Reagent-Free Electrolysis Purification of Aqueous Solutions from Nitrogen Compounds: Industrial Aquaculture

Abstract A study of reagent-free electrolysis purification of recirculating water supply systems for industrial aquaculture (growing catfish) was conducted. The aim was to study the efficiency of nitrogen-containing compounds (NH 4 ⁺, NO 2 ⁻, NO 3 ⁻) reduction using generators with linear and pulse waveforms. The electrochemical unit operated at a current of 30 A and a voltage of 22 V, ensuring the processing of up to 20 m 3 of water per day. The results showed that the use of a pulse power source ensures up to 40% reduction in the concentration of ammonium nitrogen and a higher efficiency of nitrite and nitrate removal compared to a linear power source. The nitrite level in water treated with a linear generator exceeded the standard by 75%, while optimal conditions were achieved with pulse treatment. The energy efficiency of the system with a pulse power source was 30% higher, with the possibility of adapting the parameters to improve reduction. After 24 h of treatment, an additional decrease in pollutant concentrations was observed due to residual denitrification. The electrochemical technology is characterized by compactness, mobility, the possibility of a high degree of automation and the absence of the need for reagents. A promising area of ​​research is the creation of adaptive power source control systems to improve energy efficiency and flexibility of the technology.