Airwell Technology

Aeration Effects on Microorganism Activity in Groundwater Sources – Airwell is the Answer

Does the aeration provided by an Airwell installation cause extra biological activity in the water?
Yes, it does, and Airwell specifically uses such biological activity to remove many of the targeted contaminants from the water source.

It should be noted that with Airwell, however, the enhanced biological action gets seduced out of the well volume itself and into the local aquifer. Airwell’s recycling of aerated water all the way to the bottom of the well allows dissolved oxygen to diffuse out into the aquifer and most of the troublesome organisms follow this oxygen trail out into the aquifer. By this means, any prior “iron bacteria’ activity plus most any other biofouling becomes quite minimized in the well itself.

For example, the oxidation of iron and sulphide contaminants towards removal is much assisted biologically, while manganese oxidation is solely catalyzed by microorganisms. Mineral precipitations as caused by oxidations in the aquifer, allow such contaminants to be filtered out locally before the water actually reaches the well. Keeping these contaminant deposits out of the well contents further lessens any well fouling.

Methane provides an exception to the rule in that while dissolved under pressure, biological organisms find it too unretainable to use effectively as a nutrient. With its removal in the aquifer being so limited, this gas really separates from the water mainly in the upper zone of the Airwell aeration tube where the freed methane mixes with the injected air to create quite intense biofouling conditions. There, however, the tube’s aeration section is kept clear of plugging growths by its special internal features until the methane and air mixture is lifted clear of the tube and its surrounding water.

Waters with elevated organic food, as measured by a TOC (Total Organic Carbon) test plus methane, are the hardest to treat by any technology, and will usually show biological evidences of problems even before treatment. In absence of iron contaminant, the Airwell can handle 5 and even 10 mg/L TOC (as C); but, when precipitable iron is present, the treatable TOC may drop to the 2 to 3 mg/L range. Precipitating iron concentrates organic matter on its surfaces for the bacteria to consume more oxygen, which when exhausted, can allow restoration of aquifer iron solubility to enter the well.

For this reason, Airwell personnel may check the raw water TOC to assure success for any iron-removing installation.

How The Airwell Treatment Improves Water Quality

How The Airwell Treatment Improves Water Quality
The Airwell, system is designed to treat residential groundwater supplies coming from aquifer sources devoid of prior access to atmospheric oxygen. Unable to vent to the atmosphere, gases, such as methane, radon, and other volatiles may accumulate under pressure in such water. Additionally, without contact to the oxygen of the atmosphere, excess oxidizable mineral elements such as iron, manganese, and sulphide may develop towards causing staining and plugging deposits in the user’s water system once air access does occur.

The Airwell installation seeks to restore air access to the water for remedying its prior restraints. Basically, a steady source of air is provided in an aeration tube that extends all the way to the bottom of the well. This air injection lifts the water column in the tube to pour an aerated flow of water onto the top of the water level of the well itself. As water is drawn from the bottom of the well and returned onto the top, in a few hours all the water in the well will usually have passed through the aeration cycle several times.

The result is that the injected air will have stripped previously trapped gases out of the water and will have done so at the quite depressurized conditions at the top of the well.

Meanwhile, the dissolved oxygen in the aerated water as delivered to the bottom of the well with up to 10 mg/L of oxygen ends up opposite to the aquifer zone from which the well obtains its water. During quiescent, non-pumping intervals, such as with a nighttime residential cycle, this dissolved oxygen diffuses out into the aquifer to oxidize contaminants before they get access to the well itself. Oxidized contaminants are thus filtered within the aquifer itself, on the basis that water withdrawals at any one time do not exceed several hundred gallons.

Now, aeration can be considered one of the simplest, chemical-free procedures that one can imagine; but, any standard aeration of well waters usually plugs severely in a manner of weeks, unless the patented Airwell techniques are applied. Airwell systems entail no over-dosable chemicals and no inconvenient home treatment processes. The water is treated the way that nature would have, if air access to the aquifer would have been available.

Airwell Application to Suppress Excess Iron in Residential Well Supplies

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Airwell Application to Suppress Excess Iron in Residential Well Supplies
Written by F.J. Dart, P.Eng.
Iron, though an essential mineral for most life-forms on earth, can occur in groundwater supplies at levels troublesome towards water supply systems. Where aquifer sources lack access to atmospheric oxygen, contacted iron-bearing minerals may often degrade, usually biologically, to release iron in its soluble divalent, ferrous ion (Fe2+) form to the water. However, when exposed to air, this soluble iron can be readily be oxidized to a far less soluble trivalent, ferric form (Fe3+) that can drop out of solution as a rusty brown precipitate. Waters with a limited amount of iron from 0.3 to 0.5 mg/L Fe may just stain contacted surfaces; but, where larger concentrations occur, essential plumbing systems may become obstructed by heavier deposits.

