[Removal of phosphorus from aqueous solution by lanthanum hydrate]

Aiming at the development of novel efficient absorbents for phosphorus removal from wastewater, metal hydrates (MeH) were selected as adsorbent material. Several kinds of MeH were tested for phosphorus adsorption, and lanthanum hydrate (LaH) was found to possess a high adsorption capacity. Corresponding to solution pH change, LaH' s adsorption capacity changed largely, and at about pH = 3 reached the peak. Its adsorption isotherm accorded prefer Langmuir's to Fruendrich's equations. Influences of different anions on its adsorption capacity were tested. This adsorbent was effective to adsorb orthophosphate but limited to remove polyphosphoric anion. The experimental results demonstrated that the LaH adsorbent was superior to traditional activated alumina adsorbent in adsorption performance.