有机酸对五种人工合成磷酸盐活化作用及活化途径的研究

摘要

采用实验室合成和化学浸提方法,研究了高分子量腐殖酸和低分子量柠檬酸在不同浓度条件下对五种人工合成磷酸盐的释磷效应及活化途径。结果表明,两种有机酸均能促进五种人工合成磷酸盐中磷素的释放,且释磷量随有机酸浓度的增加而增大;其中柠檬酸的活化能力明显强于腐殖酸;腐殖酸对三种钙磷的活化效果较好,而Fe-P和Al-P基本不受其影响或影响很小。柠檬酸通过质子和有机阴离子的共同作用来活化人工合成Ca2-P、Ca8-P和Al-P中的磷,Ca10-P中磷的活化几乎完全依靠质子作用,而低浓度有机酸作用下Fe-P的活化则来源于有机阴离子的作用。%Effects of high-molecular-weight,humic acid and low-molecular-weight organic acid,citric acid,with different concentrations on phosphorus release from synthesized phosphates and its activation pathway was studied using lab-synthesis method and chemical extraction.The results show that both organic acids,humic acid and citric acid,improved phosphorus release from different synthesized phosphate compounds,and the activation intensified with the increasing of organic acid concentration.The ability of citric acid in mobilizing phosphorus from synthetic phosphate is stronger than that of humic acid.Humic acid could activate all three Ca phosphates,but had slight effect on Fe-P and Al-P.Citric acid increased the phosphorus releasing of Ca2-P,Ca8-P and Al-P through the combined action of proton and citric anion.Almost all the phosphorus mobilized from Ca10-P by citric acid was attributed to the proton effect,while under the low organic acid concentration,the phosphorus mobilized from Fe-P was caused by citric anion effect.