Water aeration, such as provided by an Airwell installation, quickly oxidizes the water’s iron content towards precipitation. While the initial volume of water receiving aeration in the well may have iron content to settle to the well bottom, subsequent inputs from the aquifer will have its iron content removed before it enters the well.

Airwell in recycling water from the well bottom via its air-lift pumping procedure cycles aerated water back down the well to the aquifer’s interface region. Once there, up to 10 mg/L of dissolved oxygen in this water diffuses out into the aquifer to create a local zone of aerobic filtration conditions around the well area that will remove the iron being air-oxidized. Additionally, earlier ferric precipitates as retained in the aquifer will also capture further soluble iron heading towards the well. Soluble ferrous ion on being captured by ferric ion silts forms a magnetic iron oxide with its similar insolubility.

Thus, in domestic use wells, the dissolved oxygen that seeps out into the local aquifer during unused night-time periods, builds up an underground filtration capacity to cleanse several hundred gallons of oxygenated water free of its iron content for subsequent day use. Each night, this capacity gets regenerated for use on each following day.

Certain more difficult iron control situations, often dubbed “iron bacteria problems”, are occasionally encountered as fueled by elevated organic contaminants being absorbed onto iron precipitates wherever they occur. When concentrated upon depositing iron silts, these formerly less attainable nutrients become readily available to sponsor tenacious biofouling. What intensifies such biofouling is that the oxidized iron itself can also be used by the microorganisms to consume the organic food – a process by which the iron is reduced back to its soluble form – only to reprecipitate and cycle even more organic nutrients back into the problem. High organic content can, thus, cause problems for most every filtration process.

It is useful, therefore, to test the Total Organic Carbon (TOC) in waters undergoing filtration for the removal of iron. TOC’s in excess of 5 mg/L as C in the presence of iron precipitates can prove problematic. In absence of such iron, TOC levels are seldom so significant.

Airwell Application For Remedying Excess Radon in Residential Well Source Water

Ariwell Application For Remedying Excess Radon in Residential Well Source Water
Written by F.J. Dart, P.Eng.
Radon is a chemically inert gas created during the radioactive breakdown of natural, but randomly occurring thorium and uranium minerals. Specifically, isotopes of radium as formed during the number of intermediate steps in their radioactive decay processes, give the direct release of the radon, which as a volatile element, partially escapes its rocky environment for entry into local groundwater. For groundwater sources trapped between rock layers and lacking any venting of gas to the atmosphere, the concentrations of the radon can build up to what health officials have determined to be potentially hazardous levels. Inhalation of the trace gas during confined space uses of the water, such as in showering, is considered to be the chief risk as opposed to only drinking the supply.

The hazard of the radon is that it, too, is a radioactive substance actively emitting nuclear radiation during its decay half-life of 3.8 days. Though radon itself would not linger in lung tissues, the radon that radioactively decays while present in one’s lungs, produces daughter isotope elements that can affix themselves to contacted surfaces. It is the continued radioactivity from these daughter isotopes that would sponsor deleterious radiation damage.

While no mandatory limits has been established for radon in private well systems, the USEPA has strongly advised that measures to remove radon be implemented for those supplies exceeding 300 picocuries per litre (300 pCi/L) or 11 Bequerels per litre (11 Bq/L). [One Bequerel = one atomic disintegration per second.

Radon is readily removed by aeration processes that can strip hazardous levels of the gas from the water. The Airwell system also uses aeration, but with patented advantages. An Airwell installation uses a draft tube reaching all the way to the bottom of the well to draw confined bottom water up through an upper aeration section that strips the radon from the supply and returns treated water on top until all the volume in the water column has been quite cleansed by a continuous recycling. For example, with the air injection lifting some 3 gpm from the well bottom, a six-inch diameter well containing 120 Imperial gallons (145 US gallons) within a 100 feet, would have had its water column pass through the aeration effect every 40 minutes. Such a well, idled between midnight and 6 am, would have had its water content scrubbed and rescrubbed of volatile contaminants about 9 times in that period.

Additionally, Airwell’s circulation of aerated water back down to the well bottom tends to diffuse the water’s dissolved oxygen out into local zones of the aquifer to restrict the entry of dissolved iron and sulphide contaminants from even entering the well volume itself. Airwell also is effective at removing excess methane and other volatile contaminants, should any of these problems be additionally present.

