CAJ | 학술논문

为阐明茶树高富集土壤氟的化学机制，采用动力学方法研究了茶树根系分泌柠檬酸对茶园土壤氟形态及其在土壤固-液相分配的影响。结果表明，土壤溶出液的pH和电导率随溶出时间的增加而逐渐减小。土壤氟的释放存在快速释放和慢速释放两个阶段，呈现初始（0~6 h）溶出浓度较高，而后（6~10 h）逐渐减缓的趋势。一级动力学方程、Elovich方程、扩散方程、双常数方程均对土壤氟的溶出过程有较好的拟合，决定系数（R 2）均大于0.91。土壤溶出液中的游离态氟和总氟的释放量随柠檬酸浓度的升高而增加，反应开始前2 h的高浓度柠檬酸溶出液中Al-F络合物的浓度较大，反应开始前1 h的Al-F络合物主要以AlF3为主，占氟溶出总量的90％左右；随着溶出时间的延长，AlF+2的溶出量逐渐增大，并逐渐超过AlF3。高浓度柠檬酸促进土壤氟的溶出释放，有利于Al-F络合物向AlF2+、AlF+2形态转化。
위천명다수고부집토양불적화학궤제，채용동역학방법연구료다수근계분비저몽산대다완토양불형태급기재토양고-액상분배적영향。결과표명，토양용출액적pH화전도솔수용출시간적증가이축점감소。토양불적석방존재쾌속석방화만속석방량개계단，정현초시（0~6 h）용출농도교고，이후（6~10 h）축점감완적추세。일급동역학방정、Elovich방정、확산방정、쌍상수방정균대토양불적용출과정유교호적의합，결정계수（R 2）균대우0.91。토양용출액중적유리태불화총불적석방량수저몽산농도적승고이증가，반응개시전2 h적고농도저몽산용출액중Al-F락합물적농도교대，반응개시전1 h적Al-F락합물주요이AlF3위주，점불용출총량적90％좌우；수착용출시간적연장，AlF+2적용출량축점증대，병축점초과AlF3。고농도저몽산촉진토양불적용출석방，유리우Al-F락합물향AlF2+、AlF+2형태전화。
Citric acid is one of organic acids excreted by tea plants. Here, the effects of citric acid on F forms and partition between solid and solution phases in a tea garden soil were investigated using a kinetic method. Soil solution pH and electric conductivity decreased with in-creasing reaction time. Release of F from the soil was quick at the beginning and then slowed down. Concentrations of F in soil solution were higher from 0 to 6 h than from 6 h to 10 h. Kinetic process of F release from tea garden soil fitted the first-order reaction kinetics and Elovich, diffusion and double constant equations as well, with all the coefficients of determination (R2)greater than 0.91. Amount of free F and total F in soil solution increased with increasing concentrations of citric acid. Amount of Al-F complexes released during the first two hours were greater under high than under low concentrations of citric acid. During the first 1 hour, AlF3 was the main form of Al-F complex-es, accounting for 90%of the total F released from the tea garden soil. With increasing reaction time, however, amount of AlF+2 released from the tea garden soil increased and finally surpassed AlF3. High concentrations of citric acid promoted F release from the soil and facilitated the conversion of Al-F complexes into AlF2+and AlF+2 . These results provide insights into the chemistry of high F accumulation in tea tree plants from soils.