Phosphate ions are responsible for the algal bloom in receiving water bodies and aesthetic problems in drinking water. From the environmental and economic points of view, management of such a contaminant and valuable resource is very important. The present paper deals with the removal of inorganic phosphate ions from aqueous solutions using synthetic HSZ 330 HUD Zeolite (Si/Al ratio:  2.75−3.25) and its Al3+-activated form (Al-HUD) as adsorbents. Equilibrium and kinetic experiments were performed to study the effects of operating conditions such as adsorbent mass, solution pH, coexisting ions, and initial concentration on either the capacity or the rate of phosphate uptake by the zeolites. As a result, it was found that the efficiency of phosphate removal by the zeolites increased with an increase in adsorbent mass and a decrease in solution pH. Outer-sphere complex-forming ions such as nitrate, sulfate, and chloride improved slightly the phosphate removal efficiency while fluoride ions, which form inner-sphere complexes with binding sites, reduced the phosphate uptake capacity of the sorption sites. Equilibrium data were well-fitted with Langmuir, Freundlich, and Dubbinin−Radushkevitch isotherms. In the kinetic study, mass-transfer processes in the external and internal matrix of the sorbent were considered. The overall adsorption process was assumed to be controlled by intraparticle diffusion.

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The paper focuses on development of new adsorbent material of aluminophosphate (FAM-Z05) which could be subsequently used in utilization of waste heat below 373 K. To evaluate this new material, water vapor adsorption isotherms of FAM-Z05 were measured at several temperatures. Furthermore, an attempt was made to improve the heat exchanger by coating FAM materials onto fin tube type heat exchanger. Then, the dehumidification performance of direct cooling and heating desiccant system was evaluated.It was found that the water vapor adsorption isotherms of FAM-Z05 were characterized by S-shape and the adsorption character of FAM-Z05 was dependent on temperature. Further, the new adsorbent of FAM-Z05 was able to adsorb water vapor in lower regeneration temperature than FAMZ02 and FAM-Z01, which was attributed to FAM-Z05 ability to adsorb water vapor in high humidity range. However, when FAM-Z05 is used in low humidity range, the dehumidification performance of FAM-Z05 might be lower than those of FAM-Z01 and FAM-Z02.

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