# A Sustainable Electrochemical-Based Solution for Removing Acetamiprid from Water
## 3 Results
### Influence of Different \(j\) on the EO of ACT
This follows the results observed in Figure 2, as the oxygen evolution potential of the non-active anodes has a potential greater than that presented by active electrodes (see Figure 2). Thus, the evolution of oxygen is slower at this type of electrode, and consequently, the production of hydroxyl radicals is significantly favored, which accelerates the oxidation process [17; 18; 23; 35]. Nevertheless, it is important to remark that the use of BDD as an anode and the significative concentration of sulfate ions in solution, due to the electrolyte, promotes the electrosynthesis of sulfate-based oxidants (ion sulfate radical (Equation (5)) and persulfate (Equations (6) and (7)) [36]) that participate in the indirect oxidation of the organic compounds [14; 37; 38; 39; 40]. \[\mathrm{SO_{4}^{2-}\to SO_{4}^{\bullet-}+e^{-}} \tag{5}\]  
Figure 3: Comparison of the influence of \(j\) on the EO of 30 mg L\({}^{-1}\) of ACT using DSA anode as a function of electrolysis time. The participation of sulfate-based oxidants plays a key role in the efficient degradation of ACT at all \(j\) values because no other absorption bands appear in the final phase of the electrochemical treatment (Figure 4). Then, no absorptive by-products were generated from BDD electrolysis, contrary to the behavior at the Ti/TiO\({}_{2}\)-RuO\({}_{2}\)-IrO\({}_{2}\) anode (see Figure 3). From an environmental point of view, some physical-chemical parameters were measured before and after the EO of synthetic effluents (Table 1). DFZ values (Equation (1)) were also estimated [21] to establish the wastewater quality of the real effluent (Table 1), and the result showed that the treated effluent could be reused (e.g., for irrigation or washing) when the BDD anode was used. Nevertheless, the data obtained at the DSA electrode demonstrated that the treatment could still be improved. Thus, these results demonstrated that higher decontamination of the effluent was achieved when the degradation pathway was guided by hydroxyl radicals and sulfate-based oxidizing species in a sulfate-mediated solution [9; 21], but the organic matter removal should be also determined. Therefore, the determination of COD was carried out at the end of the electrolysis using both materials. Analyzing the data obtained at the end of electrolysis using both materials (Table 1), it is evident that the EO process favored the elimination of organic matter dissolved (ACT and by-products) in the synthetic effluent. However, high oxidation efficacy was demonstrated by the BDD anode. In the case of salinity and  
Figure 4: Absorption spectra as a function of electrolysis time during the EO of 30 mg L\({}^{-1}\) of ACT at BDD by applying different \(j\): (**a**) 30, (**b**) 60, (**c**) 90, and (**d**) 120 mA cm\({}^{-2}\). Operating conditions: 0.5 M Na\({}_{2}\)SO\({}_{4}\) and 25 \({}^{\circ}\)C. Black arrows in the UV-vis spectra (a-d) indicate the bands related to ACT (245 nm). conductivity, these values slightly decreased with both EO-based treatments due to the use of the electrolyte, and it was combined in different ways. When the DSA electrode was used, no significant changes were observed; in contrast to the significant decrease achieved at the BDD anode because the sulfate ions were electrochemically converted to persulfate, causing a significant decrease in conductivity and salinity. Turbidity was initially observed due to the preparation of the ACT solution; however, it disappeared after the electrolysis, and the values measured after the treatment are a consequence of the faint color.