Sustainable Membrane-Based Wastewater Reclamation Employing CO(2) to Impede an Ionic Precipitation and Consequent Scale Progression onto the Membrane Surfaces

CO(2) capture and utilization (CCU) is a promising approach in controlling the global discharge of greenhouse gases (GHG). This study details the experimental investigation of CO(2) utilization in membrane-based water treatment systems for lowering the potential of ionic precipitation on membrane surface and subsequent scale development. The CO(2) utilization in feed water reduces the water pH that enables the dissociation of salts in their respective ions, which leave the system as a concentrate. This study compares the efficiency of CO(2) and other antifouling agents (CA-1, CA-2, and CA-3) for fouling control in four different membrane-based wastewater reclamation operations. These systems include Schemes 1, 2, 3, and 4, which were operated with CA-1, CA-2, CA-3, and CO(2) as antiscalants, respectively. The flux profile and percent salt rejection achieved in Scheme 4 confirmed the higher efficiency of CO(2) utilization compared with other antifouling agents. This proficient role of CO(2) in fouling inhibition is further endorsed by the surface analysis of used membranes. The SEM, EDS, and XRD examination confirmed the higher suitability of CO(2) utilization in controlling scale deposition compared with other antiscalants. The cost estimation also supported the CO(2) utilization for environmental friendly and safe operation.