Adaptive microalgae disinfection system as the basis of a new technological approach to closed water supply installations

Abstract

Modern conditions of industrial fish farming are accompanied by the uncontrolled influence of natural or man-made factors that affect water quality, which in turn affects the quality of products. One of the specific factors is the negative effect of microalgae and their toxins on water quality indicators. There is a need to create mechanisms to eliminate the factors of microalgae development and the manifestation of their toxins, if possible - the destruction of the toxins themselves. Industrial farms must have a system that can eliminate in a preventive automatic mode the negative effect of microalgae on the aquatic environment, while such a system must be safe for the environment and humans. Substantiation of technological and constructive solutions for the microalgae disinfection system operation using an adaptive approach to the structure in general, as well as individual blocks and units based on pulsed electrochemical methods as the main factors influencing water condition. The use of electrolytic methods of microalgae neutralization enables us to simultaneously realize the mechanism of change of toxic effect of aquatic organisms' urine when it is accumulating into nontoxic. This is done through the transformation, oxidation, and reduction of its aqueous solutions, which provides a change in the solution properties to optimal for plant nutrition. The use of electrolytic transformation methods is a new approach to the innovative technology of closed water supply systems (CWSS) for fisheries or greenhouse complexes, which can perform one, two, or more important tasks in a single technological cycle. The first one is the disinfection of hazardous bioagents as well as the destruction and removal of microalgae. The second one is the controlled transformation of the urine of aquatic organisms into a nutrient solution with the necessary ionic form for use by the plant root system. The third one is the synthesis and production of important components such as oxygen and hydrogen. The fourth one is the collection and subsequent use of the condensed fraction of microalgae. The main control parameter of water is light transmission - as a simplified, generalized indicator of the presence of microalgae in the aquatic environment. The system uses an effective process of destructive action on microalgae and their toxins - pulsed load current of electrodes with changes in its parameters and shape to prepare the water structure for better current effect due to cavitation blocks, which also destructively affect microalgae and toxins.  When changing light transmission and pH of the working solution, the parameters of the pulsed load current are also changed by the adaptive power supply source to the most efficient. The proposed solution can be improved by using known developments used for better water purification in adaptive water purification systems. One of the promising areas is the selection and direction of microalgae and the condensed fraction of aquatic organisms at the same time to the adaptive biogas system (ABS) to obtain quality organic fertilizers and biogas. Another area is creating adaptive control systems for water parameters for hydroponics and aquaponics systems. An important extra factor of the new technological approach is the use of an electrolyzer with an insoluble anode and oxygen membrane that can be injected into the aquatic environment with aquatic organisms, as well as hydrogen for use as a source of power or heat.