Combining　natural　polymer　starch　with　magnetite　nanoparticles　(MNPs)　can　reduce　the　aggregation　of　MNPs　and　enhance　their　adsorption　capacity　and　stability.　Iron　sludge　from　a　de-ironing　water　plant　and　starch　were　employed　as　basic　ingredients　in　this　study.　Bare　magnetite　nanoparticles　(MNPs)　and　starch-coated　magnetite　nanocomposites　(ST2-MNPs)　were　synthesized　by　a　＂green＂　co-precipitation　method　for　the　removal　of　lowconcentration　As(V)　solutions.　TEM,　XPS,　FTIR,　XRD,　VSM,　BET,　and　TGA　techniques　were　used　to　examine　the　physicochemical　properties　of　the　synthesized　ST2-MNPs.　TEM　verified　that　the　magnetite　nanoparticles　in　the　composites　were　evenly　distributed.　The　ST2-MNPs　(5.26　nm)　possessed　a　smaller　average　particle　size　than　MNPs　(6.24　nm).　And　VSM　confirmed　their　remarkable　magnetic　properties.　The　starch-to-iron-sludge　ratio　was　optimized　and　the　influence　of　adsorbent　dosage,　pH,　and　co-existing　anions　on　As(V)　adsorption　were　studied.　The　acquired　arsenate　adsorption　data　were　found　to　be　consistent　with　the　Langmuir　isotherm　model,　with　maximum　adsorption　capacities　of　23.04　mg/g　for　MNPs　and　42.88　mg/g　for　ST2-MNPs.　This　shows　that　the　active　sites　on　MNPs　and　ST2-MNPs　are　energetically　homogenous,　and　that　the　addition　of　starch　coating　significantly　increases　magnetite＇s　adsorption　capacity　for　As(V).　The　adsorption　kinetics　follow　a　Pseudo-secondorder　kinetic　model,　indicating　chemisorption　between　As(V)　and　ST2-MNPs.　In　addition,　the　adsorption　mechanism　of　As(V)　by　ST2-MNPs　including　chemical　adsorption　and　electrostatic　attraction　was　determined　through　in-depth　discussion　of　characterization　methods　and　adsorption　experiments.　This　study　offers　references　for　the　removal　of　As(V)　and　the　resourceful　application　of　backwash　iron　sludge.