Performance Evaluation of Calcined Meretrix Lusoria Beads Fixed Bed Column for Instantaneous Removal of Phosphate and Nitrate from Domestic Wastewater

In our previous work, efficient PO₄^3- and NO₃^- adsorption by calcined Meretrix lusoria powder was reported. This study addressed pilot scale application of M. lusoria F800 for PO₄^3- and NO₃^-removal from the real site. The study investigated the performance of multi-component (PO₄^3- and NO₃^-) adsorption from domestic wastewater (DWW) in fixed-bed adsorption column packed with Meretrix lusoria F800 beads. Prior the packing, M. lusoria F800 beads were successfully tested for 20 mg/L PO₄^3- and NO₃^- removal from synthetic wastewater (SWW) and DWW, respectively. In this research study, the effect of the column operational parameter including DWW influent flow rate (Q: 10, 30 and 40 mL/min) and adsorbate concentration (C: ≈ 60mg/L) on breakthrough curves were well-evaluated. Thomas model was used to confirm the correlations of the experimental data with the maximum adsorption capacity of 23.6 mg/g PO₄^3- and 9.31 NO₃^- mg/g, at 10 mL/min flow rates, respectively. Results demonstrated that Thomas model well interpreted the experimental data. Moreover, PO₄^3- and NO₃^- removal capacity by regenerated M. lusoria F800 beads was observed additional adsorption cycle. Furthermore, scale-up column was successfully tested, where experimental values were in parallel with theoretical values. In conclusion, this study indicates that M. lusoria F800 beads can be economically and easily utilized in a fixed-bed adsorption column for the removal of PO₄^3- and NO₃^-from DWW containing excessive PO₄^3- and NO₃^-.

Keywords: Meretrix lusoria. Yoon-Nelson model. Phosphate. Thomas model. Nitrate. Fixed-bed column