| Abstrakt: |
Large quantities of orange peel wastes are generated and require adequate management and disposal into the environment. Agricultural waste valorization is a strong research topic, due to the increasing need for achieving a sustainable environment. Especially, the development of adsorbent materials applied to wastewater treatment for efficient phosphorus recovery and reuse systems is a challenge of current interest in research. In this work, a novel low-cost biocomposite was obtained by calcination of orange peel (OP) and eggshell (ES), which is highly effective for P recovery from synthetic aqueous solutions and domestic wastewater. After calcination at 700 °C, the material with a ratio by weight of OP/ES = 1 showed a high adsorption capacity (Qmax = 315.25 mg P/g) compared to other materials previously reported. The XRD and FTIR characterization results of the materials after the P removal showed that brushite (Ca(HPO4)•2H2O) is the main calcium phase obtained at pH 6, while apatite (Ca5(PO4)3OH) is favored at a pH higher than 8. Moreover, the ESOP adsorbents showed a high P adsorption from wastewater, with 98.6% of P recovery as apatite. Additionally, Ca5(PO4)3OH and Ca(HPO4)•2H2O phases exhibited a high solubility of P in 2% formic acid releasing up to 97.50 and 194.22 mg P/g. The results of this work indicate that calcined ESOP is a promising material for P recovery from aqueous solution, forming calcium phosphates with great potential to be used as alternative phosphate fertilizer, contributing to implementing the 3R slogan "Reduce, Reuse, Recycle" based on a circular economy. [ABSTRACT FROM AUTHOR] |
Full text from SpringerLink