MetSorb™

Arsenic, Lead, and Heavy Metal Adsorbent Media

Recently, the U.S. Environmental Protection Agency mandated by law that all drinking water systems meet the new arsenic standard of 10 parts per billion. As a result, removal of arsenic, lead, and other heavy metals from water supplies has become a top priority for many municipalities, small community water systems, schools, and individual consumers.

Graver Technologies has been developing and manufacturing superior water treatment solutions for more than 100 years. Because of the breadth of our technologies, and the depth of our scientific and analytical resources, we're often called upon to solve our customers' most challenging water treatment problems. Our patented MetSorb™ adsorbent products have been specifically engineered to provide excellent Arsenic, Lead, and other Heavy Metal contaminant removal for the purification of drinking water, process water, and other critical purification applications.

MetSorb™ Adsorption Media

Typical MetSorb Properties

MetSorb Features and Benefits:

• Removes As (III) and As (V) to <1.5 µg/L (non-detect)
• High adsorbent capacity for arsenic and lead (>10 mg As per gram of METSORB)
• Extremely Fast Kinetics: Empty Bed Contact Times (EBCT) between 1.5 - 3 minutes
• Reduced equipment footprint
• Simple installation and start-up
• Reduced (in some cases eliminated) frequency of backwash
• Nonhazardous disposal as solid waste - passes EPA TCLP (Toxicity Characteristic Leach Procedure)
• No regeneration Chemicals Required
• Removing Arsenic in millions of gallons of drinking water daily

Results of AWWA Research Foundation Study "Adsorbent Treatment Technologies for Arsenic Removal," 2005

MetSorb™ Application

MetSorb adsorbent media is applicable in a wide range of water treatment processes, from large-scale municipal systems to small-scale residential treatment units. Regardless of the system size, there are operational design parameters that must be considered to ensure effective, trouble-free performance of the MetSorb adsorbent media.

Groundwater or surface water is simply pumped in a down- flow mode through a single or multiple fixed bed pressure vessel containing the MetSorb media. The multiple pressure vessel design is either assembled in Parallel Flow or Series Flow when additional adsorption protection is deemed necessary. Flow to each vessel is measured and totalized to record the volume of water treated. Pressure differential through each vessel is also monitored. Periodic backwashing is typically performed at start-up and every 8-10 weeks thereafter depending on usage and water quality.

Dual vessels containing MetSorb plumbed in series for added consumer protection.

NOTES: Graver recommends treatment system monitoring to determine media breakthrough and change out. Pre-filtration for particulates can greatly reduce frequency of backwash. High levels of iron and magnesium can influence efficiency of MetSorb absorption. EBCT of 3 minutes is recommended for challenging water qualities. Backwash water discharged to sewer or POTW. Direct discharge according to state and local regulations.

Operational Design Parameters

Inlet / Outlet Arsenic Concentration

MetSorb Disposal

MetSorb is operational in numerous locations across the U.S. and Canada, providing much experience in managing the exhausted media. Arsenic (or “heavy metal”) laden MetSorb HMRG 16/60 has been evaluated using both the EPA TCLP (CFR 40-RCRA Regs.) and California WET method,s and has been found to be nonhazardous and safe for landfill disposal. Since each application differs, however, we recommend exhausted MetSorb HMRG 16/60 be evaluated following all federal, state, and local regulations regarding necessary approvals for landfill disposal.

Graver Technologies
Filtration / Separation / Purification
MetSorb™ HMRG Outperforms Competitive Products

MetSorb HRMG outperforms competitive products in pilot study for removal of arsenic from drinking water.

Elevated concentrations of arsenic are found in many regions of the world. Naturally occurring arsenic in drinking water affects about 10% of the drinking water supplies in the United States, especially groundwater supplies. One of those supplies is located in Hopewell, New Jersey. Graver, in conjunction with researchers from Stevens Institute of Technology and scientists from the New Jersey Department of Environmental Protection, conducted a pilot test of the well water to demonstrate an efficient and economical way to reduce the arsenic levels.

