Optimization of Removal of Phosphate from Water by Adsorption Using Biopolymer Chitosan Beads

The need for clean water is the most basic human right. Water scarcity will be one important environmental problem of all countries in the future. Phosphate is a harmful matter for public health and the environment. In this study, the removal of phosphate from water by chitosan, which is an environmentally friendly material, was investigated. Chitosan adsorbent spheres were prepared for phosphate separation from water by adsorption, which is a feasible method. The effects of phosphate concentration, adsorbent dosage, and operation time on the removal were investigated. The removal increased with acid concentration and adsorbent amount. The maximum adsorption capacity of chitosan beads is 87.26 mg/g. Adsorption behavior of the chitosan beads were examined by Langmuir and Freundlich isotherms and pseudo-first and second-order kinetic models. The adsorption process was optimized by the response surface method (RSM). Trial version of Design Expert® 12.0 was used in the study. It has been understood as a result of the RSM statistical analysis that higher phosphate removal values would be obtained by increasing the amount of adsorbent. ANOVA analysis showed that adsorbent dosage had the biggest effect on removal of phosphate using chitosan beads prepared for adsorption.