<p>Poly(vinyl alcohol) has been employed as an adsorbent to remove heavy metal (Cu²⁺) and Congo red dye (CRD) pollutants. Metal-coordinated polymer (PVA-Cu), separated from the water–acetone biphasic medium, was utilized for the removal of the dye pollutant. The introduction of Cu²⁺ into the polymer has significantly improved the adsorptive capacity of the polymer towards dye adsorption. The PVA-Cu composite exhibited an optimal CRD removal percentage of 98.77%. However, Cu²⁺ and CRD showed competitive adsorption characteristics when present together in the aqueous medium, and the metal and dye uptake for the polymer reaches 508.22 and 41.66&#xa0;mg/g respectively. The correlation coefficient calculated by fitting with the Langmuir and Freundlich adsorption isotherm models was found to be <i>R</i>² = 0.85 and 0.556 respectively, showing the Langmuir adsorption process taking place preferably with the dye uptake. After three cycles of regeneration, the adsorptive capacity of the PVA-Cu has been found to decrease to 43.2%. The adsorption isotherms and reusability of the PVA-Cu composite for the CRD were also investigated. PVA was found to simultaneously remove Cu²⁺ and CRD, exhibiting preferences towards metal coordination rather than dye adsorption. The prepared PVA-Cu and PVA-Cu-CRD composites were characterized by UV, FTIR, SEM, TGA, BET, XPS, and XRD, and the PVA-Cu composite is considered to be an efficient adsorbent for the dye without the requirement of a crosslinker.</p> Graphical abstract <p></p>