Kinetics and Evaluation of Heavy Metals and Nutrients in Leachates from Fertilizers Using Soil Columns

Since there was no data about heavy metals content in fertilizers used in Palestine, this study could provide useful new data for the Ministry of Agriculture in Palestine. Measured levels of heavy metals in fertilizer show further information about their rate in fertilizers. Heavy metals: zinc (Zn+2), manganese (Mn+2), copper (Cu+2) and iron (Fe+3) concentrations that leached out from fertilizers were determined by using flame atomic absorption spectrophotometer (AAS). In addition to that, some nutrients: phosphorus as P2O5, potassium as K2O, and nitrogen as NO3- concentrations were determined by using two methods. The first method was ultraviolet visible (UV-VIS) method, which was used for the analysis of phosphorus as P2O5, nitrogen as NO3- (in soil samples and one sample of compound fertilizer), and potassium as K2O. The second method was photometer nitrate instrument, which was used for the analysis of nitrogen as NO3- in ten water samples. One sample of agricultural red soil from Nablus and one sample of compound fertilizer 20/20/20 (N/ P/ K) used in Palestine were both taken. Statistical analysis and figures were used to help understand the processes occurring in soil. The results indicate that compound fertilizer 20/20/20, which is used in Palestine, is a main source for many heavy metal pollutants and nutrients. Linear Regression Statistical test show that there is a significant variation, in the concentration of the heavy metals and nutrients in samples of fertilized soil and leachate water samples. So it can pollute the environment by the accumulation of heavy metals such as Cu+2, Mn+2, Fe+3 and Zn+2 in addition to nutrients such as P2O5 and K2O on the surface of the soil. It can also leach to the ground water and pollute it with NO3-, Fe+3, Mn+2 and Zn+2. Thus, these results suggest that the fertilized soil with compound fertilizer 20/20/20 is rich with various toxic heavy metals particularly Cu+2, Mn+2 and Zn+2, as well as other nutrients, particularly NO3- which causes ground water pollution.