Plasma-Based Technology Enables Efficient Produced-Water Treatment, Recycling, and Reuse

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 226921, “A Novel Plasma-Based Technology for Efficient Produced-Water Treatment, Recycle, and Reuse,” by Anton Manakhov, Subhash Ayirala, SPE, and Dongkyu Cha, SPE, Saudi Aramco. The paper has not been peer reviewed. _ Advanced oxidative processes (AOPs) increasingly are recognized for their efficacy in degrading persistent organic pollutants, pathogens, and other contaminants in water treatment. Among AOP techniques, plasma chemistry stands out because of its synergistic integration of physical and chemical effects, enabling efficient degradation of complex pollutants. This study focuses on applying plasma-based AOPs for the treatment of produced water (PW), which contains contaminants including hydrocarbons, heavy metals, and dissolved solids that challenge conventional methods. Introduction This study explores the application of low-temperature plasma for the treatment of mixed-dye effluents, examining the interplay between different dye classes and the role of reactive species in simultaneous degradation. By evaluating key parameters such as discharge type, solution composition, and reaction kinetics, this work aims to enhance the scalability and efficiency of plasma-based AOPs for industrial wastewater treatment. Plasma-solution systems have emerged as a promising approach for the synthesis of nanostructures, offering advantages such as reductant-free processing, simple experimental design, and continuous synthesis under plasma exposure. These systems enable the direct generation of reducing agents during nanoparticle formation, distinguishing them from conventional liquid-phase methods. In this work, the plasma treatment of the synthetic wastewater created can effectively break down organic pollutants and remove petroleum contaminants. The developed upscaled plasma reactor is a modular, flow-type system with a length adjustable to varying solution volumes. The reactor enables simultaneous underwater plasma discharges through as many as eight electrodes powered by a high-voltage circuit. Testing revealed its effectiveness in altering interfacial tension (IFT) between oil and displacing fluid, with notable reductions under optimized conditions. Equipment and Processes The testing of the modeled PW treatment was performed using an in-house-made flow-type prototype that consists of three parts: a reservoir with the initial high-salinity water, a plasma reactor, and a reservoir with treated water (Fig. 1). The total volume of the solution being processed was 7.5 L, with a total capacity of 10 L. Voltage was supplied to the electrodes from a high-voltage transformer through an autotransformer. The design of the prototype installation has two current inputs, making it possible to ignite a discharge using two diaphragms. A plasmachemical cell is a structure of two glass containers in the form of cylinders, one inserted into the other, providing for the circulation of the solution using a peristaltic pump. Solutions of two compositions were prepared for the testing. A solution with a specified salinity was subjected to an underwater diaphragm discharge from an alternating-current source operating at 50 Hz. The duration of the therapy was 60 minutes. The discharge’s electrical properties were documented using an oscilloscope and an analog-to-digital converter. A comprehensive calculating approach for discharge parameters, including efficiency, is described in the complete paper.