Study On The Phosphorous Removal From Wastewater By La-Fe Oxides Adsorben And Its Vacuum Regeneration

At present, the eutrophication has become one of most serious problems in water environment. Phosphorus is the main factor of the eutophication, so it is great meaningful for removing phosphorous from wastewater. Based on the current low regeneration efficiency of water removal agent problem, this paper proposed a new preparing method of phosphorus agent under the precondition of large research achievements and crystal defect theory. We hope could prepare a kind of phosphorus agent both has good adsorption and regeneration functions, also providing a new technology for phosphorus removing from water.This research used coprecipitation method for preparing lanthanum oxidizing material containing iron impurity as sewage phosphorus agent, known as La-Fe oxides adsorben, for sewage phosphorus experiments and vacuum regeneration experiments.In order to investigate whether the introduction of iron impurities in lanthanum phosphate could improve the pyrolysis process, the experiments of lanthanum phosphate thermal decomposition were carried out firstly. The results showed that the efficiency of thermal decomposition of the lanthanum phosphate containing iron was higher than that of the pure lanthanum phosphate which was in accordance with the subject topics of crystal defects theories and verify the feasibility of the paper topics.The selective conditions for preparing the best La—Fe oxides adsorben were as fallows:the impurity content was MFe/MLa=0.08, the reaction temperature was 60℃, the reaction time was 120 min, the electric stirring rate was 1500 r/min, the drying temperature was 120℃, the drying time was 8h.The adsorption kinetics of La—Fe oxides adsorben was in accordance with second order reaction rate equation, the adsorption isotherm was in accordance with Langmuir model, and the optimal adsorption in terms of pH was at the range of 3-6. The adsorben was suit to treat the wastewater of high phosphorus concentration and weak acid.The regeneration experiments showed that, La—Fe oxides adsorben has the most intense reaction when the calcination temperature is in 1000-1200℃. However, due to the limit of the laboratory conditions, the regeneration hasn't been studied when the calcination temperature is above 1500℃. In the reaction conditions of the experimental control, the maximum regeneration rate of La—Fe oxides adsorben is 62.67%,26.77 percentage higher than previous which was 35.9%.