Study on Phosphorus(P) Fixation in the Sediment of Lake Using the Clays Modified by LaCl3
氯化镧改性黏土固化湖泊底泥中磷的研究

14 kinds of clay modified by LaCl3 were prepared and their phosphorus (P) fixation was studied. The effect of pH on adsorption rate of P using kaolin modified by LaCl3 and dissolved concentration of La3+ from them were also discussed. The results showed that the fixation rates of P using clay modified by LaCl3 were improved to 52%~95% from 3%~14% using unmodified clay. The maximum adsorption rate of P using kaolin modified by LaCl3 was 94.85% on the pH value of 5. Under the condition of pH range from 4 to 8, the P adsorption rate was higher than 80%. When the pH value was higher than 6.5, the dissolved concentration of La3+ from the modified clay was lower than 0.0178mg/L. This research provided an important way to solve internal phosphorus pollution in sediments of lakes.