APTsorb - Water Remediation Media
The toxin-filtering ability of peat and wetlands is well-documented, but until now, natural peat has not been a widely-accepted alternative for water treatment because of the short-comings of raw peat. APTsorb harnesses the affinity of natural peat for heavy metals, but transforms it into a hardened granule with favorable hydraulic conductivity. The media has the structural strength that is essential in water treatment processes and offers low-cost, robust treatment in challenging environments.
APTsorb is effective against dissolved heavy metals such as lead, copper, cadmium, zinc, chromium, nickel and cobalt. Additionally, the angular granular structure of the media acts as a physical filter, removing particulates all the way down to 5 microns. In many cases, APTsorb treats both suspended and dissolved metals in the same contact vessel. In the proper system design, APTsorb can be back flushed to remove solids and extend treatment life.
Modern lifestyles require a lot of water. The average American uses 80-100 gallons of water each day and many industries use hundreds of thousands of gallons each day to manufacture the products and materials we rely on. Water is simply too precious to treat as disposable. When heavy metals and particulates are a concern, use robust, economical APTsorb to remediate contamination and prepare water for reuse or release.
The capacity and mechanisms of sorption by peat has been widely recognized. Because of the geochemical environment of deposition, peat naturally tends to reject innocuous metals such as calcium and magnesium while attracting and bonding with more toxic metals such as lead and cadmium. APTsorb captures those affinities of natural peat and transforms it into an easy-to-use granular media.
APTsorb can be deployed in challenging conditions that may be problematic for other resins. It tackles difficult suspended solids without fouling the media surface or compromising its sorption capacity. Add APTsorb to the front end of a water treatment train to protect valuable, high-end resins and treatments from solids. The media can be backwashed in pressure vessels to remove particulates and extend treatment life.
APTsorb can be used in almost any water treatment configuration. Use the media in pressurized tanks, gravity feed vaults, downspout filters and booms where there is some control over flow rates and good media/water contact can be made.
APTsorb is a low-cost, low-input answer to complex water treatment problems. The robust nature of the media translates into less infrastructure and labor costs. Talk to our experts about how to design an effective and efficient treatment system that takes advantage of the unique characteristics of APTsorb while meeting your compliance goals.
APTsorb can be used in almost any structure, tank, vault, boom sock or in-ground cell as long as the flow rate can be controlled and good media/water contact can be made. APTsorb is cost-effective for most applications and its capacity is dependent on the metals of concern, competing ions and water chemistry. The media can also be used in a treatment train to polish water prior to discharge or to remove selected ions within the treatment system.
It meshes well with standard equipment, but there are a few things to keep in mind when considering a retrofit to APTsorb.
- APTsorb is an organic media, so it requires a certain amount of residence time. More specifically, the performance of the media is sensitive to the velocity of the water. If the water is flowing past the media too quickly, the media does not have time to form bonds with the metal ions as they travel past. Recommended velocities are dependent on the type of metal, concentration levels and background chemistry, but a general rule of thumb is to keep the velocity less than 33 ft/hr (10 m/hr). Our flow and volume calculator can give some general guidance on system designs.
- In most cases, it is preferable to keep the ratio of bed height to bed diameter less than one. A shorter, squatter contactor is preferred over a taller, thinner vessel. Given the recommended velocities above, this configuration allows for a favorable volume of water to be treated while maintaining the residence time.
- A lead/lag system will extend the life of the media as well as allow for some shortcomings in system design. The many mechanisms at work in the natural peat have different coefficients of performance, which means that the media responds robustly to different system parameters. A lead/lag system can utilize more of the different loading mechanisms than a single-pass treatment system.
- In addition to its sorptive capacity, APTsorb will act as a physical filtration media. The angular, polar surfaces of the media are very effective at sequestering solids within the bed. The efficacy of APTsorb depends on the characteristics of the solids, but removals exceeding conventional sand filters are possible.
- If suspended solids are a concern, a vessel that allows for backwashing will extend the life of the APTsorb media. Backwashing rates can vary depending on the nature of the solids, but 10-15 gpm/ft2 is sufficient to lift the APTsorb bed in most cases.
- Regeneration of the APTsorb media is not recommended. The media forms very stable double bonds with metal ions, and regeneration is usually incomplete and unwieldy. Once the media is exhausted, disposal is recommended.
- Disposal of spent APTsorb is dependent on local regulations and how the media was loaded. We recommend performing a TCLP test (EPA 1311) or total constituent analysis on the media. For most metals, with the exception of lead, under normal loading conditions, we anticipate that the media will pass the TCLP.
Prior to deploying APTsorb in new applications, a treatability test can offer some assurance that APTsorb is the right solution. We often provide complimentary treatability testing in our research and development lab. Our tests assess the effectiveness of our media against your specific water. Please contact us to talk about treatability testing, and expect to provide some preliminary information such as the following:
- What type of water are you treating (stormwater, mine dewatering discharge, truck wash water, etc.)?
- What are the metals of concern?
- What are the concentrations of the metals of concern?
- What is the effluent target concentration?
- What volumes need to be treated?
- What flow rates need to be treated?
- What other background metals are present? (If you have any characterizations, monitoring reports, etc. that would be helpful.)
- How is the water currently being treated?
- What other treatment systems have been tried?
- What are the site limitations (small footprint, airborne contaminants, etc.)?
