低分子量有机酸对不同合成磷源的释磷效应

采用化学浸提方法,研究了5种低分子量有机酸(草酸、柠檬酸、酒石酸、苹果酸、乙酸)对不同合成磷源的释磷效应。结果表明:供试有机酸(低浓度乙酸除外)均能促进不同合成磷源(DCP、OCP、FA、Fe-P、A l-P)中磷素的释放;其释磷效果与有机酸的种类和浓度有关,强弱顺序依次为柠檬酸、草酸、酒石酸、苹果酸、乙酸,有机酸浓度越高其释磷效果越好;有机酸与氟磷灰石(FA)反应后,溶液pH值升高。低浓度条件下pH值变化较大,而高浓度条件下pH值变化较小。

Effect of Low-molecular-weight Organic Acids on the Release of P from Synthetic Phosphate Compounds

Effect of low-molecular-weight organic acids(oxalic acid,citric acid,malic acid,tartaric acid and acetic acid) on the release of phosphorus from synthetic phosphate compounds was studied with chemical extraction.The main results were as follows:The Organic acids(the low density acetic acid is an exception) improved phosphorus release from different synthetic phosphate compounds(DCP,OCP,FA,Fe-P and Al-P).The mobilization of phosphorus by organic acids varied with the types and concentrations of organic acids and the solubility of phosphate,the mobilizing effect of the organic acids on phosphorus was in the order:oxalic acid,citric acid,malic acid,tartaric acid and acetic acid,and the extent of mobilizing increased with the increment of organic acid concentration when extracting agent was the same organic acid.The pH-value became higher after organic acids were added,and variance of pH-value was little at low-concentration but significant at high-concentration.