Typical Water Analysis

The Testing

Several adsorptive media (an iron-based product), activated alumina, modified activated alumina, and MetSorb HMRG were tested side by side on the Hopewell well water in identical test units.

All were tested with an empty bed contact time of three minutes and the units were run beyond a breakthrough of arsenic in the effluent water of 10 ppb (the new Federal standard for allowable arsenic in drinking water). No preconditioning of the water was done.

Test Results

Based on these tests, the treatment capacity decreased in the following order:  MetSorb HMRG>Iron-based media>Modified activated alumina>Activated alumina. See the table for the total treated number of bed volumes prior to breakthrough.

Performance of MetSorb HMRG vs. Competitive Products

	Results Table: Breakthrough
	Volumes to 10 ppb
	Media	Bed Volumes
	MetSorb HMRG	42,000
	Iron-based media	22,000
	Activated alumina	2,000
	Modified activated alumina	8,000

The complete breakthrough curves are shown in the graph as well and clearly indicate the superiority of the MetSorb HMRG in removing the arsenic.

Operating costs of the MetSorb HMRG system are estimated to be substantially lower than for the other absorptive media. These costs comprise mainly the periodic replacement of the media and the disposal of the spent media (typically adsorptive media for arsenic removal are not regenerable but rather a one-time use). The use of the media is therefore optimized by running two adsorbers in series in a leadlag mode, thereby allowing a greater utilization of the capacity of the MetSorb HMRG. The spent MetSorb HMRG has been tested by the Toxicity Characteristic Leach Procedure and has been determined to be nonhazardous waste.

The operating cost is also very dependable on the inlet levels of arsenic; as might be expected, lower operating costs are seen for an inlet of 15 ppb of arsenic than for 50 ppb.

Graver Technologies
Filtration / Separation / Purification
MetSorb™ HMRG

Effective, Low-Cost Adsorbent for Removal of Heavy Metals MetSorb HMRG and HMRP adsorbents utilize a patented material to adsorb both forms of arsenic as well as a wide range of contaminants in water. Empty bed contact times as low as 10 seconds achieve high removal efficiencies. The material affords a higher capacity and a lower level of ion interference than competitive iron and alumina-based products. MetSorb HMRG media's adsorptive capacity is 220 grams of arsenic per kilogram of HMRG adsorbent at a pH of 7. It yields 40,000 bed volumes of capacity at an inlet concentration of 40 parts per billion (ppb) of arsenic, at 1.6 minutes of empty bed contact time EBCT, and a breakthrough of 10 ppb.

Adsorbent Product Features/Benefits

• Removal of heavy metals to meet drinking water standards
• High adsorbent capacity requiring less frequent replacement
• Fast kinetics to work effectively at high flow rates
• Nonhazardous disposal as solid waste

Contaminants

Applications

• Commercial and industrial treatment units for drinking water or contaminated water
• Municipal water treatment
• Carbon blocks
• Cartridges for pitchers
• Faucet-mounted and countertop devices
• Household point of entry treatment units

Small Column Test Results	MetSorb HMRG Adsorbent Specifications
		HMRG Granular
	Appearance	White beads
	Moisture Content	<10%
	Bulk Density	0.65 grams per cc (40 lb/ft3)
	Other	Free Flowing
	Particle	-16 / +60 U.S. mesh (other sizes available)

Batch Test Data-Adsorptive Capacity MetSorb HMRG	Arsenic Treatment Capacity vs. Arsenic Inlet Levels Treatment capacity as a function of tank size.
Arsenic Removal Data - NSF 53 Testing was done under the conditions specified by the NSF Standard 53 for Arsenic. Results at a pH of 6.5 and a pH of 8.5 are shown in the graph above.	Lead Removal Column Data Lead removal by MetSorb HMRG adsorbent in column test; 30 seconds EBCT.
Lead Adsorption Isotherm Adsorption isotherms for lead between pH 5 and 7 are nearly identical.	Arsenic Adsorption Isotherm The above graph shows the adsorption isotherm for Arsenic V at pH 8.5 Isotherms for Arsenic III at pH 8.5 and for both forms of Arsenic at pH 4 are essentially identical.

