A Cut and Dry Answer

April 2, 2018
Michigan water treatment plant installs dry scrubber to help prevent accidental chlorine releases

Purafil Environmental Systems Division

2654 Weaver Way * Doraville, GA 30340

Phone 770/662-8545


The largest fresh water treatment plant in Michigan recently purchased a Purafil ESD Emergency Gas Scrubber (EGS) to prevent accidental chlorine releases more simply, safely and efficiently than their former wet scrubbing system.

The Springwells Water Treatment Plant is a 540-mgd surface water treatment plant located in a mixed residential and light industrial area on the west side of Detroit. Built in 1931, the plant draws water from the Detroit River, while output feeds a distribution system serving approximately 125 communities and 4.3 million consumers.

Because source waters are low in organic content, Springwells uses chlorine stored in one-ton containers as the primary disinfectant. The plant previously employed a sodium hydroxide wet scrubbing system to neutralize the chlorine in the event of an accidental release. However, this system contained a highly corrosive lye solution that was hazardous to system operators and attacked piping, valves, and pump seals.

Less maintenance

Keeping the wet scrubber operational required extensive maintenance and ultimately, the system fell into disrepair, with only the fans working in its last days.

When Springwells replaced the entire chlorine storage and feed facility, they also replaced their wet scrubber with a Purafil ESD EGS.

“The EGS dwarfed the former wet scrubbing system,” said Richard Pernal, filtration supervisor at the Springwells plant. “With nearly a tenfold increase in storage and feed capacity, special emphasis was given to reliability and safety. A sister plant in our system had upgraded to a Purafil dry scrubber recently with favorable results. With our system upgrade, the same scrubber was specified.”

The EGS requires significantly less maintenance than a wet scrubber. Accordingly, it does not need heaters for outdoor applications, and its only moving part is a blower. Instead of using liquid caustic, the EGS neutralizes chlorine with dry-scrubbing media, which a highly porous, spherical pellets that permanently transform gas into harmless solids.

As long as media do not react with chlorine, they do not need to be replaced; they only require occasional testing to determine remaining life and to project change-out dates. Non-toxic and non-hazardous media do not require special handling and can be disposed in landfills.

“The EGS has been especially trouble-free,” said Pernal. “There are no corrosive liquids to handle, no valves to foul, no spills to contain. The scrubber’s operation is checked on a weekly basis, and our local Purafil representative periodically visits to sample the dry-scrubbing media for analysis.”

Pernal continued to praise the EGS at the Springwells facility.

“Our system looks and performs today as well as day one, with virtually no maintenance,” he said. “The maintenance savings are great and operations has a system that is not dangerous to operate. We’re very happy with the Purafil dry scrubber.”