The influence of organic acids on aluminum oxide adsorption of phosphorus

Aluminum oxide is widely distributed in tropical and subtropical regions acidic soil type of H&X brown fused aluminium oxide, its adsorption of phosphate radical fixed is acidic soil phosphorus deficiency and the main reasons for low phosphorus availability in [1 ~ 3]. On the phosphorus absorption mechanism of aluminium oxide, oxalic acid and phosphoric acid root in aluminum oxide on the surface of the competition effect, etc. There are some studies [4 ~ 10], but USES the aluminum oxide in alkaline conditions (pH 8 (2) more
abstract  : with different coordination anion (sulfuric acid, phosphoric acid, oxalic acid, citric acid root) composite aluminum oxide as an object, oxalic acid, citric acid, etc are studied by equilibrium adsorption concentration and pH of the influence of aluminum oxide H&X buy silica sand of phosphorus, and organic acids affect phosphorus adsorption mechanism. Results show that the largest of the six synthetic aluminium oxide phosphorus uptake (Xm) between 0 ~ 0 838 tendency for 189 g, with Al (OH) x has the highest phosphorus uptake, "aluminum citrate complexes (Al CA) lowest phosphorus uptake; Organic acid concentration increased, the phosphorus uptake of aluminum oxide is reduced, and the influence degree of the citric acid is higher than oxalic acid; And pH of 2 of oxalic acid and tartaric acid, Al (OH) x secondary adsorption quantity minimum for phosphorus, and organic acid pH 3, Al (OH) x to reach the highest, the secondary adsorption of phosphorus organic acid solution pH increased from 4 to 9, aluminium oxide changed or gradually reduce p uptake. Organic acids and phosphorus mixed join compared with single phosphorate, pH 3 when difference is small, the most significant difference when the pH 4 ~ 6, pH 7 ~ 8 and decreased; Organic acids lower aluminum oxide phosphorus uptake mechanism includes two aspects of acid dissolution and complex competition, when pH 2 is given priority to with the former, pH 3 ~ 9 is given priority to with the latter, and the adsorption on the surface of the aluminum oxide point of coordination anion is affinity