| World-wide acid rain and heavy metal pollution has become a hot environmental topic which has been given attentions to widely currently. For its particular geology and physiognomy as well as climate conditions, the frequency, extent and intensity of acid rain in Chongqing have been serious all the while. Secular eluviation of acid rain, which caused soil acidification and elution of heavy metals from soil has aggravated heavy metal pollution farther. Enrichment of heavy metal in vegetation has severely influenced quality and security of crops. Furthermore, heavy metal could get into human body through food chain and endanger human health finally.In this article, Acidic and neutral purple soil which are representative in Chongqing were chosen as samples for testing and characteristics of morphology and transference as well as vegetable validity of Cd, Hg and Pb in purple soil were discussed by pot experiments under condition of simulant acid rain .This study can provide scientific guidance to prevent Cd, Hg and Pb in soil from engendering harm through food chain and offer scientific and theoretic basis for forecasting and controlling Cd, Hg and Pb pollution in soil.The results were as follows:For the two kinds of soil, relationship between amount of leaching heavy metal and pH of leachate accorded with parabolic curve of second degree. With raise of pH of acid rain, the highest pH of leachate increased gradually while amount of infiltrate solution needed would also increased. The highest pH value of leachate of neutral soil was higher man that of acidic soil while corresponding amount of infiltrate solution was lower than that of acidic soil.The relationship between concentration of Cd in leachate of acid soil and amount of infiltrate solution accorded with parabolic curve of second degree. Furthermore, the highest concentration of Cd decreased remarkably with raise of pH of acid rain. For neutral soil, concentration of Cd in...
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