The　derivation　of　defect-engineered　metal-organic　frameworks　(MOFs)　from　industrial　waste　simultaneously　mitigates　environmental　pollution,　reduces　MOF　synthesis　costs,　and　enhances　adsorption　performance.　Herein,　this　study　demonstrates　a　sustainable　strategy　for　the　resourceful　synthesis　of　an　iron-based　MOF,　s-MIL-100(Fe),　using　galvanizing　pickling　waste　liquor　(80.5　wt%　Fe2+,　18.8　wt%　Zn2+)　as　metal　precursors.　Although　zinc　ions　do　not　incorporate　into　MOF　frameworks,　their　coexistence　induced　the　generation　of　coordinatively　unsaturated　metal　sites　(CUMS),　enabling　s-MIL-100(Fe)　to　achieve　an　ultra-high　adsorption　capacity　of　721　mg　g(-1)　for　doxycycline　(DOX)　at　303.15　K.　In　addition,　Zn-mediated　defect　engineering　increased　the　porosity　of　s-MIL-100(Fe),　yielding　optimized　textural　parameters　(specific　surface　area:　733.4　m(2)　g(-1);　pore　volume:　0.74　cm(3)　g(-1)),　and　outperformed　commercial　c-MIL-100(Fe)　by　48.4　%　in　adsorption　capacity　with　a　shorter　equilibrium　time.　Furthermore,　s-MIL-100(Fe)　exhibited　robustness　across　a　pH　range　of　2-10,　in　multi-ion　matrices　and　under　humic　acid　interference,　while　retaining　90　%　capacity　over　four　regeneration　cycles.　Synergistic　mechanisms　involve　CUMS-driven　coordination,　pi-pi　stacking,　and　pore　confinement,　supplemented　by　hydrogen　bonding　and　electrostatic　interactions.　By　transforming　hazardous　metallurgical　waste　into　high-performance　adsorbents,　this　work　offers　a　sustainable　approach　that　simultaneously　addresses　industrial　waste　management　and　advanced　material　synthesis.　Notably,　s-MIL-100(Fe)　demonstrates　＞97　%　DOX　removal　efficiency　in　real　contaminated　waters,　including　aquaculture　effluents,　municipal　wastewater,　and　river　systems,　validating　its　practical　utility　in　environmental　remediation.　The　Zn-assisted　defect　modulation　strategy　provides　new　insights　into　the　structure-property　optimization　of　waste-derived　MOFs,　highlighting　the　untapped　potential　of　impurity　ions　in　functional　material　synthesis.