Wastewater Treatment Delivers Environmental Improvements
May 22, 2014
A large paper mill in North America makes high quality, bleached and unbleached Kraft paperboard. The company is committed to maintaining high environmental, health and safety standards. The organization is focused on 100% compliance with all environmental laws, and has a performance goal of zero environmental incidents.
The mill was unable to maintain wastewater compliance due to oil leakage from the paper process. Oil was leaking from a paper machine gearbox and the bulk oil system had overflowed into the primary clarifier, impacting settling. The primary clarifier typically captures 87% of the solids, but due to the bulking issue it was operating at a much lower efficiency level. The solids were instead being carried over to the secondary system which resulted in bulking sludge and high total suspended solids being discharged to the river.
As shown in Figure 1, the implementation of Nalco ULTIMER 1460 reduced total dissolved solids from over 100,000 ppm to less than 25,000 ppm, or 75%, affording consistent environmental compliance. Switching to this program also eliminated the need of more than 5,000 pounds of chemical usage per day, or just less than 2 million pounds of chemical annually. The elimination of these chemicals saves the customer up to $2.9 million on an annualized basis.