| Popis: |
In this study, the soil column experiment was adopted to investigated the release characteristic of P from soil by citric acid leaching. The results showed that the P release characteristics were different from each other under various citrate concentrations. At high concentration (50 mM) treatment, P concentration of effluents increased rapidly with effluent volume at the beginning, reached the maximum value after approximately 150 ml solution had passed through the columns. For the column treated with 5 mM of citric acid, the P in leachates was increased gradually to the maximum concentration, and then approached a relatively stable level during the 1000-3050 ml effluent volume. For low concentration (0.5 mM) treatment, the level of P in the effluents has always been very low, though a small peak was observed during the leaching. |
