Abstract:To solve Jiangxi tungsten and other heavy metal pollution problems, an indoor simulated acid rain leaching test was conducted in this study. In the test, we studied the fixed effect of soil amendments such as rice husk biochar (BC), natural zeolite (ZE) and rice husk biochar-natural zeolite (CO) on the soil Pb, Cd and W under the conditions of acid rain with different pH (3.1, 4.5 and 5.8). The results showed that acid rain increased the leaching risk of heavy metals, and the lower the pH, the greater the risk. The addition of BC, ZE and CO effectively improved the acid buffering capacity of soil, and increased the pH of the leaching solution by 0.53, 0.23 and 0.58 units on average, respectively, and increased the soil pH by 0.27, 0.09 and 0.17 units on average after leaching. After leaching of simulated acid rain with pH=4.5 and pH=5.8, the total leaching amounts of Cd and Pb in CO treatment were significantly lower than those in untreated soil, and decreased by 32.1%, 38.0% and 36.0%, 32.7%, respectively, compared with untreated soil. W was different from Cd and Pb. Under the condition of simulated acid rain with pH=3.1, the addition of amendments had no significant effect on the total leaching amount of W. When the pH of simulated acid rain were 4.5 and 5.8, the total leaching amounts of W increased by 44.3 μg/L and 53.8 μg/L in the treatment of applying biochar alone, respectively. However, biochar combined with zeolite treatment reduced the total leaching amounts of W by 6.0 μg/L and 7.1 μg/L, respectively. In conclusion, biochar combined with zeolite could more effectively prevent leaching loss of Pb, Cd and W from contaminated soil under acid rain conditions, which could provide a reference for prevention and control of heavy metal pollution in tungsten ore areas.