APTsorb is a versatile water treatment media that meshes well with many existing industries and standard equipment. In addition, once the media is spent, disposal is easy to handle because generally, the media meets the EPA’s TCLP limits and can be disposed of as non-hazardous solid waste.
Industrial uses include:
- Stormwater remediation
- Parking lots
- Construction sites
- Galvanized roof runoff
- Process water treatment
- Manufacturing facilities
- Plating shops
- Acid mine drainage sites
- Mine dewatering
- Abandoned mine remediation
APTsorb lends itself well to conventional filtration equipment, including:
- Open-top or passive containers
- Standard sand filters
- Pressurized contactors
- Boom socks
- Potentially, as an amendment in contaminated soils
In general, APTsorb cannot be regenerated. The complex chemical nature of the bonding mechanisms result in surface-metal bonds that are not easily broken. Regeneration is costly and incomplete. However, the strength of those bonds also translates into favorable leaching results. Although it is up to the end user to determine if spent media meets TCLP limits for non-hazardous waste disposal, current data suggest that spent APTsorb meets EPA guidelines when used in conventional conditions. Contact us for guidance on meeting TCLP limits.
Unlike most synthetic resins, APTsorb’s diverse mechanisms of sorption result in unusual loading curves. Simply put, different cations approach different functional groups in different ways. In that respect, coefficients of kinetic loading are not uniform throughout the life of the granule. That presents some challenges to using APTsorb, but also makes it an attractive solution for many applications.
As mentioned under the Description tab, ion-exchange is most likely one of the primary mechanisms of adsorption. Those sites are extremely active, making APTsorb an excellent candidate for a final polishing step in a conventional treatment regime. If residence times are within limits, APTsorb is simply unwilling to let most metals with a 2+ valance, and some with a 3+ valance, through. Much of our research has centered on cadmium, and current data indicate that the ion-exchange sites, by themselves, can be loaded to about 3.5 mg Cd per gram of APTsorb.
The other functional groups are also active against cadmium. Our data indicate that APTsorb’s total capacity approaches 25 mg Cd per gram. The different coefficients across the loading mechanisms suggest, and our research confirms, that attacking a wastewater with a counter-current stream is effective. As the upstream granule is spent, it is replaced with fresh media at the end of the stream. This takes advantage of the different coefficients of loading and uses the granule to its fullest extent.
APTsorb’s cost-effective pricing structure, which is about a tenth of traditional resins, translates into larger contactors that can address increased flow volumes. For this reason, APTsorb is an ideal candidate for stormwater remediation or applications where large volumes of water are complicated by relatively low concentrations of contaminants.
Although much of our research has focused on cadmium remediation, we have also partially described APTsorb’s activity against copper and lead, and to a lesser extent, nickel, zinc, cobalt, chromium and manganese. Contact us for more information about how APTsorb will perform with your particular wastewater.An Environmentally-Friendly Alternative
Traditional sorption resins are synthetic, petroleum-based polymers. They are an effective tool for wastewater remediation, but in the long run, they are not sustainable. The economic and environmental costs of producing oil can only increase as competing manufacturing sectors continue to demand slices of an-already uncertain natural resource. Even now, factors such as sustainability and actual environmental costs enter more often into thoughtful purchasing decisions. Being green is no longer a secondary, abstract consideration.
APTsorb is not made from petroleum products. It is made from easily-accessible, environmentally-safe peat. From field harvest to final shipping, we strive to be a good steward of the resource entrusted to us. And in many ways, our raw material makes it easy for us. Harvesting peat is much more like farming than mining. The material is essentially harmless at all stages: in the deposit itself, in processing, in transport and in use by the consumer. Unlike petroleum, the site where peat is harvested, while certainly disturbed, is not inhospitable. We often see wildlife on our peat fields, and we comply with strict de-watering regulations to ensure that we are not sending any problems downstream.
Technically, and according to the US definition, peat is not a renewable resource. Finland is the only country to classify peat as renewable. At an accumulation rate of about 3 centimeters per year, most long-range business plans, including our own, take into account the value of the current resource. We have acquired a core of knowledge about alternative raw materials in our desire to produce a truly sustainable product. For instance, we already know that certain composting processes can produce a raw material not unlike our current peat. Our research includes efforts to produce a consistent, high-quality raw material using natural and native vegetation. We hope that in the future we will be offering a filtration media that is 100 percent sustainable, through the use of low-value, diverse cover crops that convey environmental benefits during the growing season. In the meantime, we will continue to judiciously harvest our current deposit so that we can explore the market for a safe and environmentally-friendly alternative to petroleum-based resins.
Check out our Plant Operations page under the Technology link for more information about how we continually seek to green our production of our entire line of products.
Our harvesting operation uses low-impact equipment to gently remove only the top several inches of our peat deposit each year. There are no open pits or gaping scars in our peat fields. Our deposit is only a mile away from our processing plant, which means that we are not using precious resources to truck raw material long distances. Inside our processing plant itself, we use a bio-fuel combustor to do the bulk of our drying operations.
APTsorb is an innovative, environmentally-friendly sorption media for dissolved heavy metals. It is made of physically-, thermally-, and chemically-modified red-sedge peat harvested from the abundant reserves of North America. It capitalizes on the known sorption mechanisms and capacities of natural peat while improving on those qualities that have limited peat’s use in wastewater treatment in the past.
APTsorb is a low-cost alternative to traditional resins and excels in applications such as polishing prior to discharge, storm water treatment, and waste waters with low pHs.