Abstract <p>Petroleum operations generate complex wastewater containing a diverse mixture of organic and inorganic pollutants that pose serious threats to both environmental and public health. While conventional treatments – such as gravity separation, dissolved air flotation, and biological processes – have been utilized for decades, they are often unable to meet increasingly stringent discharge regulations or water reuse standards. This shortfall is primarily due to the persistence of recalcitrant organics and emerging contaminants. The purpose of this systematic review was to evaluate three new treatment processes – electrocoagulation (EC), electro-oxidation (EO), and ozone treatment (ozonation) — relative to their ability to effectively treat petroleum wastewater by examining all relevant studies published between 2021 and 2025. The review uses a clear, explicit method for literature search and well-defined inclusion/exclusion criteria to provide a systematic comparison of alternative water treatment technologies with the baseline conventional technology. Key Findings include: (1) Electrocoagulation demonstrated turbidity removal of 44–99% and Oil/Grease removal of 99.6%. However, major issues are present with electrode passivation, metallic sludge formation, and energy consumption ranging from (0.5 to 5.0) kWh/m³. (2) Electrooxidation has shown greater ability to mineralize recalcitrant organic material than other oxidation processes (greater than 85% COD reduction). However, it is very expensive in terms of capital cost ($1.00-$10.00/m³), has very high energy requirements (5.0–50.0 + kWh/m³), and may generate toxic by-products during treatment. (3) Ozonation can degrade complex hydrocarbon molecules; however, it has significant limitations due to the need for managing the transformation products generated as part of its treatment process and also due to high costs associated with generating Ozone and poor mass transfer characteristics. Although these new technologies offer advantages over conventional removal techniques for various types of pollutants, they also pose technical limitations, economic constraints, and environmental trade-offs that need to be evaluated on a case-by-case basis. Technical scale-up of industrial applications is hampered by a lack of implementation standards, adequate pilot-scale testing, and economic viability studies. A significant potential area of future study could be the use of advanced oxidation technologies within hybrid system configurations (e.g., electro-peroxone or catalytic ozonation), but would require full life-cycle assessments and the development of standard operating procedures for both individual and hybrid systems.</p> Graphical abstract <p></p>