Follow the links below to find answers for Frequently Asked
Questions about Aqua Technologies unique product, ET-1.
What is ET-1 Activated Clay?
ET-1 Activated Clay is a granular adsorbent material that can be used
to remove oil, grease, petroleum hydrocarbons and other organic compounds
from wastewater. It is commonly used with a subsequent stage of granular
activated carbon to provide high-quality wastewater treatment. ET-1 Activated
Clay is manufactured from sodium bentonite clay that is chemically modified
to make it hydrophobic (water repelling) and organophilic (oil attracting).
The specific formulation is proprietary.
How does it work?
It is normally manufactured as a granular material to be used in still-bed
adsorption vessels. It removes hydrocarbon contaminants by adsorption
as the wastewater passes through the media-filled vessels.
What are its indicated uses?
ET-1 Activated Clay is most effective on petroleum oils including crude
oil, petroleum lubricants, and fuels including the petroleum portions
of gasoline, diesel fuel, and fuel oil. These contaminants are commonly
identified in wastewater discharge permits by the EPA as standard Oil
& Grease or Total Petroleum Hydrocarbon. The usage of ET-1 Activated
Clay to remove specific organic compounds from wastewater other than generic
Oil and Grease or Total Petroleum Hydrocarbons should be evaluated on
a case-by-case basis.
What uses are not recommended?
ET-1 Activated Clay is not recommended for use in streams containing high
amounts of synthetic lubricants or streams containing a high concentration
of surfactants or soaps. Contact us at (888)-456-0008 for stream-specific
How well does it work?
When ET-1 Activated Clay is used according to recommendations, it is able
to remove EPA Oil and Grease or Total Petroleum Hydrocarbons to concentrations
near or below detection limits. This removal efficiency has been documented
in influent concentrations from 10 mg./L to 200,000 mg./L hydrocarbons.
It virtually assures the facility owner that wastewater will meet discharge
permit requirements for these two standards.
What are the physical properties of ET-1 Activated Clay?
- Bulk Density 42 to 50 lbs. per cubic foot depending on grain size.
- Loading Factor (Design) 0.5 gm. Hydrocarbon per gram ET-1
- Loading Factor (Ultimate) 0.7 gm. Hydrocarbon per gram ET-1
- Hydraulic Conductivity (Pressure Drop Through Media Bed) T.B.D.
- Compressive Strength (Crush Resistance) T.B.D.
What is the recommended contact time?
Each vessel should allow a minimum of 3 minutes of contact time between
the adsorbent medium and the wastewater. For those persons with a background
in granular activated carbon treatment, the recommended contact time is
equivalent to an Hourly Space Velocity (H.S.V.) of 5.5, which will be
relatively high in their experience. H.S.V. is defined as the flow rate
equivalent to the number of vessel volumes per hour.
What are the recommended vessel dimensions?
The vessel volume required to achieve a 3-minute contact time is calculated
by multiplying the wastewater flow rate (volume per minute) by 60. This
calculation assumes a 33% porosity (water filled volume) within the bulk
medium. [If the H.S.V. is used, the required vessel volume will be flow
rate (volume per hour) divided by 5.5.] - (Note: 1)
The diameter of a cylindrical vessel is calculated to provide
a recommended superficial flow rate through the medium of 2 g.p.m. per
square-foot of area. - (Note: 2)
The height of a cylindrical vessel is calculated by dividing the required
volume by the cross-sectional area.
Note 1: In actual practice, one should follow published
Note 2: Exceeding the recommended superficial flow rate through a vessel
can create excessive pressure drop in down-flow vessels. In upflow vessels,
a higher flow rate can cause media upset and abrasion due to turbulent
How should I prepare the media?
The ET-1 Activated Clay should be wetted before use. Wetting allows water
to be drawn into the pores of each grain by capillary action and prepares
the clay surfaces to adsorb contaminants. One acceptable method is spraying
water into the vessel with a hose as the ET-1 Activated Clay is poured
in. The water helps consolidate the media bed and helps prevent channeling.
It also flushes fines that may have been generated during shipping and
handling. Sixty minutes will permit the media to adequately saturate.
What limits should be observed for proper usage of ET-1?
Wastewater temperature must be kept below 140º F.
The pH should be kept between 6.0 and 8.0 in order to reduce the tendency
of dispersed oil to form stable emulsions. (Note: pH range does not affect
the media but can affect ability of the waste stream to allow oils to
naturally separate from the water.)
Wastewater Salinity: ET-1 is not affected by salinity.
Wastewater must not contain high concentrations (approximately >25ppm)
of free oxidizers including chlorine gas, hypoclorite, peroxide, or permanganate
because they will possibly degrade the ET-1 Activated Clay.
What are my disposal options?
ET-1 should be handled and disposed of in accordance with the laws of
the state in which it is used and all applicable federal law. Should you
need assistance in finding proper disposal options, contact our manufacturing
division at 800-839-0565. We will be glad to help.
Depending on the nature of the contaminant and local regulations,
spent ET-1 may be classified as a non-hazardous solid waste. If lab results
confirm this determination, the spent material might be landfilled, landfarmed,
composted, or used as a granular material fill.
Depending on the fuel value of the material adsorbed by
the product, spent ET-1 may also be blended into boiler fuel for energy
ET-1 cannot be thermally regenerated in the manner of activated
carbon, but methods of bio-remediation are being investigated.
Are there alternative treatment processes?
Some contaminants that resist adsorption by the still-bed method can be
removed in a high-shear process. This process is designed to treat compound
waste streams that contain a mixture of organic and inorganic compounds.
This method includes mixing fine (40-100 mesh) ET-1 with the water as
well as other materials. The exact materials and steps used in the process
are proprietary and will be revealed on a case by case basis.
Are there any non-wastewater uses for ET-1?
ET-1 is an excellent adsorbent for spills of petroleum lubricants and
fuels. The product can also be used as a tool and parts cleaner. Other
commercial clay products marketed for this purpose are absorbents (absorption
works like a sponge) that can release the contaminants.
Is ET-1 safe for my employees to handle and use?
ET-1 is very safe to handle and use. Its use requires only that some precautions
be used as would be required when handling other potential dust producing
materials. Please refer to the Material
Safety Data Sheet for ET-1.