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. 2023 Jan 20;15(3):539.
doi: 10.3390/polym15030539.

Continuous Phosphate Removal and Recovery Using a Calcium Silicate Hydrate Composite Monolithic Cryogel Column

Chanadda Phawachalotorn  1 , Worawit Wongniramaikul  2 , Tarawee Taweekarn  2 , Bussakorn Kleangklao  2 , Wachiraporn Pisitaro  3 , Wadcharawadee Limsakul  2 , Wilasinee Sriprom  2 , Wanchitra Towanlong  2 , Aree Choodum  2
Affiliations

Continuous Phosphate Removal and Recovery Using a Calcium Silicate Hydrate Composite Monolithic Cryogel Column

Chanadda Phawachalotorn et al. Polymers (Basel). .

Abstract

Toward the development of a practical and green approach for removing phosphate from water, a monolithic cryogel based on starch and calcium silicate hydrate (Cry-CSH) was employed as a phosphate adsorbent in a continuous flow system for the first time. The influence of flow rate, initial phosphate concentration, and adsorbent height on the adsorption efficiency was investigated. As the rate of flow and the initial concentration of phosphate increased, the total quantity of adsorbed phosphate dropped; however, the performance of the column was greatly enhanced by an increase in adsorbent height. The experimental data fit the Adams-Bohart model better than the Thomas and Yoon-Nelson models at the beginning of the adsorption process. To evaluate its applicability, the continuous flow system based on the monolithic Cry-CSH column was applied for the removal of phosphate from the discharge effluent of the Patong Municipality Wastewater Treatment Plant (Phuket, Thailand), achieving an excellent total adsorption of 94.61%.

Keywords: calcium silicate hydrate; continuous flow adsorption; phosphate removal; starch cryogel.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Figure 1
Figure 1
Schematic flowchart of an experiment design for column absorption study.
Figure 2
Figure 2
SEM images of Cry–CSH before (a,b) and (c,d) after adsorption of phosphate with magnification of 200 (a,c), and 100,000× (c,d).
Figure 3
Figure 3
XRD patterns of Cry–CSH (a) before and (b) after phosphate adsorption.
Figure 4
Figure 4
FTIR spectra of Cry–CSH (a) before and (b) after phosphate adsorption.
Figure 5
Figure 5
Breakthrough curves for phosphate adsorption onto monolithic Cry–CSH at different flow rates (Ct/C0 is the ratio of effluent phosphate concentration at time t to the influent phosphate concentration).
Figure 6
Figure 6
Breakthrough curves for phosphate adsorption onto Cry–CSH at different phosphate concentrations (Ct/C0 is the ratio of effluent phosphate concentration at time t to the influent phosphate concentration).
Figure 7
Figure 7
Breakthrough curves for phosphate adsorption onto monolithic Cry–CSH at different adsorbent heights (Ct/C0 is the ratio of the effluent phosphate concentration at time t to the influent phosphate concentration).
Figure 8
Figure 8
Breakthrough curve for phosphate adsorption by monolithic Cry–CSH using a real sample.
See this image and copyright information in PMC

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