Fixed-bed Column Dynamics of Ultrasound and Na-functionalized Diatomite to Remove Phosphate from Water

Abstract

A continuous fixed-bed column study has been used to evaluate phosphate adsorption performance of U-D-Na which was functionalized by the cheap NaCl reagent after simple ultrasonic purification of diatomite. Experimentally, various effect factors, the flow rate, the initial phosphate concentration, and the bed height on breakthrough time of fixed column were studied. Experimental results showed that the breakthrough time declined with the increase of inlet phosphorous concentration and feed rate, whereas the increase of bed height turned out to significantly prolong the breakthrough time. The dynamic adsorption data could better be fitted by the Thomas model, with the correlation coefficients obtained, R2 > 0.9000 at the majority of operating conditions (5/7). At least thrice loop of adsorption and desorption was achieved with 0.1 M hydrochloric acid eluent and deionized water. The results proved that U-D-Na could be used as a better alternative phosphate adsorbent from wastewater in a continuous column process.