氯化镧改性黏土固化湖泊底泥中磷的研究

Study on Phosphorus(P) Fixation in the Sediment of Lake Using the Clays Modified by LaCl_3

用氯化镧对14种黏土进行改性并研究了这些改性黏土固化磷的效果．研究了pH对改性高岭土磷吸附率和镧离子溶出的影响．结果表明，通过氯化镧改性，不同黏土的磷固定率由改性前的3％-14％提高到改性后的52％-95％,氯化镧改性高岭土在pH为5时，达到磷吸附率的最大值94．85％，并在pH值4—8范围内，保持较高的磷吸附率（〉80％）,在pH〉6．5的范围，La^3＋溶出浓度低于0．0178mg/L.

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 La^3＋ from them were also discussed. The results showed that the fixation rates of P using clay modified by LaCl3 were improved to 52% - 95% of P using kaolin modified by LaCl3 was 94.85 % on the pH value of 5 from 3% - 14% using unmodified clay. The maximum adsorption rate 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 La^3＋ from the modified clay was lower than 0.017 8 mg/L.