This　study　presents　a　comparative　evaluation　of　two　sequencing　batch　reactors　(SBRs)　with　distinct　height-to-width　(H/W)　ratios　treating　high-ammonia　anaerobically　digested　sludge　supernatant　via　the　nitritation-denitritation　process.　The　reactors　were　designed　with　constant　volumes　but　differing　H/W　ratios,　4.8　for　R1　and　2.8　for　R2,　while　maintaining　identical　superficial　gas　velocity　(SGV),　to　isolate　the　effects　of　reactor　configuration.　Both　systems　consistently　achieved　∼99　%　ammonium　nitrogen　(NH4+-N)　removal　throughout　operation,　with　total　inorganic　nitrogen　removal　efficiencies　of　95　%　in　R1　and　97　%　in　R2.　Kinetic　analysis　revealed　that　R2　achieved　higher　microbial　activity,　with　maximum　AOB　and　denitritation　activities　of　0.57　and　6.32　g　N/g　VSS/d,　respectively,　compared　to　0.49　and　5.12　g　N/g　VSS/d　in　R1.　Conversely,　R1　demonstrated　better　sludge　settleability,　with　final　SVI30　values　of　90　mL/g　compared　to　120　mL/g　in　R2.　Microbial　community　profiling　revealed　comparable　population　structures　in　both　reactors,　with　both　systems　dominated　by　the　same　key　functional　microorganisms:　Nitrosomonas　as　the　predominant　ammonia-oxidizing　bacteria　(AOB)　and　Thauera　as　the　primary　denitrifying　bacteria.　These　findings　indicate　that　while　a　lower　H/W　ratio　enhances　microbial　activity　and　nitrogen　removal,　a　higher　H/W　ratio　improves　sludge　compaction　and　settling.　©　2025　The　Authors