摘要
【目的】研究松栎混交林土壤对不同降雨淋溶液pH及Cd、Pb、Zn质量浓度的影响, 为水源地水质管理提供科学依据。【方法】在陕西宁陕火地塘林区分层（A层和B层）采集松栎混交林林下土样，通过模拟不同pH值和不同重金属质量浓度（无重金属（M0）、降雨重金属质量浓度全年统计最小值（Min）、全年统计平均值（Mv）、全年统计最大值（Max））的降雨下渗透过森林A层和AB层土壤的方法，分析淋溶液的pH值及重金属质量浓度的变化。【结果】（1）pH值为4.0，5.0，6.0，7.0和8.0的降雨透过A层土壤后，淋溶液pH为6.8～7.0；透过AB层土壤后，淋溶液pH为7.0～7.3。（2）重金属质量浓度为M0、Min、Mv和Max的降雨淋溶A层土壤后，淋溶液中Cd、Pb、Zn的质量浓度分别为0.14～0.31，17.25～78.57，8.57～46.09 μg/L；淋溶AB层土壤后，分别为0.14～0.25，7.52～32.72，6.35～22.33 μg/L。并且A层土壤淋溶液中的Cd、Pb、Zn质量浓度均大于AB层土壤淋溶液。（3）重金属质量浓度为Min、Mv和Max的降雨淋溶土壤后，淋溶液中的Cd、Pb、Zn的质量浓度总体上均表现为Min＞Mv＞Max。【结论】森林土壤对降雨的pH有调节和稳定作用；随降雨中重金属质量浓度的不同，A层和AB层土壤对Cd、Pb和Zn既有解吸作用又有吸附作用，其中B层土壤主要为吸附作用。降雨透过松栎混交林土壤后，Cd和Zn质量浓度符合国家饮用水卫生标准，而Pb质量浓度是标准的1.5～7.8倍。
【Objective】Effects of the soil in pineoak 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 Huoditang 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.
出处
《西北农林科技大学学报（自然科学版）》
CSCD
北大核心
2014年第6期107-114,共8页
Journal of Northwest A&F University(Natural Science Edition)
基金
林业公益性行业科研专项(201004036)
关键词
松栎混交林
土壤
降雨
重金属
pine-oak mixed forest
soil
rainfall
heavy metals
