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以存在不同配位阴离子 (硫酸根、磷酸根、草酸根、柠檬酸根 )时合成的铝氧化物为对象 ,用平衡吸附法研究了草酸、柠檬酸等的浓度和 pH对铝氧化物吸附磷的影响 ,并讨论有机酸影响磷吸附的机制。结果表明 :六种合成铝氧化物的最大吸磷量 (Xm)介于 0 189～ 0 838mmol/ g ,以Al(OH)x的吸磷量最高 ,“铝 柠檬酸”复合物 (Al CA)的吸磷量最低 ;有机酸浓度升高时 ,铝氧化物的吸磷量降低 ,且柠檬酸的影响程度高于草酸 ;先加 pH为 2的草酸或酒石酸 ,Al(OH)x对磷的次级吸附量最低 ,而有机酸pH为 3时 ,Al(OH)x对磷的次级吸附量达最高 ,有机酸溶液 pH由 4增至 9,铝氧化物吸磷量变化不大或逐渐降低。有机酸与磷混合加入同单加磷相比 ,pH 3时差异较小 ,pH 4～ 6时差异最显著 ,pH 7～ 8时又减小 ;有机酸降低铝氧化物吸磷量的机理包括酸性溶解和络合竞争两方面 ,在 pH 2时以前者为主 ,pH 3～ 9时以后者为主 ,且铝氧化物表面的吸附点位对供试配位阴离子都是亲合的
In the presence of different coordination anions (sulfate, phosphate, oxalate, citrate) aluminum oxide synthesis for the study by equilibrium adsorption oxalic acid, citric acid concentration and pH on the adsorption of aluminum oxide phosphorus Affect, and discuss the mechanism by which organic acids affect phosphorus adsorption. The results showed that the maximum phosphorus uptake (Xm) of the six kinds of synthetic aluminum oxides ranged from 0 189 to 0 838 mmol / g, the highest phosphorus uptake by Al (OH) x and the “aluminum citrate” Of the total phosphorus uptake was the lowest. When the concentration of organic acid increased, the phosphorus uptake of aluminum oxide decreased, and the influence of citric acid was higher than that of oxalic acid. Adding oxalic acid or tartaric acid with pH 2, While the secondary adsorption capacity was the lowest. When the pH value of organic acid was 3, the secondary adsorption capacity of Al (OH) x to phosphorus was the highest, the pH value of organic acid solution was increased from 4 to 9, and the phosphorus uptake of aluminum oxide changed little or gradually reduce. Compared with the single addition of phosphorus, organic acid and phosphorous had a little difference at pH 3, the most significant difference was between pH 4 and 6, and decreased when pH was between 7 and 8. The mechanism that organic acids reduced the phosphorus uptake by aluminum oxides included Acid dissolution and complexation competition, the former was dominated by pH 2, the latter was dominated by pH 3 ~ 9, and the adsorption sites on the surface of aluminum oxide were all compatible with the anions