Sustainable Development in Dye Waste Managemen : A Comparative Study on the Effectiveness of Adsorption and γ-Radiolysis

Abstract

Pyrromethene 567 (PM567), a BODIPY class of dye; is widely used in medicine, chemistry, material science, and high-power dye lasers. During its use, PM567 dye waste is generated in ethanol solvent which needs to be treated before its disposal. In our study, we -radiolysis, an advanced oxidation process (AOP), and adsorption, a simple and easy option. Interestingly, -radiolysis were not efficient for dye effluent treatment in organic solvents. This inefficiency was attributed to competing reactions leading to the scavenging of dye-degrading radicals. -dose rate (3.5 kGy) feasible in the system; 62% is the maximum removal efficiency achieved by this method. For a comparison, we also investigated the adsorption efficiency of PM567 dye from ethanol solvent using commercially available adsorbents. Among these, powdered activated carbon (PAC) demonstrated the highest removal efficiency, reaching 95%, much higher than that of -radiolysis method. In line with the pursuit of sustainable development, we synthesized granular activated carbons (AC1, AC2, AC3) from coconut shells, a lignocellulosic biowaste. The characterization of these carbons revealed that AC3, with a higher iodine value and CCl4 activity, possessed a systematic pore structure (SEM analysis), a larger specific surface area (1708 m2 .g-1), and a higher micro-pore volume (0.61 cc.g-1). AC3 hence, emerged as the most effective adsorbent, achieving 95% efficiency comparable to PAC.