Graver Technologies
Filtration / Separation / Purification
MetSorb™ HMRG 50 Micron

Effective, High Value Adsorbent for Reduction of Heavy Metals MetSorb HMRP adsorbent is a free-flowing powder designed for incorporation into pressed or extruded carbon blocks. The addition of Graver's MetSorb HMRP at relatively low levels to a carbon block design is very effective for the reduction of lead and at higher HMRP usage levels effective for reduction of arsenic to meet the requirements of NSF Standard 53. MetSorb HMRP utilizes a patented material to adsorb not only cationic lead species, but also both forms of Arsenic: Arsenic III and Arsenic V, present as (neutral) arsenite and (anionic) arsenate respectively. MetSorb HMRP will also reduce a wide range of other metal contaminants commonly present in drinking water or process water and is effective in polishing low levels of metal contaminants from industrial waste streams.

Recommended MetSorb HMRP Use

As a fine powder, the addition of MetSorb HMRP is recommended as a component of pressed or extruded carbon blocks, where heavy metal reduction is desired. In blending HMRP with carbon and poly binder components, one must assure that both the starting mechanical blend and the unfinished block produced appear homogeneous. The following guidance is provided as a starting point. The performance of each specific design should be evaluated as to reduction for the specific contaminant in question using industry-standard methodologies by qualified laboratories.

Design Parameters for Improved Performance

A nominal 10-inch carbon block, standard for most countertop and undercounter applications, will provide more overall volume and more functional media than the 2 to 2-1/2 inch blocks typically used in end-of-tap (EOT) applications. For example, a nominal 10-inch carbon blocks can easily perform for 1000 gallons or more of contaminant reduction, while the smaller EOT blocks are rated at several hundred gallons.

The larger block design also gives longer contact times (EBCT or Empty Bed Contact Time) for better contaminant reduction. For example, a nominal 10-inch block will provide an EBCT of 10-15 seconds, while a typical 2-1/2 inch EOT block gives only 3 seconds EBCT.

Devices designed for slower flow rates, e.g., 0.5 gpm (gallons per minute) versus 1.0 gpm, will provide longer contact times and better percentage contaminant reduction.

Use of higher concentrations of MetSorb HMRP will also improve heavy metal reduction efficiencies. Uniform dispersion of MetSorb HMRP in the carbon matrix is important for maximum performance.

MetSorb HMRP is thermally stable and nonorganic. It will not change characteristics, vet off-gases or odors, or lose performance when used at typical carbon block processing temperatures. MetSorb HMRP would remain thermally stable when processed under these manufacturing cycle times or, in general, kept below 575°F (300°C).

MetSorb HMRP Adsorbent Specifications

MetSorb HMRP Adsorbent Product Features/Benefits

Use of HMRP affords high capacity, excellent kinetics, and a low level of competing ion interference. HMRP's adsorbent's adsorptive capacity for lead is high, so that low concentrations (typically between 5% and 10%) can be used for nominal 10-inch carbon blocks, providing 1000 to 4000 gallons of performance. Higher concentrations of MetSorb HMRP will provide longer useful life and significantly lower effluent contaminant levels. Higher concentrations of MetSorb HMRP are also required for smaller carbon blocks, typically used for EOT devices, because of reduced total volume and short contact time.

Performance of MetSorb HMRP is generally insensitive to pH, indicating no pH adjustment of influent water is required. Devices utilizing MetSorb HMRP will provide good performance regardless of geographic area and local water pH. MetSorb HMRP is very selective for lead in the presence of hardness ions, e.g., calcium and magnesium. Because of the rapid kinetics of lead reduction, use of MetSorb HMRP in small carbon blocks can provide EOT device design with contact times as short as three seconds.

