan is 

less than 10 ppm total dissolved solids. The concentrated 

wastewater leaving the Brine Concentrator system is sent to 

the fly ash silo where it is mixed with the fly ash for disposal 

at the on-site landfill.

The minimization of wastewater using evaporation and 

disposal of the concentrate with the fly ash is an elegant 

solution that avoids the higher capital and operating 

costs of a crystallizer and solids removal device. The high 

purity distillate can be used for boiler feedwater providing 

additional operational savings.

Project Profile

Aquatech Supplies Zero Liquid Discharge Treatment for FGD System at the Iatan Generating Station

Project Profile #66 www.aquatech.com

Design FGD Wastewater Analysis 

Design Flow Rate 60 gpm

Calcium 4,250 ppm

Sodium 590 ppm

Iron 15 ppm

Sulfate 1,320 ppm

Fluoride 12 ppm

Silica 28 ppm

Magnesium 950 ppm

Potassium 25 ppm

Chloride 10,000 ppm

Nitrates 90 ppm

M-Alkalinity 20 ppm

TSS 30,000 ppm
Aquatech Supplies Zero Liquid Discharge Treatment for FGD System at the Iatan Generating Station

Project Profile #66 www.aquatech.com

Project Profile

Process Flow Diagram