The large-scale discharge of dye-laden wastewaterWastewater from the textile industry demands efficient and economical treatment solutions. In this work, a novel strategy combining metal ion chelation preciptaition flotation was proposed for the effective removal of Direct Black 38 (DB38), a representative azo dyeAzo dyes. Trivalent metal ions were found to chelate with DB38 molecules, forming hydrophobic flocs that were subsequently removed via flotation. The operational parameters of both chelation and flotation were systematically optimized. Under optimal conditions: Al(II) concentration of 40 mg/L, pH 7–8, chelation time of 25 min, SDS dosage of 40 mg/L, air flow rate of 70 mL/min, and flotation duration of 35 min, the removal efficiency of DB38 exceeded 95%, with the treated effluent achieving a turbidity below 0.1 NTU, meeting discharge standards. This work provides a green and practical approach for the purification and potential resource recoveryRecovery of dye industrial wastewaterWastewater.