Airwell Application for Remedying Excess Manganese in Residential Groundwater Sources

Airwell For Removing Excess Methane Gas From Residential Well Supplies
Written by F.J. Dart, P.Eng.
Methane, as the chief fuel component of commercial natural gas, may occasionally permeate confined groundwater flows passing by underground sources of this gas. Methane arises mainly from the airless decomposition of bulk deposits of buried organic matter; but evidence of deeper sources, also, appears to suggest that invading water attacking carbon-rich minerals (i.e. aluminum carbide, Al4C3, ) as derived from earth’s hot magma zone may contribute an additional primordial source.

Major amounts of methane in a well may vapor-lock well pump operation, cause annoying spouting at household taps, and / or release much flammable gas as a potential explosion hazard in confined spaces. More minor amounts can produce cloudy tap water that clears as fine bubbles from the bottom up or cause biofouling problems against other water treatment operations, such as in filtration units. One sensitive indicator for trace methane presence can usually be a translucent streak of gelatinous (sometimes rust-stained) slime along the inside fill rim of the resident’s toilet tank.

Nuisance levels start when the gas can form methane bubbles on being released from either its water depth or pump pressures. This corresponds to about 3 litres per cubic meter (at STP*) as mentioned in Ontario’s Drinking Water Standards while taking pressure-sealed water samples for laboratory submission.

Airwell’s patented aeration system is highly effective at expelling methane (and other volatiles) from the well’s water column without succumbing to heavy biofouling that most air aeration processes would normally encounter. Water recirculating from the well bottom through the aeration-lift tube and back down may do so up to 8 or 9 times during a nightly unused period of, say, 6 hours. As degassed water circulates back down to the aquifer level, extra methane may diffuse out of the local aquifer into the well itself for some extra advance removal. Provided the intervals of well use are not excessively prolonged, problematic levels of methane can usually be averted.

* STP: Standard Temperature & Pressure for measuring gas = 20oC @ 1 Atm (101 kilopascals)

 

Airwell For Removing Excess Methane Gas From Residential Well Supplies

Airewell Appication for Remedying Excess Manganese in Residential Groundwater Sources
Written by F.J. Dart, P.Eng.
Excess manganese in groundwater parallels that of excess iron in depositing brown stain precipitates upon air-exposed fixtures. Though often matching those of iron, stains from manganese can range much darker and even black, and may form from water with as little as 0.05 mg/L Mn. Bedded deposits of decaying pond weeds from either current or former bog sites are often the strongest sources of leached manganese to nearby wells. Local rocks biologically weathered under vegetative cover will also contribute dissolved manganese typically as the divalent manganous ion (Mn2+) form.

But manganese differs from iron in remaining relatively soluble in sunlight surface water. The oxidized, normally insoluble manganic (Mn4+) is readily dissolved by the hydrogen peroxide as formed (several mg/L daily) by solar ultraviolet light upon open water. In fact, applying an acidified peroxide solution (i.e. a 50-50 mix of vinegar and drugstore peroxide) can quickly distinguish a manganese stain from an iron one. An established iron stain will resist being dissolved, but a manganese one will fade into a colorless solution.

Groundwater manganese rarely exceeds 1 mg/L Mn; but, exceptions have been noted with over 10 mg/L in some Alaskan environments. Manganese, as with iron, is not regulated as a health concern; but, gets recommended to have a 0.05 mg/L limit to avoid potential staining problems. Actually, some trace manganese in one’s diet is advised for optimum personal health.

All procedures for an oxidative removal of manganese end up being more complicated than those for iron. Manganese, being more resistant to direct air oxidation and binding more strongly to accompanying natural organics, may separate into proportions proving either removable and not so removable by any selected procedure. Some residual trace manganese often remains after treatment.

In the case of an Airwell application, dissolved atmospheric oxygen gets circulated continuously back down to the bottom of the well for diffusing out into the aquifer. Here, an effective biological oxidation of the manganese does the main job of oxidizing all that proportion of the manganese that can be readily oxidized to leave it behind in the aquifer rather than allowing it to enter the well.

While partial removals of manganese occasionally occur with almost every removal process, the Airwell procedure essentially solves post-treatment staining by removing that specific portion of the manganese able later to oxidize and form deposits within the user’s water system.

Airwell Application for Remedying Excess Sulphide in Residential Well Supplies

Airwell Application for Remedying Excess Sulphide in Residential Well Supplies
Written by F.J. Dart, P.Eng.
Sulphides, as easily detected by their distinctive “rotten egg” odour and tendency to blacken household silverware, may occur in water environments lacking direct contact with atmospheric oxygen. Most commonly, sulphides are formed biologically by anaerobic bacteria using carbonaceous nutrients, such as natural hydrocarbons or other sources of sulphides may include natural volcanic activity and even local slag deposits from metallurgical industries.

