## 2 Advanced Oxidation Processes
### Sono-Based Technologies  
Ultrasound can generate oxidizing radicals from water pyrolysis due to the creation and collapse of microbubbles. This technology can present good advantages but has the  
\begin{table} \begin{tabular}{c c c c c c} \hline \hline
**Pollutant** & **AOP** & **Material** & **Test** & **Results and** & **Reference** \\ \hline MP & Electrolysis Photo-electolysis & BDD anode & \(\bullet\) & BDD used as anode and stainless steel as cathode. & \(\bullet\) & Total MP removal for electrocatalysis and photoelectrocatalysis in 20 min, and about 20\% \\  & & & \(\bullet\) & UVC radiation. & \(\bullet\) \\ MP & Electrolysis Photo-electolysis & & \(\bullet\) & 100 mg/L of MP. 3.7 g/L of NaCl electrolyte solution. & \(\bullet\) & removal in almost 500 min \\ MP & Electrochemical oxidation & BDD anode & \(\bullet\) & 0.05 mol/L of K\({}_{2}\)SO\({}_{4}\) electrolyte solution. & \(\bullet\) & MP removal was 30.12, 34.65, 31.61, 30.07, and 19.85 for 1.35, 2.70, 5.44, 10.8, and 21.6 mA/cm\({}^{2}\) in 120 min. \\ MP & Electrochemical oxidation & BDD anode & \(\bullet\) & 100 mg/L of MP in 1.05 mol/L NaCl solution. & \(\bullet\) & Total removal in 80 and 40 min for 5 and 10 mA/cm\({}^{2}\), respectively. \\ MP & Electrochemical oxidation & & & 100 mg/L of MP in 0.15 mol/L NaCl solution. & \(\bullet\) & Photo electrocatalysis led to 31, 78, and 100\% removal for 1, 2.5, and 5 mA/cm\({}^{2}\), respectively. \\ MP & Electrochemical oxidation & BDD & stainless-steel, and platinum as anode and stainless-steel as cathode. & \(\bullet\) & BuP total removal achieved by BDD in 15 min, while for the stainless-steel and platinum anode, the degradation was 40\% and 18\% respectively. \\ BuP & Electrochemical Oxidation & BDD Stainless-steel Platinum & \(\bullet\) & 0.5 mg/L of BuP in electrolyte solution of 0.1 M of Na\({}_{2}\)SO\({}_{4}\). & \(\bullet\) & DeBut total removal achieved by BDD in 15 min, while for the stainless-steel and platinum anode, the degradation was 40\% and 18\% respectively. \\ \hline \hline \end{tabular} 
\begin{tabular}{c c c c} BuP & Electrochemical Oxidation & Platinum Glassy carbon & \(\bullet\) & Platinum foil or glassy carbon as working electrode, the counter electrode was platinum & \\ MP & Electrochemical Oxidation & Platinum Glassy carbon & \(\bullet\) & Using a real water sample & \\ MP & Electrochemical oxidation & BDD anode & \(\bullet\) & 150 mg/L MP solution & \(\bullet\) & from river, electrolysis led to 95\% BuP removal in 2.5 h. \\ MP & Electrolytic solutions: 0.1 & & & \\ MP & Electro- & & & 10  
disadvantages of high amount of energy needed, low mineralization, and low efficiency, which can make this technology infeasible with difficult implementation at industrial scale. [PERSON] et al. (2018) used photosonochemical degradation for BuP abatement (20 mg/L). The experiments led to a removal of 61.3%, 60.02%, and 87.96% for single UV light, ultrasound, and the combination of both in 120 min. Furthermore, for different experimental conditions (BuP concentration = 10 mg/L, US/UV experiment, 40 W, pH = 7) a removal of 99.2% removal was achieved. [PERSON] et al. (2018) removed about 92% of MP using the best operational parameters of T = 20 \({}^{\circ}\)C, pH = 6, power density of 60 W/L and the presence of biochar. This result was similar to the conclusions obtained by [PERSON] et al. (2018), which showed 99% MP removal using an ultrasound frequency of 350 and 620 kHz, or a power density of 40.25 and 22.75 W/mL. Ultrasound was also tested in the presence of a catalyst. [PERSON] et al. (2019) studied sonocatalysis for MP removal using bimetallic Co-Fe carbon xerogel as a catalyst. Adsorption into catalyst was 29.2% of MP in 60 min, and sonocatalysis led to 54.6% removal in 60 min for a power density of 25 W/L, but almost full removal was obtained in 45-60 min, when the power density was increased to 52 W/L. In general, the removal of parabens was achieved, and high parabens degradation was reported.