The　aim　of　the　present　work　was　to　evaluate　the　anaerobic　ammonium　oxidation　(anammox)　activity　of　simultaneous　partial　nitrification,　anammox　and　denitrification　(SNAD)　biofilm　with　different　substrate　concentrations　and　pH　values.　Kaldnes　rings　taken　from　the　SNAD　biofilm　reactor　were　incubated　in　batch　tests　to　determine　the　anammox　activity.　Haldane　model　was　applied　to　investigate　the　ammonium　inhibition　on　anammox　process.　As　for　nitrite　inhibition,　the　NH4+-N　removal　rate　of　anammox　process　remained　87.4%　of　the　maximum　rate　with　the　NO2--N　concentration　of　100　mg/L.　Based　on　the　results　of　Haldane　model,　no　obvious　difference　in　kinetic　coefficients　was　observed　under　high　or　low　free　ammonia　(FA)　conditions,　indicating　that　ammonium　rather　than　FA　was　the　true　inhibitor　for　anammox　process　of　SNAD　biofilm.　With　the　pH　value　of　7.0,　the　r(max),　Ks　and　K-I　of　ammonium　were　0.209　kg　NO2--N/kg　VSS/day,　9.5　mg/L　and　422　mg/L,　respectively.　The　suitable　pH　ranges　for　anammox　process　were　5.0　to　9.0.　These　results　indicate　that　the　SNAD　biofilm　performs　excellent　tolerance　to　adverse　conditions.　(C)　2016　The　Research　Center　for　Eco-Environmental　Sciences,　Chinese　Academy　of　Sciences.　Published　by　Elsevier　B.V.