Effect of soil in pine-oak mixed forest on pH,and contents of Cd, Pb,and Zn in simulated rainfall leachate
[Objective] Effects of the soil in pine-oak mixed forests on concentrations of Cd,Pb and Zn in rainfalls with different pH levels were studied to improve water quality management in water source region.[Method] Soil samples were collected from layer A and layer B underneath the pine-oak mixed forests in H uoditang forest region of Ningshan County,Shaanxi Province.By simulating the penetration of rainfalls with different pH and different mass concentrations of heavy metals (No heavy mental (M0),annual statistical minimum (Min),annual average (Mv),and annual statistical maximum (Max)) through soil layer A and layer AB,the changes of pH and mass concentrations of heavy metals in the leachate were analyzed.[Result] (1) When the pH values of simulated rainfalls were 4.0-8.0,the pH values of leachates passing layer A and layer AB were 6.8 to 7.0 and 7.0 to 7.3,respectively.(2) The mass concentrations of Cd,Pb,and Zn in the leachate passing layer A were 0.14-0.31,17.25-78.57,and 8.57-46.09 μg/L,respectively,and those in the leachate passing layers AB were 0.14-0.25,7.52-32.72,and 6.35-22.33 μg/L.(3)The concentrations of Cd,Pb,and Zn in leachates after rainfalls with different heavy metal concentrations were in a decreasing order of Min＞Mv＞Max.[Conclusion] Forest soil could regulate and stabilize the acidity of rainfall.Soil layers A and AB had both adsorption and desorption effect on Cd,Pb,and Zn.Soil layer B only had adsorption effect.After the simulated rainfall through soil in pine-oak mixed forests,the mass concentrations of Cd and Zn accored with national standards of drinking water and Pb was 1.5 to 7.8 times with the standards.
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NSTL
万方数据
维普
