What is a Protein Extractor?
A protein extractor is a device that concentrates and removes dissolved material from water by floating it to the surface via an accumulation of air bubbles. It basically consists of a tube (the contact column) for the concentration of bubbles, an aeration device (e.g. air stone, venturi) a water inlet and outlet, and a removable collection bowl. Some units may add additional features, but the basic design is the same.
The name “protein extractor” is essentially misleading. A more appropriate name is “foam fractionator,” due to the fact that the bubbles concentrations (foam) serve to separate (fractionate) dissolved material from the water. Most of the material, termed DOC (Dissolved Organic Carbon) by scientists, is produced by the biodegrading activity of certain bacteria, but some is released by algae and other organisms as part of their normal bodily function. Because the DOC is dissolved in the water, they cannot be removed by traditional mechanical filtration methods.
Why use a Protein Extractor?
A foam fractionator removes the DOC that a traditional mechanical filter does not. The accumulation of DOC in water, among other things, inhibits the nitrifying bacteria and increases the biochemical oxygen demand (BOD a way of measuring water pollution), thus lowering water quality. Water becomes discoloured and smells foul. Furthermore, some types of DOC can be degraded by bacteria in the water,
via a process called Mineralization. Heterotrophic bacteria convert DOC into toxic substances such as ammonia and carbon dioxide while consuming vital oxygen in the process.
How does a Protein Extractor Work?
The two keys to effective protein extracting (or foam fractionating) are air bubbles and surfactants. DOC are surfactants-compounds whose surface is defined as “active.” This means that when a surfactant compound is in water, its non-polar end, labelled hydrophobic or “water hating,” seeks the surface, in the air. Normally, the only “air surface” in a pond is the surface of the water. However, if bubbles are added to the water, more air surface is created. More air surface means more surfactants (DOC) are attracted and removed.
Smaller bubbles have more surface area than larger ones. Also, the longer the bubbles stay in the water, the longer their contact time with the surfactant. Bubble size and contact time determine how effective and how fast an extractor will work.
Protein extractors take advantage of these physical properties by producing a large amount of bubbles in a controlled space–the contact column. This serves to concentrate the bubbles and the DOC. As the bubbles in the column rise, the surfactants (DOC) attach o the surface of the bubbles so that its hydrophobic end is “inside” and in contact with the air. The bubble carries the DOC to the water surface, where it forms foam.
The air-preferring DOC stays at the surface rather than re-dissolve into the pond water.
This process is repeated thousands of times a minute and a large amount of foam can be generated. The foam grows over time, is collected in a bowl or other such vessel, and is to be removed at regular intervals. While there is considerably more physics involved in trying to produce the right bubble size and in the determination of other factors as well, this is the basic operative mechanism involved in protein extraction. The goal of any good extraction is to produce a great number of small bubbles in the contact column.
With the improved technology of the Aqua-Sure Protein Extractor, it is possible to remove harmful protein compounds from freshwater
It is recommended pumps between 3600-4500lts to be used with sufficient head to power a venturi. If a larger output pump is used this may cause the unit to overflow. If this occurs reduce the output from your pump with an inline valve.
The Pond protein Extractor offers a good specification and value for money relative to competitors products and will appeal to those suffering from foam on the surface of the pond (through excess protein or dissolved organic compounds). It will also appeal to those committed to obtaining the ultimate in water quality. The unit will cater for ponds up to 8,000 gallons (36,000 litres) and is 600mm dia x 350mm high.
Minimum pump requirement 4,500 LPH. Pipe inlet size 40mm (1.5”) – outlet 50mm (2”). With no filter mediums to keep clean maintenance of the device can be fairly described as almost non-existent.
The basics of the devices operation is that pumped water (via a dedicated pump) passes under pressure through a venturi unit, where the input of air creates a mass of air bubbles which attract and contain contaminants within the water. These bubbles burst within the central inner chamber of the tank and the extracted contaminants are passed through gravity along a pipe to the 320mm dia external waste catchment bowl. The remaining water in the tank is returned to the pond. Processes of this type cannot be classified as mechanical or biological when they are neither, however they do contribute to reducing nitrite levels.
Many pond keepers believe that their current water quality is exemplary, and become amazed when they establish just how much dirty waste matter can be extracted from their ponds upon installing a Pond Protein Extractor (protein skimmer) type device. Beyond general contaminants, colourants are also converted into waste, and as an end result, water clarity and sparkle is visually improved with a more healthy environment being created.
To cater for various pump flow rates two control valves are provided to adjust both the water level within the tank and the amount of flow generating the oxygen input.
With no two ponds being the same it is impossible to state how much waste can be extracted from any pond. Likewise, there are no cast-iron rules as to using a Pond Protein Extractor properly. Some pond keepers will find it necessary to have the device running 365 days a year, whilst others will obtain adequate success in only using the device for a few days each week after an initial dirty running period.
The importance of having good oxygen saturation levels in Koi ponds is vital for the health of the fish, and of great importance to sustaining the beneficial biological bacteria which colonise within conventional filtration system mediums. This can be achieved by numerous techniques including airstones, or conventional venturi units, however not everyone wishes to having their ponds resemble a witches cauldron, and it is in this area where the Pond Protein Extractor offers a great bonus by pumping oxygen into the water.
The 2 control valves should be adjusted so that a slow drip pattern is seen going into the external waste bowl. Heavy rain, water changes and feeding the fish will have a temporary effect on reducing the drip flow rate (perhaps to nothing), however, no further adjustment should be made, and the system should be left for normality to return.
To reduce surface agitation and noise the return pipe to the pond can if required discharge via a bend and short vertical drop with the bottom of the pipe drop set 30mm below the pond surface. All pipework should be 50mm in diameter.
In the event of using medications in the pond, it is advisable to adjust the Pond Protein Extractor so that its extract abilities are terminated, however, under such circumstances, the device should be left running due to its production of oxygen.