Effective adsorption of phosphate using a Mg-Al-La composite from synthetic/real wastewater: adsorptive behaviour, column tests and economic evaluation

The present study utilised an adsorbent that integrates Mg with Al and La (i.e. MAL composite) to remove low-concentration phosphate from wastewater. The adsorption properties of MAL were identified through batch experiments of phosphate removal, in which the impacts of influencing factors such as initial pH and reaction time on the phosphate adsorption by MAL adsorbent were explored. Besides, the thermodynamics and kinetics were also investigated, where the phosphate adsorption follows the pseudo-second-order kinetics, indicating that chemisorption and internal diffusion control dominate the phosphate removal. Dynamic phosphate removal by MAL adsorbent was investigated using a fixed-bed column at different adsorbent particle sizes, flow rates and temperatures, in which the breakthrough curves were simulated. The phosphate removal by MAL adsorbent was examined at practical wastewater treatment, which achieves high efficiency and thus provides a preliminary basis for the commercial use of the adsorbent. Apart from this, the techno-economic analysis of phosphate adsorption was also conducted.