The patented technology* enables steady, direct diffusion of oxygen into an aquifer through pressurized silicone or LDPE tubing. Continuous, consistent release of oxygen into the tubing creates the ideal concentration gradient driving this passive system, without ‘bubbling off’ excess oxygen.
Emitters are ideal for the bioremediation of BTEX and MTBE using oxygen. The diffusive process provides immediate bioavailability of molecular oxygen for aerobic biodegradation enhancement, therefore no loss of the amendment gas occurs. The Waterloo Emitter can also encourage desirable abiotic reactions (pH adjustment, hydrolysis, etc.).
Waterloo Emitters are available to fit 2", 4" and 6" (50 mm, 100 mm and 150 mm) wells. They can be installed in open wells, or they can be permanently installed with sand packs in boreholes or trenches. The 51" (130 cm) long Waterloo Emitters can be installed individually or stacked one on top of another, to ensure full coverage of the contaminant plume. They are also effective in horizontal applications.
Because there is no minimum hydraulic head required, the Emitters are effective at any depth below water. When used in conjunction with packers and/or circulating pumps, the radius of influence is increased.
The Waterloo Emitter’s unique diffusive technology allows for the use of almost any chemical as an amendment to treat contaminated groundwater. The PVC frame accommodates the insertion of monitoring or sampling devices for observing groundwater conditions during the remediation process.
The Waterloo Emitter consists of silicone or polyethylene tubing coiled around a PVC frame. When a fluid is introduced into the tubing a concentration gradient is created between the inside of the tubing and the groundwater.
The Emitter works in accordance with Fick’s Law, whereby diffusion will occur until there is equilibration in chemical concentration inside and outside of the tubing. With the Emitter technology, the oxygen (or other amendment) is replenished continuously, and as groundwater continues to flow around the Emitter, equilibration never occurs. This results in continuous diffusion from the Emitter into the groundwater.
When a gas is applied to the Emitter there is a direct correlation between an increase in applied pressure and an increase in the amount of gas that will diffuse into the groundwater, however, diffusion is the only mechanism that allows the amendment to be added to the groundwater.
If an enhancement gas is to be used for remediation, a small to medium sized gas cylinder can be used. Emitter tubing is selected and pressure is set according to the amount of enhancement gas required. A single gas cylinder can be used to supply multiple Emitters connected in series.
Replenishment of the gas inside the Emitter tubing can be accommodated by periodic purging (weekly/bi-weekly), or a needle bleed valve can be used at the end of the system to allow slow, constant replenishment to occur.
Use a Drive-Point Profiler to determine the most effective areas for enhanced remediation using the Emitter by mapping/delineating the contaminant plume.
- Use Multilevel Systems to accurately delineate extent and movement of contaminants
- Focus remediation strategies more precisely using discrete monitoring systems
- Monitor remediation efforts
Use Waterloo Emitters for the controlled release of oxygen (or other amendments) for contaminated groundwater bioremediation - without bubbling
Schematic showing staged plume remediation using Waterloo Emitters, monitored by a transect of CMT or Waterloo Multilevel Systems placed down gradient.
Multiple Well Installation with a Single Gas Supply