Adsorption using activated carbon is an effective and inexpensive widely method to mitigate the exceed of tripolyphosphate ion. Activated carbon in this research was synthesized from black liquor sludge by coagulation process using polyaluminum chloride (PAC) and treated by steam activation at 725 °C. The characterization using FTIR shows that this activated carbon has some functional groups that are similar to commercial-AC. Based on the result of SEM-EDX measurement, it contained 42.52 % carbon and 21.17 % oxygen. The BET analysis showed that the specific surface areas and pore size of black liquor sludge-AC were 214.9787 m2/g and 3.4377 nm, respectively. A number of parameters, including initial concentrations, adsorbent dosage, and pH solutions were evaluated on a batch system for adsorption performance of black liquor sludge-AC. The results showed that the highest removal percentage of tripolyphosphate ions was 68.45 % with an adsorption capacity of 1.1251 mg/g at tripolyphosphate concentration of 3 mg/L, pH of 3 and 0.1 g of adsorbent dosage. It is concluded that the activated carbon from black liquor sludge initiated to have a desirable capability is promising to potentially remove the tripolyphosphate ion in wastewater.