In 2011, a pulp and paper manufacturer located in the Northeastern U.S. required a modification to their existing process that would improve production efficiencies while also meeting stricter environmental standards. Specifically, the company sought a solution to reduce valuable fiber loss, minimize chemical use and decrease produced solids in the effluent discharge.
Evoqua's DAVCO™ product line was contacted to present options to meet the company’s production improvements, while also helping them to be more competitive and reduce operating costs.
After evaluating the production process, Evoqua filtration product experts recommended the Forty-X™ Disc Filter to address the manufacturers' effluent discharge challenges. The Forty-X Disc Filter includes pleated media technology which allows suspended matter to be readily removed while larger contaminants are passed through and out of the system to be collected downstream of the media. This feature keeps larger contaminants from blocking media filtration surfaces which improves filtration performance and extends the system’s run length before backwashing is required.
Disc filters have been used since the 1980’s, primarily as a means to achieve greater levels of suspended solids removal in tertiary wastewater treatment systems to meet local regulatory requirements and environmental restrictions. In pulp and paper processes, a disc filter improves consistency control by minimizing fiber loss and reintroducing the fiber to the sheet earlier in the process. This diminishes or eliminates the need to sweeten the process with the injection of additional fiber and results in improved return on investment by lowering operating costs and having an immediate impact on daily cost per ton.
In 2012, the pulp and paper manufacturer signed an agreement with Evoqua's DAVCO™ product line to conduct a full scale pilot test of the Forty-X Disc Filter system. Performance testing included a full range of hydraulic and solids loading conditions to replicate potential real-world conditions and to define process limits.
After a successful trial, a permanent installation was executed in the Fall of 2012. Operational results indicate that the system achieved up to 90% or better removal of particulates and solids as well as COD and BOD reduction in moderate to severe solids loading conditions.
Evoqua's Forty-X Disc Filter system featured a pre-engineered design, minimizing the level of onsite and installation labor required. The compact design also provided high capacity filtration within a minimal footprint area as compared to conventional sand filtration systems.
Since installation of the system, the customer has realized savings in thousands of dollars per day based on recovered fiber losses that were inherent in the previous system design. The customer indicates that the daily savings in cost per ton has resulted in a positive return on investment.