Hòa tan của Florua môi trường bán khô cằn Florua (F) là một yếu tố quan trọng bởi vì nó có nhiều ứng dụng và sử dụng. Nó được sử dụng trong sản xuất phân bón phosphate, thuốc trừ sâu, và nhiệt độ cao nhựa. Florua xuất hiện tự nhiên trong đất. Ngoài ra, flo được coi là chất gây ô nhiễm phytotoxic phổ biến nhất. Khí flo phytotoxic nhất bao gồm florua hiđrô (HF) và tetrafluoride silic (SiF4) (Viện Khoa học Quốc gia, 1974). Tổng F-nội dung của đất tự nhiên khoảng giữa 200 và 300 mg / kg (Worl. | 13 Solubility of Fluoride in Semi-Arid Environments . Reddy Michelle M. Patterson J. Daniel Rodgers Richard E. Jackson and Barry L. Perryman CONTENTS Introduction Case Study of F-Solubility in Semi-Arid Soil Conclusions Acknowledgments References INTRODUCTION Fluoride F- is an important element because it has a wide variety of applications and uses. It is utilized in the production of phosphate fertilizers insecticides and high-temperature plastics. Fluoride occurs naturally in soils. Additionally fluorine is regarded as the most common phytotoxic pollutant. The most phytotoxic fluorine gases include hydrogen fluoride HF and silicon tetrafluoride SiF4 National Academy of Science 1974 . The total F- content of natural soils ranges between 200 and 300 mg kg Worl et al. 1973 . The most important naturally occurring F- minerals include fluorite CaF2 fluorapatite Ca5 PO4 3F cryolite Na3AlF6 and fluorophlogopite KMg3AlSi3O10F2 Elrashidi and Lindsay 1986 . In addition to these natural sources F- is deposited in soil through a variety of anthropogenic activities such as mining aluminum smelting fertilizer production burning fossil fuels and longterm application of phosphate fertilizers Drury et al. 1980 Polomski et al. 1982 Adriano 1986 Rutherford et al. 1994 Arnesen and Krogstad 1998 Vedina and Kreidman 1999 . Once F- is released into soil water it undergoes several geochemical processes including metal complexation adsorption and precipitation processes Figure . These chemical processes in turn control the solubility plant uptake and mobility of F- in the soil subsurface ecosystem. Fluoride is beneficial in small doses to animals and humans however in excess it becomes toxic. Relative to the risk of F- contamination our knowledge of F- mineral dissolution and precipitation processes in natural soils particularly in semi-arid soils is very limited. 2003 by CRC Press LLC F emission Soil Surface Desorption o Ừ 0 o ỊŨ 0 n Adsorption CO O .
