Liu Fei, Zhang Yan-Yi, Yan Yu-Peng, Liu Fan, Tan Wen-Feng, Liu Ming-Ming, Feng Xiong-Han
Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtze River), Ministry of Agriculture, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, China.
Huan Jing Ke Xue. 2013 Nov;34(11):4482-9.
The sorption and desorption characteristics of four kinds of organic phosphorus with different molecular structures (glycerophosphate (GP), glucose-6-phosphate (G6P), adenosine triphosphate (ATP), and myo-inositol hexakisphosphate (IHP)) on three kinds of aluminum (oxyhydr)oxides (amorphous Al(OH)3, boehmite, and alpha-Al2O3) were studied. The underlying mechanisms were also illustrated. Results showed that the maximum sorption amounts of OP onto Al (oxyhydr)oxides, on a per gram dry weight basis, decreased as following: amorphous Al(OH)3 > boehmite > alpha-Al2O3. This mainly related to the mineral crystallinity and surface heterogeneity. With the exception of sorption of IHP on amorphous Al (OH)3, the maximum sorption density decreased with increasing molecular weight (MW) of OP, following the order: GP > G6P > ATP > IHP. However, the sorption amount of IHP on amorphous Al (OH)3 was much higher than those of other OP, due to the transformation of surface complexes of IHP to surface precipitation and thus enhancing the sorption. The sorption kinetics results showed that sorption of OP underwent the first onset rapid sorption, i. e. a certain amount of sorption occurred within an onset extremely short period, and a following long and slow sorption process. Amorphous Al (OH)3 had the greatest onset rapid sorption density, and the onset rapid sorption density of OP on Al (oxyhydr) oxides decreased with increasing MW. Desorption capacities of OP by KCl and citrate solutions related to the surface affinity between OP and boehmite. Initial desorption percentages by KCl decreased in the order: G6P (10.53%) > GP(6.91%) > ATP (3.06%) > IHP (0.8%). The maximum desorption percentages of OP by citrate were 4-5 times greater than those by KCl. During resorption process of P by KCl, the maximum desorption rate achieved after a fast desorption in a few hours, followed by diffusion-resorption during which the desorption percentage gradually decreased. Specially, both diffusion-resorption and surface precipitation promoted the resorption of IHP on mineral surface. Conclusively, the strong specific sorption of OP occurs on the surface of Al (oxyhydr) oxides, and molecular structure and size of OP as well as the crystallinity and crystal structure of minerals are the key factors affecting the interfacial reactions and environmental behaviors of OP.
研究了四种分子结构不同的有机磷（甘油磷酸酯（GP）、6-磷酸葡萄糖（G6P）、三磷酸腺苷（ATP）和肌醇六磷酸（IHP））在三种铝（氢）氧化物（无定形Al(OH)₃、勃姆石和α-Al₂O₃）上的吸附和解吸特性，并阐述了其潜在机制。结果表明，以每克干重计，有机磷在铝（氢）氧化物上的最大吸附量依次为：无定形Al(OH)₃＞勃姆石＞α-Al₂O₃。这主要与矿物结晶度和表面非均质性有关。除IHP在无定形Al(OH)₃上的吸附外，有机磷的最大吸附密度随其分子量（MW）的增加而降低，顺序为：GP＞G6P＞ATP＞IHP。然而，IHP在无定形Al(OH)₃上的吸附量远高于其他有机磷，这是由于IHP表面络合物转化为表面沉淀，从而增强了吸附。吸附动力学结果表明，有机磷的吸附经历了初期快速吸附阶段，即在极短的初始阶段发生一定量的吸附，随后是漫长而缓慢的吸附过程。无定形Al(OH)₃的初期快速吸附密度最大，有机磷在铝（氢）氧化物上的初期快速吸附密度随分子量增加而降低。KCl和柠檬酸盐溶液对有机磷的解吸能力与有机磷和勃姆石之间的表面亲和力有关。KCl的初始解吸百分比顺序为：G6P（10.53%）＞GP（6.91%）＞ATP（3.06%）＞IHP（0.8%）。柠檬酸盐对有机磷的最大解吸百分比比KCl高4-5倍。在KCl对磷的再吸附过程中，最大解吸速率在数小时的快速解吸后达到，随后是扩散再吸附过程，在此过程中解吸百分比逐渐降低。特别是，扩散再吸附和表面沉淀都促进了IHP在矿物表面的再吸附。总之，有机磷在铝（氢）氧化物表面发生强烈的特异性吸附，有机磷的分子结构和大小以及矿物的结晶度和晶体结构是影响有机磷界面反应和环境行为的关键因素。
