Adsorption studies of ammonia and phosphate ions onto calcium alginate beads

This study aims to utilize the calcium alginate (Ca-Alg) beads for ammonia and phosphate ions adsorption. The alginate beads were characterized using the scanning electron microscope (SEM) with Energy Dispersive X-Ray (EDX) spectroscopy. The alginate beads showed relatively high removal efficiencies for ammonia ions (94.94%) and phosphate ions (88.31%). For the ammonia ions adsorption, the optimum condition was at the original pH (6.0), alginate beads amount of 5 g/L, ammonia ions concentration of 50 mg/L, and a contact time of 60 min. The optimum conditions for the phosphate adsorption occurred at the original pH, adsorbent amount of 5 g/L, initial concentration of 10 mg/L, and a contact time of 60 min. The adsorptions of ammonia and phosphate ions onto the alginate beads were found to follow Langmuir isotherm and the pseudo-second-order model. The thermodynamic experiments showed that the adsorptions of ammonia and phosphate were feasible and naturally spontaneous. The ammonia and phosphate removal efficiencies from real wastewater reached 40.70% and 10.52%, respectively. The adsorption of ammonia and phosphate ions onto the calcium alginate beads can be used as a fertilizer since the alginate can be biodegraded naturally.

Automated summary

The study demonstrates that calcium alginate beads are effective in adsorbing ammonia and phosphate ions, achieving high removal efficiencies of 94.94% and 88.31% respectively under optimal conditions. The adsorption process follows Langmuir isotherm and pseudo-second-order model, with feasible and naturally spontaneous thermodynamic characteristics. Adsorption onto calcium alginate beads can be utilized as fertilizer due to the natural biodegradability of alginate.