The　recycling　and　conversion　of　discarded　pericarp　into　useful　materials　are　tally　with　the　sustainable　development　concept.　In　this　work,　raw　orange　peel　(OP)　was　pretreated　by　alkaline　hydrolysis　and　further　decorated　by　mercaptoacetic　acid　(MA)　to　obtain　potential　adsorbents　for　capturing　toxic　Cd(II)　from　aqueous　solutions.　Fourier　transform　infrared　spectroscopy　(FTIR),　X-ray　photoelectron　spectroscopy　(XPS),　zeta　potential,　and　N2-BET　analyses　confirmed　the　successful　preparation　of　modified　OP　materials　with　negatively　charged　surfaces,　decreased　specific　surface　area　(SSA),　and　enlarged　pore　diameter.　The　sorption　kinetics　process　of　Cd(II)　on　the　modified　OP　materials　was　ultrafast　and　a　near　100%　removal　was　achieved　after　10　min.　The　OP-OH　and　MA@OP-OH　composites　exhibited　higher　Cd(II)　sorption　ratios　than　raw　OP　due　to　the　elimination　of　inert　constituents　and　the　introduction　of　active　surface　sites.　In　addition,　the　sorption　of　Cd(II)　was　not　interfered　with　by　most　of　the　common　aqueous　components.　In　desorption　experiments　with　EDTA-2Na　as　the　extractant,　the　lower　Cd(II)　desorption　ratio　from　MA@OP-OH　(72%)　than　those　from　OP-OH　(83%)　and　OP　(87%)　provided　indirect　evidence　for　tight　Cd-sulfhydryl　complexation　on　MA@OP-OH　surfaces.　The　underlying　Cd(II)　removal　mechanism　was　proved　to　be　dominated　by　inner-sphere　complexation.　The　experimental　findings　demonstrated　the　feasibility　of　synthesizing　and　applying　modified　OP　materials　for　the　efficient　purification　of　Cd(II)-bearing　wastewater.　©　2022　Elsevier　B.V.