EFFECT OF STIMULATED ACID RAIN ON HYDROCHEMICAL CHARACTERISTICS OF RED SOIL AQUIFER AND ITS CORRELATION ANALYSIS

Authors：Song, Yongsheng; Wang, Xiaodong; Liu, Renli; Yin, Li; Liao, Yonghui; He, Genhe^*

Source：FRESENIUS ENVIRONMENTAL BULLETIN, 2022, 31(11): 11073-11082.

• Red soil
• Acidification
• Leaching
• Heavy metals
• Nitrogen

Acidification had a great impact on the aquifer water environment. However, it was not clear how acidification affects aquifer environmental factors and what was the correlation between these environmental factors. So, we studied the effect of simulated acid rain (SAR) on hydrochemical characteristics of red soil aquifer and its correlation analysis. The results showed that SAR caused the pH value of leachate to decline, and the acidification degree of leachate increases significantly with the treatment time. There was a positive correlation between the cumulative release of nitrogen and heavy metals to the environment and the leaching time. Moreover, the leaching of nitrogen and metal ions were affected by filter media, the larger particle size, the higher leaching efficiency. Continuous acidification will affect the transformation of soil nitrogen, activate heavy metals, and increase its harm to soil and groundwater environmental pollution. Further, negative correlations between pH and NH4+-N (r=-0.61; p<0.01), NO2--N (r=-0.80; p<0.01), NO3--N (r=0.34; p<0.01), Fe (r=-0.60; p<0.01), A1 (r=-0.55; p<0.01), Mn (r=-0.77; p<0.01), Cu (r=-0.42; p<0.01) and Cd (r=-0.65; p<0.01) were found. In addition, the correlation between the leaching rate of three nitrogen and metal ions showed their own characteristics, NH4+-N and NO2--N showed positive correlations with Fe, Al, Mn, Cu and Cd.