The contamination of water by metallic, anionic, organic, and pharmaceutical pollutants represents a major environmental challenge due to their toxicity, persistence, and low biodegradability. In this context, this work proposes the valorization of polyacrylonitrile (PAN) waste as an innovative and sustainable adsorbent material for the simultaneous removal of anions, metal cations, synthetic dyes, and persistent pharmaceutical substances. Two functionalization processes were implemented to endow the material with a dual retention capacity: the use of hydroxylamine enabled the conversion of nitrile groups into amidoximes, conferring a strong affinity for anions such as NO₃⁻ and PO₄³⁻, while the functionalization with monochloroacetic acid led to the formation of iminodiacetic acid groups, ensuring excellent complexation of metal cations such as Cu²⁺, Cd²⁺, Pb²⁺, and Cr(VI). This dual functionalization positions the modified PAN as a versatile adsorbent material, capable of effectively treating a wide range of pollutants in aqueous solution, while recycling an abundant polymeric waste.

Physicochemical characterization (FTIR, BET, PZC, SEM/EDS) confirmed the surface modification and the significant increase in active site density. The adsorbent was also evaluated for the removal of representative dyes—crystal violet, methyl orange, direct, reactive, and dispersed dyes, malachite green—as well as chloroquinoline as a model pharmaceutical molecule. The results showed...