While strong levels of volatile sulphides in air can be quite toxic, the levels of sulphide (i.e. 0.05 to 20 mg/L as H2S) that may range in affected groundwaters, are considered by most regulators as just “objectionable” without a specified limit. In fact, ”sulphurous spa waters” are commonly sought after for remedying certain allergic and immune system health issues.

Water-borne sulphide, however, becomes problematic when its contact to air commences its chemical oxidations. Soluble sulphide can first produce “free elemental sulphur” whose colloidal precipitates may significantly plug water system facilities.

Also, there’s sulphide’s conversion of exposed metal surfaces into unstable sulphide layers completely disintegrable by subsequent air contact into free sulphur solids and soluble metal releases. Free sulphur suspensions as resultant from initial oxidation can be further oxidized by biological organisms to fully soluble sulphates.

This oxidation to sulphates can specifically develop acidic conditions upon a well’s wet surfaces at and above a well’s normal static level. Here, air oxidations of evolving sulphide fumes may become oxidized to a series of sulphur-based acids which in absence of sufficient dilution water can create corrosive conditions. Metal well casings at such locations may come under local acid attack to introduce an additional iron contamination to the water.

When examining a well for sulphide content, it can be useful to determine whether the sulphide comes from the aquifer itself or is actually being created by nutrient-sponsored biological activity in the well’s water column. Comparing immediate and extended pumping samples for shifting sulphide levels can distinguish between these sources.

Airwell quite excels at controlling sulphides. Conditions for biological breakdown of sulphates to sulphides in the well are completely dispelled by the air-sourced oxygen distributed throughout the well column; and, as for aquifer-sourced sulphides, up to an impressive 16 mg/L H2S has been treated successfully. The circulation of water lifted by aeration from the bottom of the well and back down diffuses dissolved oxygen out into the aquifer and ultimately prevents sulphides from even entering the well. Former sulphide attack to well hardware, thus, becomes eradicated upon this sulphide exclusion. Residual air content in the treated water may also inhibit sulphide formation developing in customers’ hot water tanks.

Treatment response for sulphides lower than 2 mg/L H2S is quite immediate, while higher sulphide levels may induce a hazy to milky water for a day or two until the aquifer fully bars all sulphide entry into the well. Where there had been sulphides formerly attacking metallic well components, temporary spikes in iron levels might be noted with decreasing occurrence as former iron sulphide deposits become gradually dissolved away.

airwell radon system

How the Airwell System Works

• A pipe with an aeration section is inserted into the well bore, down to the bottom of the well.

• Pressurized air is fed into this pipe on an ongoing basis. This causes the water from the bottom of the well to be air-lifted to the top of the pipe.

• Recirculating the water in this manner oxidizes the water contaminants in the well, actually penetrating back into the aquifer.

• Test results show that the Airwell system quickly and reliably removes contaminants.

How The Airwell Treatment Improves Water Quality

The Airwell, system is designed to treat residential groundwater supplies coming from aquifer sources devoid of prior access to atmospheric oxygen. Unable to vent to the atmosphere, gases, such as methane, radon, and other volatiles may accumulate under pressure in such water. Additionally, without contact to the oxygen of the atmosphere, excess oxidizable mineral elements such as iron, manganese, and sulphide may develop towards causing staining and plugging deposits in the user’s water system once air access does occur.

The Airwell installation seeks to restore air access to the water for remedying its prior restraints. Basically, a steady source of air is provided in an aeration tube that extends all the way to the bottom of the well. This air injection lifts the water column in the tube to pour an aerated flow of water onto the top of the water level of the well itself. As water is drawn from the bottom of the well and returned onto the top, in a few hours all the water in the well will usually have passed through the aeration cycle several times.

The result is that the injected air will have stripped previously trapped gases out of the water and will have done so at the quite depressurized conditions at the top of the well.

Meanwhile, the dissolved oxygen in the aerated water as delivered to the bottom of the well with up to 10 mg/L of oxygen ends up opposite to the aquifer zone from which the well obtains its water. During quiescent, non-pumping intervals, such as with a nighttime residential cycle, this dissolved oxygen diffuses out into the aquifer to oxidize contaminants before they get access to the well itself. Oxidized contaminants are thus filtered within the aquifer itself, on the basis that water withdrawals at any one time do not exceed several hundred gallons.

Now, aeration can be considered one of the simplest, chemical-free procedures that one can imagine; but, any standard aeration of well waters usually plugs severely in a manner of weeks, unless the patented Airwell techniques are applied. Airwell systems entail no over-dosable chemicals and no inconvenient home treatment processes. The water is treated the way that nature would have, if air access to the aquifer would have been available.