MetSorb HMRP Adsorbent is Safe

• MetSorb HMRP adsorbent is certified and listed under the NSI/NSF Standard 61 as a component of drinking water systems
• Removals of heavy metals to meet drinking water standards can be achieved without adding contaminants
• High adsorbent capacity requires less frequent cartridge handling and replacement
• MetSorb HMRP will not "avalanche" lead or other contaminants
• Spent cartridges have been determined to be nonhazardous and can typically be disposed of in a sanitary landfill as nonhazardous solid waste

Since water influent quality and contaminants can vary, the user is urged to perform their own independent verification of the nonhazardous character of this spent product containing local contaminants. In addition, some states may have disposal criteria different from Federal guidelines (TCLP).

HMRP Reduces Many Contaminants

Graver Technologies
Case History

Graver MetSorb™ Titanium-Based Media Arsenic Treatment System
Rides Roughshod Over Navajo Nation Arsenic Problem

The Problem

When the U.S. Environmental Protection Agency's new standard for the Maximum Containment Level (MCL) of arsenic was reduced from 50 ppb to 10 ppb in January 2006, water supplies in many communities across the USA - including six wells in Navajo Nation Schools located in Rough Rock, Red Rock, and Denehotso, Arizona - were faced with this problem and needed to find a solution to remedy the situation.

The Solution

Graver Technologies, LLC, a member of the Marmon Group of Companies, was chosen to bring the Navajo Nation Schools into compliance with the new standard as quickly and safely as possible. Graver's distributor, Aquacell Water Treatment, Inc., completed thorough analysis of arsenic, sulfate, pH, iron, manganese, and TDS levels in raw vs. treated water, which resulted in recommendation of Graver's MetSorb™ HMRG titanium-based media as the arsenic removal technology best suited to do the job. As the leading nationwide distributor of MetSorb™ HMRG media, Aquacell also provided the on-site, turnkey water treatment solution at each of the well sites. Since each well was situated in a remote location, a robust treatment system requiring minimal operator attention, limited backwash, and no chemical addition was of significant importance. Aquacell's highly efficient system design resulted in use of a 20 micron cartridge filter, a patented weak cation exchanger for pH reduction, and MetSorb™ HMRG titanium-based media for arsenic removal.

The Results

The six wells serving the Navajo Nation Schools now contain less than 2 µg/L vs. the 17-54 µg/L range of arsenic contained in the wells prior to treatment. The treatment process was completed quickly, caused no disruption to facility or students, and provides an ongoing means of continuously monitoring well water to ensure a safe supply of water for the schools per the data shown below:

The Results - Typical Water A

MetSorb™ HMRG (Heavy Metal Removal Granules)
Media Applications Guide

MetSorb™ HMRG by Graver Technologies is very effective at removing arsenic from water supplies when used according to the media manufacturer's recommended guidelines, which are listed below.

Typical Residential Application, Normal Downflow Service

Backwashing Information:

• For the initial backwash of a new unit, backwash at 5 gpm per square foot until backwash water runs clear
• Backwash Flow Rate: 5 gpm per square foot. To calculate the backwash flow rate, use the following formula:
  • BW flow rate (gpm) = (0.03) x (Tank diameter in inches) x (Tank diameter in inches)
• Backwash Frequency: Initial installation and recommended monthly thereafter
• Backwash Time: 5 to 10 minutes

Service Flow Rates:

• 5 to 10 gpm per square foot. To calculate the service flow rate, use the following formula:
  • Service flow rate (5 gpm) = (0.03) x (Tank diameter in inches) x (Tank diameter in inches)
  • Service flow rate (10 gpm) = (0.06) x (Tank diameter in inches) x (Tank diameter in inches)

Sampling:

• Sampling influent and effluent after initial install (to ensure everything plumbed correctly)
• In service, sample effluent every 6 months or as federal, state, and local ordinances require

Recommended Pretreatment:

• Reduce Sediment with 25 micron whole house filter (Big Blue® - type)
• Reduce Iron and Manganese levels to Iron<0.3 ppm and Manganese<0.04 ppm

Media Disposal:

• Fully loaded MetSorb™ HMRG has passed the TCLP (toxicity characteristic leaching protocol) as well as the CA WET test (California Waste Extraction Test), so it may be disposed of safely as Non-Hazardous Solid Waste. We recommend that you follow local codes and ordinances for disposal.