Overview of the Eget Liber Process

In the first stage we apply ultraviolet light at 254 nm (UV-C), nano-air bubbles (aeration), and ultrasonic excitation at about 28 kHz to the water and the algae and cyanobacteria it may contain. This stage is intended to weaken them before the second stage: the ultrasound breaks up the gas vesicles that keep cyanobacteria afloat, the nanobubbles change their buoyancy and carry them toward the UV-C light, and the UV-C damages their DNA, impairing their ability to reproduce.

In the second stage, we treat the effluent from the first stage with ozone (O₃), which is intended to mitigate harmful algae and to degrade the toxins that they produce. Ozone is a well-known, highly reactive form of oxygen: a powerful oxidant that must be contained, which is why the third stage exists.

In the third stage we treat the effluent from the second stage with another dose of UV-C. UV-C light breaks down residual ozone, releasing oxygen (O₂); in water, the same reaction also produces hydroxyl radicals, among the most reactive oxidants known. This combination of UV and ozone is a recognized advanced oxidation process (“AOP”), described in the scientific literature. The radicals react rapidly with organic matter, including algal toxins, so the third stage both destroys leftover ozone and adds a further oxidation step. We specifically included the third stage to destroy residual ozone before the water is returned to the body of water.

We have provided samples of treated and raw (untreated) water to scientists at the laboratory of Prof. Gregory Boyer at State University of New York College of Environmental Science and Forestry (SUNY-ESF) who have analyzed those samples for algae present, for the growth trajectory of the algae and cyanobacteria over time, and for the toxin concentrations over time. In tests reported at the Eastern Analytical Symposium on November 15, 2021, the combined treatment reduced the cyanobacteria and lowered the concentration of microcystins, toxins that cyanobacteria produce, compared with untreated controls, both in laboratory cultures and in water from Lake Neatahwanta, New York. The results are reported in “Preliminary Treatments to Combat cHABs Using UV-C, Sonication, Ozone, and Aeration on Cyanobacterial Cultures and Lake Water,” by Dominique Derminio, Jason Dean, Andrew Bishuk, and Gregory Boyer (Keuka College, Eget Liber, Inc., and SUNY-ESF).

We have built our reactor system to operate using digital control. Therefore, we can modify the intensity of the components of the reaction (UV, nanobubbles, sonication, ozone) as may be needed or advisable, within the capacity of a given reactor. This allows us to tailor the parameters of a specific process in response to what is present in the water to be treated.

That is also why the process can be described only in general terms. A “recipe” for treating algae, like the recipe for any process whose ingredients can change in amount or in character, can only be stated in generalities. The Science page discusses this further.

For a reactor carried by a vessel, we can also control the velocity of the vessel. Since the flow through the reactor is driven by the speed of the boat relative to the body of water, we can control the rate of flow of the water through the reactor, or equivalently, the residence time of the water in the reactor. Therefore, we have control over the duration of the stages of the process by controlling the vessel velocity. For stationary reactors we expect that the residence time will be controlled by the velocity of the water that is pumped through the reactor.