Reuse of phosphogypsum and phosphorus ore flotation tailings as adsorbent: The adsorption performance and mechanism of phosphate

Phosphogypsum (PG) and phosphorus ore flotation tailings (POFT) are generated in the phosphorus chemical industry, where stockpiling PG and POFT causes serious pollution to the environment. In this study, a novel adsorbent material (i.e., PGTA) was prepared in proportion to PG, POFT and starch to remove phosphate from the aqueous solution. Batch experiments were conducted to investigate the adsorption performance of PGTA for phosphate. The effects of various factors such as initial pH and coexisting anions on the phosphate adsorption were investigated as well as the properties of the PGTA adsorbent. The results showed that the optimum initial pH for phosphate adsorption was 5.15 and amount of PGTA was 1.5 g/L. The pseudo-second-order kinetic model fitted well with the adsorption process of the phosphate while the maximum adsorption capacity of phosphate was 31.28 mg/g as stimulated in the Langmuir model. In conclusion, the PGTA adsorbent could be used for effective phosphate elimination, which positively contributes to the sustainable disposal of PG and POFT.