Utilization Of Ce/La Hydroxide As Recovery Of Abandoned Rare Earth Polishing Powder For Removal Of Chromium In Water

Based on recycling of solid wastes and treatment of pollutants in waste water, we selected abandoned rare earth polishing powder-solid waste produced by glass manufacturing industry as material, dissolved by addition of proper amount of hydrochloric acid and sulfuric acid, and precipitated by sodium hydroxide solution, then relativerare earth hydroxide was prepared, this product can be used as adsorbing material in chromium ions treatment of waste water. This work opened up new ways for secondary resource reuse and environment protection, and also has important practical significance.Firstly, this paper prepared good adsorption chromium ion adsorption material through hydrochloric acid (or sulfuric acid)Heating-Alkali neutralization precipitation method. Using potassium dichromate as the chromium source, the preparation of the concentrations were standard solution of 2,5,10,20,50 and 100mg/L, under laboratory conditions, the adsorption of Chromium Ions is studied. Ultilizing atomic absorption (AAS) tests concentration of chromium ion, temperature, adsorption time, pH and coexisting ions on the adsorption performance. The results show that the adsorbent has high adsorption performance of chromium ion in the solution.using batch static adsorption experiments on the adsorption performance of materials, which shows that pH value on adsorption performance has the larger impacts, in general, the adsorption under acidic conditions is better than the adsorption under alkaline conditions, and the initial concentration of chromium is lower, the absorbent material has a wider pH range (2-8) adaptability, the affected extent common coexistence inorganic anions on the adsorption of hexavalent chromium is slight. At the beginning, whether different pH value or different initial concentration, adsorptive reactions were quick. With the reaction time extend, reaction slowly and gradually tends to balance. Through Lagergren equation, the results show that the adsorption belonged to divided into two first-order reaction of adsorption stage, Namely, the first stage is diffusion controlling reaction, the second stage is chemical adsorption controlling reaction.Secondly, the reaction mechanism of its adsorption were studied. The results of the study show that adsorptive reactions that has foucus on Langmuir way, and with Freundlich adsorption happened. Basing on Langmuir adsorption isotherm equation, which was deduced for belonging to the entropy drive procedural endothermic reaction,and estimated that the adsorption heat was 39.72 kJ/mol.Finally we investigated the regeneration properties of adsorbent, which could be desorbed by sodium hydroxide solution. Preliminary results showed that optimum desorption condition of the used adsorbing material was sodium hydroxide solution of 100g/mL, which concentration range could be widely, regenerated adsorbing material has the possibility of repeat utilization. The adsorbent showed preferable adsorption effect, when used in chromium ions treatment of real wastewater.