Popis: |
Phosphorus released in lakes due to agricultural runoff causes eutrophication, deteriorating water quality and ecosystem harm. Adsorbing and recovering phosphorus could potentially contribute to a circular economy and reduce eutrophication. A literature review of phosphorus adsorbents was conducted to isolate for ideal adsorbents after defining criteria for surface water adsorption. Two adsorbents were studied for the removal of phosphate from water: plaster of Paris powder and hydrogel beads produced using alginate, carboxymethylcellulose, and aluminum. The reaction kinetics, adsorption capacity, and ability to desorb were compared. In deionised water, hydrogel beads had a maximum sorption capacity of 90.5 milligram phosphate per gram dry bead with an equilibration time of approximately 24 hours. In deionised water, plaster of Paris (POP) powder has a maximum capacity of 1.52 milligram phosphate per gram of powder with an equilibrium time of less than 10 minutes. Sorbents can potentially be reused following phosphate desorption, and desorbed phosphate may be reused as fertilizer. |