Eco-responsible wastewater reuse

Metal Surfaces Inc (MSI) is one of the largest precision plating companies in North America, providing a wide range of water intensive reel-to-reel plating lines including metal completion processes (e.g. cyanide, silver, gold, chromium, nickel, zinc and more), for aerospace, automotive, military, medical and industrial applications. MSI signed a deal with ToxSorb and the plant enabled highly efficient wastewater reuse and high-quality water, along with water and cost savings.

MSI approached ToxSorb following a recommendation from one its consultants, due to the severe water scarcity after California had entered its fifth year of drought. MSI had complex wastewater streams contaminated by a variety of metals. While MSI’s system complied with wastewater discharge permits, the process was inefficient from the point of view of high chemical consumption and the generation of high salinity wastewater that was impossible to reuse. ToxSorb’s experience in Zero-Liquid-Discharge (ZLD), combined with its unique and proprietary adsorption/reduction filtration technology was a perfect fit.

ToxSorb worked with MSI to design a custom filtration system capable of treating a mixed wastewater stream, including all of the hexavalent chromium and cyanide-complexed rinses from the factory. The proposed treatment system incorporated ToxSorb’s proprietary Modified Activated Carbon (MAC) media, capable of reducing hexavalent chromium and oxidizing cyanide inside the filter, without the use of chemicals. The effluent from ToxSorb’s system would need to exceed the highest standards in the metal finishing industry, required for military applications (<50 uS/cm).

ToxSorb’s treatment system was constructed of two basic elements:
Central Treatment System – the main treatment system incorporating a series of 5 columns containing 140 ft3 of mixed-bed ion exchange resins and MAC media, designed for chromium reduction, cyanide destruction and de-ionization <50 uS/cm.
Polish Treatment System – a single MAC column designed to remove any remaining hexavalent chromium and cyanide in the regeneration solution, before discharging to MSI’s general WWTP.

The filtration system custom designed by ToxSorb for Metal Surfaces Inc (MSI) delivered a variety of valuable outcomes, that included the following:

• Water Savings: 20,000 gallons / day saved in fresh water purchase and wastewater discharge
• Chemical Reduction: Elimination of NaHSO3 and NaClO and a reduction in NaOH downstream in the general WTP
• Sludge Reduction: Less sludge production, through the reduction of chemicals and the partial elimination of city water
• Improved Water Quality: Higher quality rinsing water (<50uS/cm)
• Water Independence: Lower impact from supply and demand of water

Today, ToxSorb’s chromium and cyanide reuse facility at MSI is fully operational, and meets its design target for water quality.

Thanks to ToxSorb’s solution, MSI took great advances in increasing its water reuse efficiency – an outcome that made an important contribution to alleviating California’s chronic water shortages. In tandem, the project delivered substantial water cost savings for MSI, reducing its chemical consumption, and, in turn, its ecological footprint.