Radioactivity and fluoride contamination derived from a phosphate fertilizer plant in Egypt

The environmental pollution caused by the wastewater from a phosphate fertilizer plant in Egypt was investigated. The concentrations of radionuclides and fluoride in phosphate fertilizer (raw materials. end products and by-products) and other types of fertilizer samples were measured. The concentrations of these elements were also measured in environmental samples (water, sediment and plant) collected from the proximity of outlet of wastewater discharge pipes of the phosphate fertilizer company. The fluoride concentration was ranged from 0.03 to 0.25 mg/g, 0.002 to 0.006 mg/g, 0.42 to 1.88 mg/g and 0.44 to 7.3 mg/l for phosphate fertilizer, other types of fertilizer, sediment and water samples, respectively. The activity concentrations of Ra-226 were ranged from 244 to 1312 Bq/kg, 0.6 to 12.1 Bq/kg, 15.4 to 33.8 Bq/kg, 0.06 to 1.3 Bq/l and 8.9 to 17.3 Bq/kg for phosphate fertilizer, other types of fertilizer, sediment, water and plant samples, respectively. The Th-232 activity concentrations were ranged from 0.7 to 24 Bq/kg, 0.7 to 14.5 Bq/kg, 10.4 to 19.3 Bq/kg, 0.02 to 0.16 Bq/l and 2.0 to 29.8 Bq/kg for these samples, respectively. Also, the K-40 activity concentrations were ranged from 2.1 to 1.4 Bq/kg, 2.1 to 5313 Bq/kg, 128 to 281 Bq/kg, 0.14 to 0.6 Bq/l and 686 to 977 Bq/kg for these samples, respectively. Low content of Cs-137 was determined in only two phosphate fertilizer samples (F2 and F3: mean 1.3 Bq/kg) and in most of sediment samples (with range 1.0-2.4 Bq/kg). The radium equivalent, as a radiation hazard index, was ranged from 284 to 1316, 9.6 to 432 and 47 to 70 Bq/kg for phosphate fertilizer, other types of fertilizer and sediment samples, respectively. The results indicated that the wastewater polluted with fluoride produced from the phosphate fertilizer company may be affecting the environment. The radioactivity content measurements indicated that the environment may be slightly affected with low concentrations of Ra-226 and Th-232 isotopes due to the discharged wastewater from the phosphate fertilizer industry. On the other hand, the results of comparison studies for radioactivity concentrations are also presented and discussed. (C) 2009 Elsevier Ltd. All rights reserved.