Cavitation-Assisted Intensified Oxidation Solutions to Real Industrial Wastewater Streams in KSA

Human life relies on energy and water resources for bodily functions, food cultivation, and daily materials. Agricultural and industrial processes introduce toxic chemicals into wastewater, with industrial wastewater accounting for 15% of global water use. These wastewaters contain engineered substances that cannot be discharged into natural habitats due to high organic and solid content. When introduced to freshwater, they cause chronic issues for humans and aquatic life1, 2. The secondary stage of wastewater treatment deals with broad oxidation processes. Conventional methods, like activated sludge and trickling filters, have drawbacks such as long treatment times and large land requirements, highlighting the need for more efficient methods3, 4. Advanced oxidation processes (AOPs) are those which can generate reactive radicals which help break down chemical moieties in water, otherwise found challenging for conventional oxidation processes. AOPs can be classified into those which can be initiated by adding chemicals such as hydrogen peroxide, ozone or chlorine containing chemicals, electrochemical based ones and those which are based on catalyst's (such as Fenton's oxidation and photocatalysis5). Fenton's treatment is an aggressive chemical treatment, which is highly capable of oxidizing large pollutant concentrations6. Fenton's chemistry has been used as a reliable treatment technique for different effluents and is industrially implemented. The rapid oxidation of iron (II) to iron (III), and its regeneration, to produce a high and steady quantity is preferred for extremely high organic content waters. However, the sludge formed and the rapid increase in temperatures are disadvantages of this technique when applied to real industrial environments. The reactions of this chemistry are listed in reactions (R1 to R4) below.