Carbon reactivation is the process of utilizing 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. Furthermore, reactivation destroys 99.99% of the removed organic contaminants through a combination of chemical reactions and oxidation in the reactivation plant’s afterburner. The reactivation process thus ends the liability associated with disposing and handling of the adsorbed contaminants, while restoring the surface area and pore volume of the spent carbon to near virgin-grade levels.
The reactivation process recycles spent carbons into new activated carbon materials that continue to provide excellent performance in many treatment applications.
Reactivation can be applied to carbons used in both liquid phase and vapor phase applications. Spent carbons can be segregated from other spent carbons and returned to the same customer for reuse, or pooled with other spent carbons and sold into other applications as a cost-effective alternative to virgin carbon. Evoqua has extensive experience with all of these types of reactivation services.
Reactivation is a sound “disposal” alternative for hazardous and non-hazardous spent carbons. Environmental concerns, changing regulations and increasing costs associated with virgin-grade carbons are among the key drivers shifting generators towards reactivation rather than traditional disposal methods, such as landfilling. Reactivation is generally considered less expensive than other forms of spent carbon disposal and is also considered more environmentally sound. Most importantly, reactivation ends the responsibility or “chain of custody” of the waste producer, thereby eliminating concerns of future liability.
A spent carbon profile is required to ensure that the spent carbon is safely recycled in compliance with Federal, State and local regulations. Before Evoqua Water Technologies can accept spent carbon for recycling, the media has to be characterized as either hazardous or non-hazardous. The generator submits a completed Spent Carbon Profile form accompanied by a sample of the spent carbon. Evoqua can provide assistance with proper sampling of the spent carbon or can also provide instructions for doing so using site personnel. Once the spent carbon is returned to Evoqua, it is analyzed to complete the profiling process. The cost for profiling is dependent on whether the spent carbon is determined to be non-hazardous or hazardous.
Since the spent carbon profiling and analysis process takes time, many customers prefer to complete it in advance. If approved, a spent carbon approval number is issued and filed. Pre-approval improves the subsequent response time for reactivation and carbon exchange services, thereby minimizing any delays or downtime in returning the system to operation.
Once the profile is completed and approved, Evoqua offers carbon reactivation services from three U.S. reactivation facilities. We are the only provider in the industry with facilities serving both the East and West coasts and permitted to handle RCRA hazardous spent carbon. We also operate a network of carbon service branches across the country, putting us within close proximity to our customer base. Our branches are fully stocked with carbon, equipment, trucks, all of which are company owned. This gives us the ability to mobilize resources quickly to address customer needs. In addition to spent carbon profiling and reactivation, Evoqua can assist with spent carbon removal and packaging, non-hazardous and/or hazardous waste handling/transportation to our reactivation plant or a hazardous waste reactivation plant, vessel inspection with minor repair, vessel reloading with reactivated carbon.