Manganese　pollution　particularly　in　the　form　of　dissolved　Mn2+　is　an　important　problem　in　groundwater　treatment.　The　main　approaches　for　Mn2+　removal　from　groundwater　are　chemical　catalytic　oxidation　and　biological　oxidation.　Their　relative　attribution　to　Mn2+　removal　and　relationship　has　not　been　clarified　at　the　matured　stage.　An　influent　of　water　containing　2.0　and　4.0　mg/L　Mn2+　was　filtered　through　columns　filled　with　manganese　sand　that　had　either　been　inoculated　with　a　manganese-adapted　microbial　community　or　had　been　pre-oxidized　with　potassium　permanganate.　Either　treatment　resulted　in　good　manganese　removal　capacities　that　maintained　a　final　concentration　in　the　effluent　below　0.05　mg　Mn2+/L　at　two　concentrations　for　a　period　of　130　d.　Among　the　matured　period,　the　direct　contribution　rate　of　biological　manganese　removal　was　less　than　20%.　During　operation,　biological　induction　and　chemical　induction　were　both　responsible　for　the　formation　of　hexagonal　Birnessite-type　manganese　oxide,　whose　physical　characteristics　were　characterized　and　determined.　Biological　oxidation　and　chemical　catalytic　oxidation　in　the　maturation　of　filter　media　were　interlinked　through　the　formation　of　Birnessite-type　manganese　oxide.　Manganese　removal　during　maturation　was　mainly　attributed　to　cyclic　autocatalysis　rather　than　biological　factors.