Mesoporous　magnetic　NiFe2O4/ZnCuCr-LDH　composite　is　synthesized　by　an　environmental-friendly　hydrothermal　process　from　saccharin　wastewater　to　achieve　the　goal　of　＂treating　the　wastes　with　wastes＂.　During　this　process,　all　waste　iron-catalyst　and　82%　of　chemical　oxygen　demand　(CODcr)　are　removed　from　the　wastewater.　The　composite　is　characterized　by　FT-IR,　XRD,　SEM,　EDS,　TEM,　XPS,　BET,　and　VSM　analyses　and　its　potential　for　wastewater　treatment　is　evaluated　by　Congo　Red　(CR)　adsorption.　An　over　97%　removal　efficiency　is　achieved　with　an　initial　CR　concentration　ranging　from　100-450　mg/L.　The　adsorption　kinetic　is　investigated　and　it　is　found　that　the　experimental　data　agrees　well　with　the　pseudo-second-order　kinetic　model,　intra-particle　diffusion　and　Langmuir　adsorption　isotherm　model.　Adsorption　isotherm　indicates　a　spontaneous　and　endothermic　adsorption　type.　The　adsorption　mechanism　is　also　explored　and　the　important　roles　of　electrostatic　attraction　and　anion　exchange　are　demonstrated.　(C)　2019　Elsevier　B.V.　All　rights　reserved.