## 1 Introduction
The total cost of these processes was from 92.28 PLN m\({}^{-3}\) at minimum to 1632 PLN m\({}^{-3}\) at maximum, which is equivalent to 20 euros to 375 euros per m\({}^{3}\). [PERSON] et al. [34] studied the electrochemical oxidation of five azo dyesuffs using a highly boron-doped diamond (BDD) electrode in a flow reactor. They discovered that a higher degradation rate was achieved at increased current densities, with a maximum removal efficiency of 98.9%. The composition of the wastewater had a significant impact on the rate of dyestuff removal. Notably, the presence of Cl ions greatly accelerated the removal process, while the addition of NaOH inhibited it. However, the high cost associated with BDD electrode material limits their practical application on an industrial scale [35]. Microbial degradation and enzymatic treatment offer environmentally friendly alternatives, but they are often hindered by slow degradation rates and the specificity of microbial consortia [36; 37]. Thus, [PERSON] and [PERSON] [38] found that Lactobacillus casei LA1133, Lactobacillus Paracasei LA0471, and other lactic acid bacteria have the ability to modify TY under anaerobic conditions to a significant extent. The study by [PERSON] and associates confirmed that Pseudomonas aeruginosa has the ability to remove several dyes, including TY, from various industrial wastewaters. The maximum dye degradation of 72.65% was observed under aerobic conditions within 5 h at a pH of 9.12 and a temperature of 28.5 \({}^{\circ}\)C [39]. Adsorption onto activated carbon and membrane filtration effectively remove azo dyes, but these approaches can be costly and generate secondary waste [40]. The costs associated with membrane filtration treatment of wastewater from the dye industry can largely be attributed to membrane replacement expenses, which are directly related to the required membrane area and, consequently, the size of the treatment plant being utilised. utilising membrane technology presents a challenge in maintaining low costs, primarily due to the frequent need for membrane replacements associated with these applications. In industrial settings, membrane costs typically represent 10 to 20% of the total equipment expenses. For the membrane nanofiltration method, the replacement cost is between USD 30 and USD 60 per m\({}^{2}\)[41]. Electrocoagulation has gained recognition as a cost-effective and efficient alternative for azo dye removal. The process involves the in situ generation of coagulant species from sacrificial electrodes, facilitating the destabilisation and aggregation of dye molecules. The materials used as sacrificial anodes are usually different aluminium alloys, iron, steel, ductile iron, and zinc, which dissolve anodically and produce cations like Al\({}^{3+}\), Fe\({}^{2+}\), and Zn\({}^{2+}\)[42; 43; 44; 45; 46]. In aqueous solutions, these ions form the corresponding hydroxides Al(OH)\({}_{3}\), Fe(OH)\({}_{2}\), Fe(OH)\({}_{3}\), and Zn(OH)\({}_{2}\), as well as various monomeric, polymeric, and hydroxo-complexes. The specific products that form depend on the pH of the solution and the electrode potential. These hydrolysis products help destabilise contaminants in the solution, facilitating their agglomeration and enabling their separation from the solution through settling or flotation. Electrocoagulation offers several advantages over conventional treatment methods, making it an efficient and scalable solution for wastewater remediation. It effectively removes a wide range of contaminants, including dyes, heavy metals, and organic pollutants, while minimising the need for external coagulant dosing. Additionally, EC is adaptable for industrial-scale applications with minimal infrastructure modifications and generates compact sludge, which is easier to handle compared to traditional chemical coagulation [47; 48]. Despite its advantages, EC presents certain challenges, including electrode passivation and energy consumption, which require further research and optimisation.