CHICAGO — While a laundry’s wash process results in clean, fresh linens, it also leaves behind dirty water, and what becomes of that water and the potential pollutants in it should be of importance not only to businesses, but their customers and the community at large. How laundries manage wastewater goes hand-in-hand with other efforts to conserve, reuse and be more environmentally conscious.
American Laundry News spoke to industry professionals representing the chemicals sector and wastewater treatment equipment manufacturing, as well as an industrial laundry operator, to get their take on the interplay between wastewater treatment and the laundry’s other processes and environmental goals, and to discuss how treatment presents benefits and challenges for those in the industry.
WASTEWATER TREATMENT: THE BASICS
Laundries of all types have adopted technologies and processes to be sure water used in the wash process has been properly treated before it goes to the sewer. These systems can range from fairly simple to extremely complex.
John Schultz, senior WEW (water, energy and wastewater) solutions manager for textile care at Ecolab, says pre-treatment before discharge could involve a system as simple as a settling pit, a shaker screen, a heat exchanger, and sulfuric acid for neutralization of the water’s high alkalinity.
“Most laundries have those basic components in place,” Schultz says. “And it’s primarily to remove suspended solids, to lower the temperature, and to … neutralize the alkalinity.”
Schultz says two key pieces of technology—a dissolved air flotation (DAF) unit and a ceramic air filtration (CEF™) system—can help laundries remove even more pollutants, including tough oils and greases, and help lower the biochemical oxygen demand (BOD) and chemical oxygen demand (COD) in the water, which often come with discharge limitations from municipalities.
With the passage of the Clean Water Act in 1972, which sought to prevent water pollution throughout the nation, wastewater treatment became an important technology for laundries concerned about compliance with the law.
James Buik, president of Chicago-based uniform and textile rental company Roscoe Co., says in the early 1970s, his father, Don Buik, worked with Winchester Chemical Co. in Franklin Park, Ill., the U.S. Environmental Protection Agency (EPA) and industry associations on a project to develop and test the first dissolved air flotation unit.
After some experimentation, the groups were able to develop a functioning wastewater treatment system, which Buik says makes Roscoe the company with the longest-running record of compliance with the Clean Water Act of any company in the industry.
“We knew that regulation—the Clean Water Act—was passed, so my dad knew that regulations were coming down the pike that were essentially going to threaten the industry if they didn’t come up with a way to comply with those regulations,” Buik says.
With the DAF system, a sophisticated pump injects “billions of tiny bubbles into the water,” which float to the surface with chains of soil, creating a “sludge blanket” that can be skimmed off and disposed of or treated further, Buik explains. The technology is just one piece of the larger treatment process.
At Roscoe, it all starts with equalization of the water, an important step to consider if processing a variety of product types with different soil levels that could cause soil-level spikes in the water.
“Consistency is the key to running any wastewater treatment system, and the key to that consistency is having tanks or pits that you can collect the water in and allow that water to equalize before you send it over to the treatment system,” Buik says.
Once equalized, the water goes through a shaker screen to eliminate solids, then into chemical chambers, and finally into the DAF. A plate-and-frame filter press can further extract the water from the sludge created by the DAF, resulting in a non-hazardous dry “cake” that can be disposed of in a landfill.
Schultz says the ceramic element filtration system can prepare the wastewater to be recycled back to the wash floor, depending on the business’ customer base and whether or not the water contains dyes or pigments.
MAINTAINING COMPLIANCE
Besides environmental concerns, surcharges, fines and violations are often the drivers behind a laundry’s investment in wastewater treatment technology.
Randall Jones, president of Wastewater Resources, says laundries may be limited as to how much water they can discharge, and may also have limitations on the quality of that discharged water.
“There are some cases where the laundry is paying so much for water and sewer that they want to treat it, but it’s more often that there are some statutory limitations,” he explains.
Schultz explains that municipalities establish a set of effluent guidelines based on their pretreatment program and their National Pollutant Discharge Elimination System (NPDES) permit. A publicly owned treatment works (POTW) will consider not only EPA guidelines, but also what water is coming in from local businesses and industries in order to come up with regulations based on the “number of players,” or “how many people get what slice of the pie,” according to Schultz.
A recent change affecting laundries, he says, involves the reclassification of waterways by POTW. Waterways that were once simply described as “navigable” are now being considered “recreational,” meaning people can walk, swim or fish in the water.
With this change comes more stringent guidelines, and a new way of getting businesses to pay their share of the water treatment costs: Rather than demanding a surcharge as in the past, businesses are now being hit with notices of violations, and fines, for being out of compliance.
Phil Anderson, vice president of operations at Industrial Waste Water Services, says surcharges and fines for BODs, suspended solids, and oils and greases make the decision to treat water before discharge easier for many laundries.
“So, once it reaches a point where the fines are high enough, the company says, ‘All right, I need to do something,’” he comments. “They’ve got to meet discharge limits, and once the money gets high enough, they go ahead and buy the equipment.”
Check back Tuesday for the conclusion!
Have a question or comment? E-mail our editor Matt Poe at [email protected].