Abstract: Effects of malic acid and succinic acid on the sorption and distribution of fluoride in tea garden soil was studied by the sampling of tea garden soil and the simulated testing. The sorption capacity of fluoride by tea garden soil was depressed to some extent in the presence of malic acid and succinic acid when the initial concentration of fluoride was lower than 0.42 mmol/L for the low concentration of the organic acids and 2.1 mmol/L for the high concentration of the organic acids. The depressed function of the two organic aicds for the sorption of fluoride in tea garden soil, however, was weakened when the initial concentration of fluoride was higher than 0.42 mmol/L for the low concentration of the organic acids and 2.1 mmol/L for the high concentrationof the organic acids. On the contrary, there was a distinct enhancing function for the sorption capacity of fluoride in tea garden soil in the presence of the two organic acids with increasing the initial concentration of fluoride, and the enhancing function of malic acid was larger than that of succinic acid. The residual species was the major form and water soluble species was secondary form for sorbed fluoride under the control treatmentand in the presence of malic acid and succinic acid. There were also differences in the distributionand transformation of sorbed fluoride in tea garden soil in the presence of the different organic aicds and their concentrations, but the general distribution law of sorbed fluoride was in the order: residual>water soluble>organic≈Fe-Mn oxide>exchangeable.

Key words: tea garden soil, fluoride, malic aicd, succinic acid, sorption, distribution