The challenge was clear. A U.S. producer of pesticides and fertilizers required a permanent way to treat contaminants in rainwater runoff. The company originally employed a rental equipment system, but it wanted the permanent solution to improve treatment performance at a lower cost.

The chemical company approached Siemens Water Technologies with U.S. headquarters in Warrendale, Pa. Siemens provided a PV series adsorber system with two 6' dia vessels on a single-skid arrangement. The system arrived on-site with piping assembled and the activated carbon already loaded, eliminating the need for any further assembly. As part of the pilot agreement, Siemens also offered onsite services, including removal of spent carbon and transportation to Siemens’ RCRA- approved reactivation facility.

Reactivation is the process of using elevated temperatures followed by steam in a rotating kiln or multiple-hearth furnace to remove organic compounds adsorbed onto the carbon during normal service use. AquaCarb S series reactivated carbons provide a cost effective alternative to new virgin-grade carbon, which is viewed as an environmentally friendly solution because there is no need for landfill.

Since implementing the technology, Siemens says the chemical plant has realized significant improvements in both meeting discharge requirements under its state waste discharge permit and reducing operating expenses.

The process of carbon reactivation limits any future liability associated with disposing and handling of adsorbed contaminants. Reactivation destroys 99.99 percent of the removed organic contaminants adsorbed on the carbon surface, which provides a safe and effective means of spent carbon disposal, according to Siemens.