Removal of Phosphate from Aqueous Solution by Chitosan-Alginate Beads

Phosphorous is an effective and essential mineral nutrient for the growth of biological creatures and it is very necessary for functioning of ecosystems normally. However, the increase in the usage of phosphorous in lots of parts including industry, agricultural and municipalities causes to pollution of water bodies. Additionally, consumption of water which is rich in content of phosphorous can cause to decrease in the levels of calcium amount of blood and that can result in osteoporosis, hyperphosphatemia and hazard public health. For protection of human health and aquatic ecosystems, the amount of phosphorous should be controlled within the limits (<0.5 mg/L as it has been reported by World health organization). The removal of phosphorous from water bodies relies mostly on the adsorbents usage which are effective. In this study, chitosan-alginate hydrogel beads were prepared by mixing chitosan and sodium alginate solution together and dropping them into calcium chloride solution. Sodium alginate and chitosan mixture causing interpenetrated network improves the resistance of the beads in acidic mediums. For characterization of beads SEM and FTIR analysis were conducted to prove the presence of functional groups and calcium ions which has the main effect in phosphate adsorption. Additionally, UV spectroscopy method was used to study adsorption capacity which illustrated that with increasing adsorbent concentration and time, the amount of adsorbed phosphate increase considerably.