The effectiveness of water treatment waste alum sludge in eliminating fluoride from water was experimented. Alum sludge dose (1–10 g/L), pH (3–8), initial fluoride concentration (5–25 mg/L), and influence of various anions (nitrate, sulphate, phosphate, and silicate) were all examined across the experiments that were executed in order to eliminate fluoride from water. The results show that the fluoride concentration of 1.26 mg/L was achieved which is well within the desired range with TASP adsorbent dose of 5 g/L at pH 6 and at contact time of 3 h. At initial fluoride concentration of 10 mg/L, the desired range of fluoride was achieved with removal of 87%. The effect of presence of anions showed that nitrate ion showed least interference in fluoride removal (65.66%), followed by sulphate (37.94%), phosphate (10.93%), and silicate ions (6.49%). First-order kinetics were monitored through the Lagergren equation and were found well fitting (R2 0.9227). This current approach followed Langmuir’s adsorption isotherm model (R2 0.9659). An economical and environmentally friendly adsorbent for removing fluoride from water is alum sludge.