Chemical　conditioning　emerges　as　a　pivotal　determinant　in　augmenting　sludge　dewatering　performance.　In　the　realm　of　frequently　employed　aluminum　chloride　polymer　conditioners,　the　impact　of　hydroxyaluminum　is　noteworthy.　Beyond　influencing　dewatering　efficacy,　it　introduces　chloride　ions,　precipitating　a　cascade　of　subsequent　treatment　challenges.　In　this　study,　we　investigated　the　dewatering　efficiency　of　coagulants　with　varying　aluminum　speciation　contents.　Notably,　the　coagulant　predominantly　composed　of　medium　polymeric　aluminum　(Alb)　demonstrated　superiority　at　a　dosage　of　0.08　g　Al/g　TSS,　exhibiting　favorable　outcomes　in　terms　of　capillary　suction　time　and　specific　resistance　to　filtration,　measured　at　22.3　s　and　4.02　x　1012　m　　1/kg　　1,　respectively.　These　values　were　notably　lower　compared　to　those　obtained　with　low-polymerization　state　aluminum　(Ala)　at　25.2　s　and　6.04　x　1012　m　　1/kg　　1,　as　well　as　high　polymorphic　aluminum　(Alc)　at　25.8　s　and　4.69　x　1012　m　　1/kg　　1.　It　was　attributed　to　multifactor　(high　charge　density,　high　protein　conversion　efficiency,　distinct　pore　drainage　structures　of　microchannels,　etc.).　The　investigation　underscored　that　the　predominant　elevation　in　chloride　ion　content　within　the　sludge　system　was　primarily　attributed　to　the　dosing　of　poly　aluminum　chloride.　Furthermore,　the　subsequent　application　of　coagulant　aids,　such　as　cationic　polyacrylamides　and　CaO,　significantly　influenced　the　chloride　ion　content　within　the　sludge　cake,　thereby　modulating　dewatering　efficiency　and　the　subsequent　disposal　of　sludge.　Therefore,　strategically　managing　aluminum　forms　and　coagulant　aids　can　optimize　sludge　dewatering　efficiency　and　subsequent　disposal　processes.