The Research On The Sensitivity Of The Acid Rain Leaching To The Cd,F And K In Soil Of Chengdu

Now, acid rain is one of the global problems. Because of the long-term role of acid rain, nonmetal element F and heavy metal element Cd in soil may dissolve, at the same time, nutritional element K may be run off. A soil column leaching experiment was designed in order to investigate the effect of simulated acid rain on release of Cd, F, K from soil. The subject of this paper is to offer scientific basis to the pollutive control and the risk appraisement of agricultural-geological environment.The chemical action of Cd in top soil samples in Chengdu with acid rain leaching has been studied in this paper. The effects of pH, velocity of flow, and component part of acid rain on the release of Cadmium from soil were studied. And further more, the influence of the content of CO₃^2- in the soil sample on the release of Cd,F,K has been studied ,too. The sensitivity to acid rain of Cd,F and K in the soil samples from suburbs of Chengdu has been studied.It is shown by the results that for the same soil, the amount of Cd and F increase along with the reducing of pH, that the concentration of Cd,F,K will far increase to a biggest value and then decrease, that from leaching speed comparison test, the faster flow of acid rain, soil cadmium leaching the greater volume, that NO₃ has great influence on the leaching amount of Cd and K and that when Carbonate added to a certain amount, the leaching of cadmium increased. It has been found that the pH difference before and after leaching and the dissolution of Cd,K from the soil samples are significantly correlated. It is found that the leaching amounts of Cd, F are close related to its exchange species, and that the concentrations of leached Cd and F do not reach the value that can cause harm.