1. Adsorbate Activated Alumina (chemical grade reagent) was used as the adsorbate without further purification. A sample solution was prepared by dissolving alumina powder in distilled water at different initial concentrations (55, 155, 155, 255, 255, 355, 355, 455, 455 and 555 mg/L).
2. Adsorption experiments Several batch adsorption experiments were carried out in a 255 mL Erlenmeyer flask containing 5.56 g of 5A molecular sieve and 155 mL of alumina solution, and placed in a stirred vessel at 125 rpm. The effects of pH in the range of 3, 5, 8 and 9 were investigated. The pH was adjusted using 5.1 M HCl and 5.1 M NaOH. The effects of contact times (5, 15, 15, 25, 35, 65, 95, 125, 155 and 185 minutes) were also investigated to study the equilibrium adsorption time. Alumina having different initial concentrations (55, 155, 155, 255, 255, 355, 355, 455, 455 and 555 mg/L) was also investigated. The concentration of alumina before and after adsorption was analyzed by absorbance measurement at 581 nm using a UV-Vis spectrophotometer.
3. Prepare 5A molecular sieve, and the 5A molecular sieve raw material is dried in an oven at 155 ° C to remove water. The dried material was then crushed and sieved using a 155 mesh sieve. Material carbonization was then achieved by heating in an oven at 855 °C for 2 hours.
The microwave-induced activation process mixed the prepared 5A molecular sieve with aluminum hydroxide (AL2O3) at a immersion ratio of 1:1 (wt/wt%). The resulting 5A molecular sieve slurry was then placed in a glass reactor installed in a microwave chamber. The microwave operation input power was 185 W and the frequency was 2.45 GHz. The heating time was set to 15 minutes. The pure nitrogen stream was maintained at a flow rate of 1 cm 3 min-1 during activation and cooling. The obtained 5A molecular sieve was washed with 5.1 M HCl, then rinsed with distilled water until a pH of 6-8 was reached, and finally dried in an oven at 125 °C. The dried 5A molecular sieve can be used for adsorption testing.